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Cadillac CTS FAQ

Cadillac CTS Frequently Asked Questions

(Other Cadillac FAQs) (The CTS-V FAQ)

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• Checking and Clearing Trouble Codes
• What are the gear ratios in the Cadillac CTS-V?
• How do I remove the shift knob?
• Tremec T56 Series Transmission Service Manual (PDF)
• CAGS modification (remove the 1st-4th shift) (See discussion #1 and #2)
• How do I reset the G-Monitor on the Driver Information Center?
• How do I install a radar detector (specifically a Valentine 1)?
• Where can I get switched accessory power?
• Where can I get floor mats for my Cadillac CTS-V? (Here)
• How do I disable the daytime running lights? (Click here) (Discussion)
• How do I change the headlights on a Cadillac CTS / CTS-V?
• How do I replace the Onstar Antenna on the rear window?
• Can I play DVDs while the car is moving?
• Dealer / Person Tracking using Navigation
• Radio Schematics: (Bose Speakers)
• Navigation Schematic
• How to Relearn the Electronic Throttle Control (ETC)
• How to reprogram the Tirepressure Sensor guage
• Oil Temperature Guage Issue Resolved
• What's the difference between the Corvette LS6 and the Cadillac CTS-V LS6?
• Cadillac CTS-V Technical Repair Guide
• How is the Cadillac CTS-V intended to perform?
• What are the wheel specifications on the Cadillac CTS-V?
• Why does the driveline on my Cadillac CTS-V make a clunking noise?
• How do I clean the seats in my Cadillac CTS-V?
• Does the Cadillac CTS-V come with wheel locks? (Yes. See discussion)
• How do I remove the door panels on my Cadillac CTS-V?
• How do I remove the driver's side visor on my Cadillac CTS-V (with homelink)?
• How do I change the rear differential fluid on my Cadillac CTS-V?
• What brake pads will work on the Cadillac CTS-V? What are the specifications?
• What stock tires should I get for my Cadillac CTS-V?
• The key wont start my Cadillac CTS-V. How do I reprogram my key FOB?
• Different parts in regards to Cadillac CTS vs Cadillac CTS-V
• How do you set the "Go Home" address in the navigation system on the Cadillac CTS-V?
• Cadillac's response to various common issues
• How To Instructions: Change Cadillac CTS-V Transmission Fluid
• How To Instructions: Cadillac CTS-V Differential Lube Change
• How do I change the oil on my Cadillac CTS-V?


CHECKING AND CLEARING TROUBLE CODES (See discussion) (back to the top)

For 2003/4 CTS with Navigation System:

Press simultaneously the BAND button and bottom NAV button on the left side of the LCD and release. All instrument cluster and HVAC control lights will flash momentarily, then go off, and then a menu will appear on the LCD to read and clear DTCs. (Does not work with CTS-V)

For 2003/4 CTS non Navigation System:

Press and hold the F1 and F6 buttons simultaneously; the Driver Infomation Center (DIC) will clear and a menu will appear to read and clear DTCs. (Need to confirm this method)

Refer to the following site for DTC list:

Reading DTCs may give you insight to vehicle problems, however, this is purely diagnostic and does not allow adjustments other than clearing set codes.

WHAT ARE THE GEAR RATIOS IN THE CTS-V? (see discussion) (back to the top)

Gear-Ratio-MPH/1000-Max MPH

Same 1-6 ratios as a Z06, but different than a regular C5 and F-bodies.

Tremec T56 (M12)
Type: six speed rear-wheel-drive, manual overdrive transmission
Maximum engine torque: 400 lb-ft (542 Nm)
Maximum validated gross vehicle weight: 4000 lb (1680 kg)
Case material: aluminum
Center distance: 85mm
Fluid type: DEXRON III
Transmission weight: wet: 54.9 kg (121 lb)
Fluid capacity (approximate) dry: 3.8L (4.0 qt)

*Combination of double-cone and triple-cone synchronizers on all forward gears.
*Needle bearings on all forward gearsets
*5th and 6th gear synchros located on countershaft (allowing selection of 5 & 6 without affecting 1 - 4) contributing to easier shifting.


HOW DO I REMOVE THE SHIFT KNOB? (see discussion and pictures) (back to the top)

Similar to the C5 Corvette (click here) with one difference: Put tranny in reverse, put some forward pressure on knob and pull straight up. The knob basically snaps on the shifter rod. The reason I know is I thought mine was a screw on knob and tried to turn it and broke the plastic inside the knob. (They are replacing under warranty. The knob and boot assembly cost 175.00) When I pulled it straight up it came off. You will see once it's off the notch on the shifter rod that it snaps in to. The boot and trim release at the back of the console area and there are tabs at the front of the boot. It's actually quite easy to remove. There is about a two inch thick piece of foam between the console and transmission hump for noise.



Press the botton on the top far left of the steering wheel until the Driver Information Center shows the G-Meter display. Press and hold the bottom button (page back) until the G-Meter resets.


HOW DO I INSTALL A RADAR DETECTOR (SPECIFICALLY A VALENTINE 1)? (see discussion) (back to the top)

How do I install a Radar Detector (specifically a V1)?
In this instance I will assume that you using a V1. V1 = Valentine 1.

A little background on V1, Mike Valentine originally designed one of the very first escort radar detectors and has since left the company and started his own product line, his products are generally considered the best available on the market however they come from heavy price tag. Beware you can only by a Valentine 1 from the Valentine 1 web site there are no deals to be found anywhere. I have run my V1 in parallel with a K-40 (professionally installed) on one occasion and on another against a Bell something or other, nothing compares to the V1 – in my opinion. It’s pricey but well worth the price. Some users note that they get a lot more false alarms using the V1, but that’s because it’s significantly more sensitive than anything they have used before. But hey the V1 is the only detector I know of that’s programmable, if it’s picking up every set of K-mart doors you can turn down the sensitivity!

For those of you who do not yet have a V1, it will come with two styles of mounting: a belt holster like clip that’s used for visor mounting and traditional suction cup mounts. For power it uses standard RJ-11 telephone line cord. This is the wire that runs from your home telephone to the wall jack. It is relatively flat and has four conductors; I believe some is supplied in the V1 box. Worst case you go to your local hardware store or radio shop and buying the smallest length of telephone cord you can find 3 or 6 feet (black colored cable is preferred). If you have a three foot cord with male connectors on both ends, simply cut that cable in half. You’ll only need one piece, the other is just there are as a backup.

I installed on my V1 into my CTSV without the remote display unit available, I do have that in another vehicle. My V1 is suctioned cupped to the windshield directly above and beside the inside rearview mirror. My instructions cover mounting the radar detector in this location. To begin the installation process first make sure that he vehicle has been off - not even a key in the ignition for at least 30 minutes (I’ll explain why later). It is preferable that you do this outside in the sunlight as opposed to indoors in a shop environment or any other place without bright lighting. You will need a wire stripper, crimper tool, some connectors (some should be included in the V1 installation kit), and a 12 V test light.

Phase 1 Remove the overhead console, as follows – (3 mins.)

1. Remove the Dimmer knob (would you call this a knob?) by pulling straight down on it (gently yet forcefully), or get your nails under the head of it. It will snap right out.
2. If you have a sunroof - I WOULD GUESS/ASSUME that the control knob for this is removed in a similar form to #1 above.
3. Once these items are removed grab at the back/rear of the console and once again pull down (you will hear some plasticy snapping noises - these are the clips - usually not breaking just giving as expected). I don't recall if the front is also clipped in or just wedged in under a lip.
4. Remove electrical connections (if necessary) or just let the thing hang, we did not need to remove it for the 10 minutes we had it down.

Phase 2 – Wiring (5 mins.)

You should have at least 1 approximately 18 inch long piece of telephone cable with one bare/cut end, the other end should have an RJ-11 MALE telephone type connector on it.

1. (This and the next step are the most difficult part of this operation) Carefully pry a small (width) the area of the headliner away from the mounting near the windshield.
2. Then feed the bare end of the cable from the windshield under the headliner to the opening where the overhead console normally appears.
3. You may wish to (roughly) place the V1 in it’s final mounting place, on your windshield, and if need be, trim back the bare end of this cable – I left most of my extra cable tucked up (and hidden) in the headliner, so that in case I need/want to move the detector to a different (yet still reasonably close) location, it would be easy. I first had mine on the passenger side of the inside rear view mirror, the decided to move it to the driver’s side.
4. With the exposed end of the cable now in the hole of the headliner, trim back about two to three inches of outside insulation, exposing 4 insulated wires.
5. At this point if you’re not using the remote display unit (and this install assumes that), you can cut the yellow and black wires off completely they are not used a stand-alone installation.
6. Blue wire with WHITE stripe (adjacent to the black wire in the connector - if we call the black wire position 2 in that row (there are 4 wires) then the blue/WHITE stripe wire is position 3) = +12V delay switched. (see below)
7. Use wire clips to attach to one of the seeming to be ignition hot wires and another to a ground.
8. Strip about three-quarters of an inch of insulation off both the red and green wires and crimp the appropriate blade type connectors onto them (I can supply pic of these connectors if need be).
9. Insert the 2 bladed connectors into the 2 wire clips.
10. Plug in your V1 and turn it on. If it fails to power up (and make the soon to be all familiar self test sounds), swap (reverse) the connections that you plugged into the wire clips in Step 9. You will NOT do any harm to the V1 if the power to it is reversed, it just won’t power up.

Phase 3 – Tidy up (2 mins.)

1. Tuck the wires and wire harness back into place, pull extra telephone wire up and out of the way.
2. Reinstall the overhead console by CAREFULLY smacking the console (with properly aligned pins to holes) back into place. We had to smack it pretty hard (at each clip).
3. Clip the knobs back into place.
4. Mount your V1 in desired location, tuck cable behind review mirror.

*The ignition hots didn’t turn off with the ignition, WHY? Well our lovely CTS has “DIH”, Delayed Ignition Hot. These stay active for 10 or 20 minutes after you turn off the car, then the car computer shuts down all the power (there is something about it in the manual with a name that GM Marketing came up with). In my case, during the day my V1 only powers up when the ignition is turned on (and will stay on for a bit after the car is turned off – so if you jump out to get fuel it will stay on, but by the end of lunch it’s off). At night my V1 powers up when I hit the key fob to open the doors and again shuts off after 10 or 20 minutes after shutting down the car.


I just finished the hardwire on my Passport 8500x50 and I DO HAVE A SUNROOF - so this applies to sunroof equipped models.

First, you do not need to remove the dimmer slider or the sunroof knob. In fact, if you remove the sunroof knob a clip and two springs will fall out that are somewhat challenging to get back in.

All you need to do is pull on the back of the panel (the panel that has the knob, overhead lights, and microphone) and then the front to pop the clips out. Be careful, on my V the wire to the microphone is VERY SHORT and will not unplug. Once this is done, you can look from the passenger side and you will see two connectors. One is for the sunroof switch. The other, the one you need, is the lighting harness. Unplug the lighting harness and make your connections here.

Your wire from the radar detector can run up alongside the OnStar/mirror wiring. The upper cover adjacent to the headliner pops off, although it is a little tricky. I ran my phone cord aka power wire up through the front of the headliner just as Ben did above.

And now for tha all important wire color codes (This ONLY applies to the connector mentioned above and it may or may not apply to non-sunroof equipped vehicles):

Black = ground
Blue wire with WHITE(CORRECTION) stripe (adjacent to the black wire in the connector - if we call the black wire position 2 in that row (there are 4 wires) then the blue/white (CORRECTION) stripe wire is position 3) = +12V delay switched.

WHERE CAN I GET SWITCHED ACCESSORY POWER? (See discussion) (back to the top)

Option 1

I tapped into the harness that connects to the climate control panel. It's really easy to remove. Just open the ashtray and remove the felt tray. You'll see a screw recessed behind the tray. Loosen this screw. I had to use a magnetic driver so that the screw would stay attached to the driver when it came loose (as opposed to falling somewhere into the center console). Then you just grab the ashtray and pull straight out to loosen the clips. You'll see the harness in the back and a wire for you cigarette lighter. The harness is easy to undo but I still haven't figured out the lighter. I just let the whole thing dangle over the passenger foot well while I worked with the harness.

Looking at the harness with the wires facing away from you, the first wire in the SECOND row should be a switched 12V. If that doesn't work, it may be the 8th wire in the FIRST row. One of them is a ground and the other is hot. Use a multimeter to confirm before doing any wiring. If you find that both are ground, don't forget to start your car.

Option 2

Each of the interior outlets can be changed from a battery feed to a switched ignition feed. (One is the cigar lighter in the ashtray, the other is the auxiliary outlet in the rear of the center console.

To do that, go to the underhood fuse center and look for a bright yellow 20A fuse and a bright green 30A fuse that are in "wide" spaces (see picture below- RED callouts). Looking from the front of the car, they're kinda to the right of center and slightly above, between some relays. Anyway, these are the only fuses that you can move from side to side. The center contact is the one that eventually feeds the outlets. The contact on either side come from either the battery or the "cigar relay" (the switched feed). You use the fuse to bridge the appropriate gap:

If you want the cigar outlet to be on a switched supply, move the yellow fuse one position over in the same space. If you want the rear outlet to be switched, move the green fuse one position over. The factory fuse positions bridge the gap between the battery and the center contact.


HOW DO I CHANGE THE HEADLIGHTS ON A CADILLAC CTS / CTS-V? (See discussion) (back to the top)

It's quite complicated and takes between 1-2 hours.
You need to remove the front bumper first. In order to do this:

  • pop your hood and remove the rubber wind deflector to expose plastic push pin fasteners and two (maybe four) bolts that attach the faschia to the car. Leave the hood open.
  • you need to jack one of the front wheels up and remove it.
  • Remove the push pin plastic fasteners attaching the bumper to the car as well as loosening (but not removing) the washers underneath the lip of the bumper where it joins with the car body. This washers are located inside the bumper so you will have to crawl under the wheel well, they are right behind where that reflector is on the side of the bumper and there should be two of them.
  • Also remove the harnesses for the turn signal and foglights.
  • Put the wheel back on and remove the jack.
  • Now jack up the other side and repeat this process. There is also a row of plastic push pin fasteners along the bottom of the bumper. Remove these as well.

    If you did everything correctly, the front bumper should slide down and towards the front of the car and fall off (careful, don't let it hit the ground)

  • Now there are two bolts fastening the light housing to the car body, one on top and one below the housing. There is also a third behind the rubber insulation of the light housing. This one is the hardest to remove as it involves forcing the rubber out of the way to access the bolt. I'm pretty sure this are the only three bolts, but look for a fourth to be certain.
  • The headlight housing should only be held on by a ball and socket fastener.
  • Now pull the housing straight forward with some force and it should pop out. Remove the harnesses and you have access to the housing. How to open the housing should be pretty intuitive.

    Now that you know how to take it apart, putting it together is the same thing but in reverse order.

    Remember this could take 1-2 hours, maybe even three so plan for it. Hope this helps.

HOW DO I REPLACE THE ONSTAR ANTENNA ON THE REAR WINDOW? (See discussion) (back to the top)

  • I removed the OnStar on-glass antenna from my '04 CTS and installed a tri-band surface mount dipole antenna. (Currently OnStar uses the analog cell band)
  • I used a thin blade putty knife to remove both inside and outside parts, then used a razor blade to remove the remaining adhesive.
  • I then installed the new antenna on the inside of the car behind the sub-woofer, between the rear glass and the carpet on the rear deck (centered left to right).
  • I dressed the coax around and back up to the original coax connector and hid the entire connector/coax behind the side panel. So, all you can see is the antenna (4.5" x .8" x .1"thk)

    So far the new antenna works every bit as good as the original one.

    The LED on the right side of the mirror will turn RED, because my new antenna design is different from the on-glass design (the original antenna appears as a dead short across the coax to DC, my new antenna appears as a open circuit to DC)

    The antenna is a ANT-DB1-VDP from
    It cost ~$7. I couldnt use the TNC connector that came with the new antenna, since the connector on the end of the OnStar coax was already a TNC connector (its a press fit type), So I soldered a TNC jack onto the end of the new antenna coax. [This piece can be purchased at radioshack or a local electronics store- ed]

CAN I PLAY DVDS WHILE THE CAR IS MOVING? (See discussion) (back to the top)

Everybody, just in, DVD hack, now playing DVD while car is in motion!! I am so psyched!! I wanted everyone to know that I am a true Contributor to the CTS-V Community!! My brother and I where out in the car determined to find a solution. It took us about ten minutes to figure out with no wiring changes! You have to image the look on each other faces when we know we got it to work. When I released the parking break and the screen stayed on we were driving!! I also want to give crate to eyeforthectsvguy! He lead me in the right direction.

Here are the steps to be driving, riding, and watching (Be safe, if you are diving, do not watch screen!!)
  • Step 1 Put in DVD.
  • Step 2 Play DVD (Do not leave it at the front menu, if you do not start the DVD you will not be able to start it after you begin to drive.)
  • Step 3 While playing - Hold the ‘forward seek’ button then hit the second from the bottom buttons on the right hand side of the DVD screen. (You will see a little flicker) (picture to follow- ed)
  • Step 4 Now disable the parking break and make sure that the DVD stays on.
  • Step 5 Enjoy

    If you did everything correct you will notice that all the features are disabled. If you are at the main menu of the dvd you will not be able to select play movie or any features.

    If you would like to stop the dvd, you must hit the top right button first. Then it will bring up the safety lock if you are in motion or parking break off.

    Other notes:
    I got DVD-R to play fine in mine, but the +R are having some problems.


DEALER / PERSON TRACKING USING NAVIGATION (See discussion) (back to the top)

Before you take it to the dealership disable the tracking on the navigation system. Then when you get to the dealership check your milage and re-enable the tracking.

That way, when you pick your car up you can check the map to see if it's been driven off the dealership's lot. I know this sounds paranoid but I had problems in the past with the shop guys taking my old '95 Trans Am out for joy rides whenever I would take it in for service. Complaining to the shop manager didn't do any good until one day when they hit a curb and bent a tie rod. Needless to say, that guy got his walking papers but I still hat leaving my car for service. Especially when it has 400 HP.


1.Turn the ignition to the ON (II) position. Do not start the engine.
2. Leave the ignition in the ON (II) position for atleast 3 minutes so that the electronic throttle control will cycle and re-learn its home position.
3. Turn the ignition OFF
4. Start and run the engine for atleast 30 seconds.

After the 30 seconds, you can keep running it or turn it off. Its set by then.

If you follow through with these insturctions completely- to the dot, and it still doesnt work properly then you may have a problem.

HOW TO REPROGRAM THE TIRE PRESSURE SENSOR GUAGE (See discussion) (back to the top)

The same module reads all the RF stuff on the car including both fobs and all four tire pressure sensors. If the key fobs are working but the tire pressure sensors aren't, they'll probably just need to reprogram the sensors. The module they replaced had individual codes for each of the four sensors stored in it. When you replace the module, those codes go with it and the new module has blanks in place of the codes. Simple routine if you wanna reprogram them yourself:

1) key in RUN, engine off
2) park brake set, cluster on pressure display
3) press lock and unlock on fob until you hear a horn honk
4) let air out of (or put air into) Left front tire until you hear another horn honk
5) repeat on Right Front tire
6) repeat on Right Rear tire
7) repeat on Left Rear tire
8) after left rear tire you should hear a double honk and the process is complete
9) verify the pressures on the cluster display
Note: it's easier to let air out of the tire, of course, but then you'll probably have to put some back into the tire when the process is complete. The dealer should have a tool that looks like a garage door opener that they can use in place of the air-letting procedure. It excites a mechanism inside the sensor so they don't have to fool with the air pressure. Target for every day driving pressures should be shown on a sticker on the door, I think.

Tire pressure units:
part number is: 257663677
Dealer cost is $52.00 a piece.



Working closely with GM’s new Performance Division, GM Powertrain engineers have developed the 5.7L LS6 V-8 for application in Cadillac’s highly successful CTS sedan. With GM’s most powerful passenger-car engine (and one of the world’s best sports car engines), the resulting Cadillac CTS-V delivers exceptional performance that meets or beats the best luxury-performance sedans from Europe and Japan by virtually any measure.

The CTS-V LS6 has the incredible low-end grunt, the same broad powerband and the efficient, high-rev breathing that driving enthusiasts admire in the Corvette Z06.

“The CTS-V engine is a Corvette LS6 in nearly every aspect except for the exhaust manifolds, the oil pan and the accessory drive,’’ said Dave Muscaro, assistant chief engineer for the LS1 and LS6 V-8s. “Yet Corvette is a pure sports car, with the cammy, tingling idle sports car drivers expect. The CTS-V is a luxury sedan – a Cadillac – that just happens to go like stink. Refinement is prerequisite. To address this discrepancy, development engineers created new engine mounts – called ‘focus mounts’ – for the CTS-V.”

Engine mounts serve two purposes: They hold the engine in the vehicle, and they isolate some of the engine’s inherent vibration from be transmitted through the frame or vehicle platform. Most vehicles, including the Corvette, have vibration-dampening material on the platform side of the engine mounts. The engine bolts directly to the mounts, and the mounts bolt to the frame with some type of isolating material or device. After analyzing the LS1’s center of gravity and its placement in the CTS-V platform, the development team came up with an elegant alternative. The CTS-V’s focus mounts move the dampeners – in this case, liquid-filled rubber isolators – to the engine side of the mounts. Dampening occurs closer to the LS6’s center of gravity, before engine vibration travels down the mounts to the platform. The result is vibration control appropriate for a Cadillac, with a smoother idle that barely hints at what the CTS-V has in store when the driver slams the gas pedal to the floor.

The LS6 also required a few packaging adjustments for its move from a sports car to a four-door sedan. The air box, air filter and snorkel leading to the throttle body were reworked to fit the CTS engine bay, with the new CTS-V induction plumbing drawing air nearly as efficiently as the Corvette.

The LS1’s cast nodular iron exhaust manifolds were redesigned to fit the CTS platform architecture and, at the bottom of the engine, the LS6 oil pan was reshaped to accommodate the CTS’ front suspension and steering. Like the Corvette (and unlike the Pontiac GTO), the CTS-V oil pan has a rear sump, similar to the pan of the Chevrolet Camaro and Pontiac Firebird.

Finally, the LS6’s accessory drive belt was rerouted for the CTS-V. From the front view, accessories such as the alternator and power steering pump are positioned similarly to those on the Pontiac GTO LS1, so the CTS-V belt follows a similar route. Yet viewed from the top, the belt tracks 20 mm closer to the block, at the same depth as the Corvette LS6 belt.


0-60mph test: 4.6 seconds
1/4 mile test: 13.1/107 mph
Braking 60-0 122.7 feet

According to Motor Trend:
0-60mph test: 5.1 seconds
1/4 mile test: 13.5/105.3 mph
Braking 60-0 121 feet

1/4 mile: 13.3 / 105.47

1/4 mile: 13.403 / 109.79


Bolt pattern:
The bolt pattern is 6 on 115mm. Very rare. Same as on the SRX.

Offset of the 18x8.5 wheels is 42mm.


I have done quite a bit of work on the clunk issue since I have the problem on my CTS-V. The problem comes from the soft rubber torque coupling and the drive shaft center bearing mount. Both of these parts are made with rubber that is very soft to reduce road and gear noise inside the car. The clunk occurs when the clutch is suddenly released when there is torque on the drive shaft. The large amount of torque created on the dirve shaft in low, second, and reverse twists these rubber components like a rubber band. When you push in the clutch quickly this torque is suddenly released and the rubber parts quickly unwind. GM calls this torque reversal, but it is not actually a reversal. The clunk noise actually is not made by the drive shaft. The clunk comes from the ring and pinion gear in the differential box. When the drive shaft unwinds suddenly the pinion teeth impact the ring gear teeth and you hear the noise. The noise is loudest if you stand outside near the rear wheels. The noise is comming through the axles and into the wheels, but it is all caused by the soft rubber in the drive shaft. Some of this sudden unwinding is caused by the drive shaft itself since it appears to made from aluminum. Aluminum has one third the stiffness of steel so this causes some of the problem, but I think 90% of the problem is from the rubber. I have had emails on this subject going through the Southeastern Cadillac service rep to power train engineers at GM. Here is their response:

"The CTS-V driveline has a few "normal" operating characteristics that some customers may find objectionable. Obviously this is because the driveline was designed with high speed performance and durability as the primary criteria, pleasability issues that normally rank as high Cadillac priorities were relegated lower because this car is not like other Cadillac's. We know torque reversal in the driveline will cause an audible clunk and this can occur under various common driving/clutching conditions."

"Torque reversal is a result of normal axle backlash, the driveshaft rubber isolation flanges, the center support and the dual-mass flywheel working together. This phenomenon has been thoroughly evaluated by engineering and has been validated as not detrimental to durability or high performance usage. It is normal and no repairs should be attempted."

They will not give me the e mail address or the phone number of the engineer. Please send an e mail to: (email address removed at Robert Newman's request) and complain about this problem. Mike is the service manager for the Southeast and he will forward your comments.

You can create the clunk without moving the car. Put the parking brake on. Shift to first gear. With the engine at idle (about 1000 RPM) slowly let the clutch out until the engine bogs down to about 600 RPM. The very suddenly push in the clutch and you will hear about three clunks. Do not give the engine any gas when you are doing this. Just idle speed is good enough.

I actually blocked the car up very safely and got under the car. I trained my wife to go through this procedure while I was under the car, and I could see the drive shaft clunking back and forth.

In my younger days I was a power train engineer for off highway equipment so I know something about this issue. To me it is an unacceptable defect in the design of the CTS-V. So far Cadillac will not try to correct the problem. If you complain it will help. They tell me I am the only one complaining. The solution is to make these rubber parts from higher durometer (stiffer) rubber.

Please give me a call and I can tell you even more about trying to relsove this issue. My daytime phone numbers are 803-822-7400 or 803-429-7000.


HOW DO I CLEAN THE SEATS IN MY CADILLAC CTS-V? (See discussion) (back to the top)

Leather: Damp cloth, Zymol, Meguiars Gold Class Rich Leather Foam

Suede inserts: This is not real suede. It is UltraSuede, a micro knit fabric. Cleaning: Vacuum,TBD


HOW DO I REMOVE THE DOOR PANELS ON MY CADILLAC CTS-V? (See discussion) (back to the top)

Front: On the door opening handle cover, there is a small "cutout" on the bottom toward the front - this is where you insert a tool and pry up until you hear it pop once. Then pull the door opening handle out and pry the rest of the cover off and over the handle. Next, just behind the door pull handle, there is an oval piece that you pry out, and behind it are two screws. Remove these screws. Next, starting at the bottom, pry the door panel up and it will begin to pop and then work it around until you have the panel completely pulled away from the door. Now push up and out to get it finally off the door.

The front speaker is affixed to a bracket and then to the door. In the non-bose, it's a 5.25" (5 1/4") speaker, in the bose is (reportedly) a 6.75" (6 3/4") speaker. But keep in mind that it is 2 ohm (so a 4ohm speaker will produce less volume), and in both applications it's equalized (crossed) to produce below 6000hz, so you will not get very good highs from the speaker.

The rear is removed the same, however, the speaker is screwed to the door panel, not the door. It is a 4 ohm speaker and full range.


  • You have to remove the left front pillar molding (w/ speaker)
  • Then remove the small holder that holds the visor on the right
  • Then pop the center overhead console down from the ceiling
  • Then unscrew the three screws holding the visor on.
  • Then pull down on the roof liner carefully in that front corner until you can reach inside and pry the harness connector from the roof liner (it's glued). Becareful, the roofliner is fiberglass and will give you fiberglass splinters!
  • Once you pry the connector up, you then need to manipulate the connector loose (you can only fit one arm in there)
  • Then you just plug the new visor up to the old connector, and reconnect everything.

HOW DO I CHANGE THE REAR DIFFERENTIAL FLUID ON MY CADILLAC CTS-V? (See discussion with pictures) (back to the top)

1. Items Required:

-- Two quarts of GM #12378261 GM Synthetic Axle Lubricant SAE 75W-90 (~$27/quart)
-- One 4 oz. bottle of GM #1052358 Limited Slip Axle Lubricant Additive
-- One 10-mm hex allen wrench
-- Suction gun
-- Oil drain pan
-- Set of Rhino ramps or equivalent
-- Creeper to roll under car
-- Troublelight to see in the dark
-- One CTS-V (most important part!)

2. Before the oil change, drive at least 10-15 miles at highway speeds to warm the differential.

While working under the car, the engine, transmission, differential and exhaust will be extremely hot. Be careful, safety first!

3. With the rear of the V safely supported, remove the fill plug first. The fill plug is located on the driver's side of the differential, half-way up the side of the differential housing and is a bit tricky to get at with the exhaust pipe in the way. Try using both ends of the 10-mm allen wrench to loosen the fill plug.

4. Position the oil drain pan under the differential and remove the drain plug with the 10-mm allen wrench.

Caution! Hot lubricant will come out quickly!

5. While the differential housing is draining, clean up the drain plug. Here's the "before" shot of my plug. The dark glob on the end of the magnetic plug is the metallic paste that has formed from normal bevel pinion gear break-in.

6. After the lube is done draining, install the clean magnetic drain plug and tighten snugly with the 10-mm allen wrench.

7. Remove the top of the suction gun and fill it half full with the new GM diff lube. Pour in the bottle of limited slip additive and then continue to fill the suction gun body with diff lube until near the top of the gun. Place the top of the suction gun back on, go under the V, place the hose in the fill hole and press in the handle on the suction gun to push the fluid into the diff housing.

8. Once the suction gun is empty, refill with diff lube and continue to fill the differential housing until lubricant begins to spill out of the hole.

9. Reinstall the fill plug and tighten until snug.

10. Clean up your mess, safely lower the V and take it for a spin and enjoy the knowledge that for not much money, you've done your differential a favor!


WHAT BRAKE PADS WILL WORK ON THE CADILLAC CTS-V? WHAT ARE THE SPECIFICATIONS? (See discussion with pictures) (back to the top)

Good news is, the front is an "off-the-shelf" Brembo caliper.

This caliper is also used on the Viper, Lotus Esprit, etc. It's Brembo caliper:
model# 20.5187.30
So pads are available right now!

FMSI no: D592
Thickness: 0.665

Rear (This is a V proprietary pad )
FMSI no: D1011
THickness: 0.785

Hawk is showing availablity: HB194

THe Hawk HP might be a good pad to try, it's not known to be dusty, but (guessing here) it's probably not as aggressive as the stock pads. The Hawk HP+ is a great street/track pad... works well on the track, probably just as dusty as stock pads.

WHAT STOCK TIRES SHOULD I GET FOR MY CADILLAC CTS-V? (See discussion) (back to the top)


  • Bridgestone Potenza RE050 - $201
  • Bridgestone Potenza RE050 XL - $203
  • Bridgestone Potenza RE050A (run flat) - $263
  • Bridgestone Potenza S-03 Pole Position - $224
  • Dunlop SP Sport 9000 - $201
  • Continental ContiSportContact 2 - $218
  • Goodyear Eagle F1 GS-D3 - $208
  • Michelin Pilot Sport - $246
  • Michelin Pilot Sport XL - $268
  • Michelin Pilot Sport A/S - $247
  • Pirelli PZero Rosso Asimmetrico - $215
  • Pirelli PZero System Direzionale - $216
  • Yokohama AVS ES100 - $168

    From miscreant: 1) Stay away from RE050s. They provide no appreciable increase in performance over other tires on the bunch, but WEAR OUT faster than any of them.
    2) S03s are fantastic. Wear "well" and provide a ton of grip and good wet weahter.
    3) Sport 9000s provide the least amount of grip of the group. They ride great (read: soft) but talk to you at the least amount of loss of grip.
    4) Continentals (read same as RE050s) - "Good enough for Porsche?" - yeah cause they were the lowest bidder!
    5) Gs-D3s are GREAT, except in ANY snow or ANY ice. If the road is at all slick (like oiled asphault, slight freeze, etc) they break away easy. GREAT wet tires.
    6) Pilot Sports are good tires, but pricey. Probably as good as the s03s but the s03s look better. You don't need the XL, it's Reinforced and rougher riding. The A/S are great tires (3rd time running them on a car), but they don't provide as much grip as the others. Wear better though. Kinda not quite enough tire for the CTS-V.
    7) Others, haven't owned.



If for some reason one of your keys need reprogramming because it won't start the car, do not let the dealer associate a monetary amount for doing this. The process of reprogramming your key takes about 2 minutes. The bad key has to be placed on the steering column, the good key in the ignition. Turn the ignition to start, do not crank the car, then count to 20. Reverse the keys and do the process again. This process should reset the chip in the bad key.



These represent the part numbers that are "different" than the regular CTS. Upgrade at your own risk, only posted to help you out. Can be ordered at for cheaper than dealer!

Front Facia: 12335777
(This is the main bumper cover, 1 piece)

Front Facia Extension (L&R): 25750634 and 25750635
(The front inside fender well since the front facia is longer)

Fog Lamps (L&R): 25753700 and 25753699
(these are different part numbers from the regular CTS - don't know if regular CTS ones can be retrofitted)

Front Bumper bar: 25764982
(This is behind the facia, like the fiberglass bumper)

Grille, upper: 21996486
Grille, lower: ?

Front door Side Skirts(L&R): 88980499 and 88980500
Rear door side skirts: 88980501 and 88980502




1. Key on
2. Press Nav button on left side of screen
3. Press Agree
4. Press the Big Round Button (BRB) to access the Nav menu
5. Press Stored Points
6. List will come up, #1 should say (Home)
7. Press BRB to edit
8. Enter your address...
9. When done, press the Lock button on the right side of the screen


CADILLAC'S RESPONSE TO VARIOUS COMMON ISSUES (See discussion) (back to the top)

CTS-V Unique Features Not Common with Other Cadillac Vehicles

Subject: CTS-V Unique Features Not Common with Other Cadillac Vehicles
Message #: CAS20040022
Corporate Bulletin Number 04-00-89-027 is currently available in SI.

Models: 2004–2005 Cadillac CTS-V

This bulletin is intended to inform dealers of some of the unique features and functions of this model.

Stiff Ride

Important: Ensure that the tire pressure is at 30 psi (210 kPa) for both front and rear tires.

The CTS-V has a noticeably stiffer suspension than the CTS. This may not bother the performance car enthusiast, but Cadillac loyalist and those with traditional Cadillac expectations may not find this feature appealing.

Rear Axle Hop

The independent 5-link rear suspension on the CTS-V is designed to keep the tires and wheels stuck to the road. However, in extreme loss of drive wheel traction or abusive applications of power, if the throttle is not reduced, the effects of the suspension's design to keep the tire firmly against the road surface will result in a noticeable, abrupt wheel/axle hop.

Handling in Snow

The CTS-V is equipped with P245/45WR18 Extended Mobility Tires (EMT, or run-flat). These are Goodyear F1 Supercar performance-oriented tires and provide the ultimate handling for the combination street and track environment. They are not, however, all-season tires and will not give optimum performance in mud or snow. If the CTS-V is to be driven in areas that regularly experience adverse winter conditions, snow tires of the same size on all four wheels should be considered. Never exceed the speed rating for your selected tire. Winter tires will be available in the future.

Brake Dust

Brembo high performance brake systems are on all four corners of the CTS-V. A key requirement of a high performance lining is to dissipate heat from the braking system, thus resisting fade, cooling rotors and preventing brake fluid boil. A by-product of this heat dissipation, though, is brake dust. Brake dust accumulation on wheel faces is normal and common with high performance linings.

Critical Tire Pressure Monitor

Tire pressure monitor systems are emerging on many vehicles and add additional safety and awareness regarding tire inflation. TPM was selected for the CTS-V because it uses EMT run-flat tires and does not have a spare. Specified tire pressures are critical on the CTS-V due to the window of the TPM calibration. Tires come from the factory filled at 38?psi (260?kPa) to ensure proper sealing of the bead seat and to prevent tire damage in tied-down shipping. If not adjusted to the correct 30?psi (210?kPa) tire placard specification by the dealer, the tire, when warmed up, will easily exceed the 42?psi (290?kPa) limit on the TPM and illuminate system warnings and faults to the driver. Excessive pressures will also turn an already very stiff ride into a harsh poor handling experience.

Rough Idle

The 400?horsepower LS6 V8 engine derives its awesome power through a combination of displacement, stroke and tuning. A key element of this combination is giving the engine better "breathing" ability through unique camshaft to valve lift and duration. The efficient process of getting the air/fuel mixture in and exhaust gases out of the combustion chamber is achieved through this higher valve lift and longer valve open times. The result of camshaft design results in what is commonly referred to as an unstable idle or the random roughness of the engine. This is normal and does not indicate a concern.

1-4 Skip Shift

This feature helps the driver get the best possible fuel economy. When certain parameters are met, the transmission will force the driver to perform a 1st to 4th shift, not allowing a shift to 2nd gear. The following conditions must be met in order for this to happen:

  • • the engine coolant temperature is higher than 169°F (76° C),
  • • vehicles speeds are 15-19?mph (24-31?km/h) and
  • • the throttle percentage is 21 or less

    There is a 1-4 indicator in the speedometer Driver Information Center, but it does not illuminate all of the time. It is only momentarily in presence and is usually not seen. This will be a very aggravating feature if not adequately explained to the driver.

    Brake Lining Bind After Setting

    The Brembo brake components have a tendency to a light bind, often noted as resistance, then a light clunk when attempting to move the vehicle forward or rearward after a cold soak. This is usually noticed after parking, when the brakes have been wet, as in driving in the rain or just after a car wash. This is normal and does not effect the operation or performance of the brakes.

    Driveline Clunk on Declutch in Parade Type Driving

    While driving in a steady, slow speed parade-type situation, a clunk-clunk noise from the driveline may be heard when depressing and releasing the clutch pedal or between shifts.This noise is characteristic of torque reversal of the driveline due to component architecture and is not a condition of operational concern. This noise may be slightly more noticeable on the CTS-V than the base CTS model due to rotating inertia of the large dual mass flywheel and larger diameter propshaft. This condition is normal and no repairs should be attempted.

    Oil Life System and Mobil-1 Oil

    Mobil-1 synthetic engine oil is the factory fill for the CTS-V. Oils other than Mobil-1 may be used as long as they meet GM Standard?GM4718M. Oils may be identified as synthetic but may not meet this standard. Mobil-1 meets all of the requirements. Oil life may seem shorter on the CTS-V because the OLS algorithm uses factors of engine RPM and coolant temperature cycles, both of which the CTS-V will experience in greater fluctuations. This may result in shorter intervals as compared to other Cadillac vehicles.

    Navigation But No Voice Commands

    The navigation radio system used in the CTS-V functions similarly to the unit used on the CTS, with a few exceptions. Since the steering wheel controls on the CTS-V are for the I/P DIC, traction control, and cruise control, you do not have any re-configurable controls, OnStar® interface or voice command controls. Voice command, therefore, is unavailable on the CTS-V.

    Memory Functions

    The driver 1 and 2 seat and mirror memory functions are the same as the CTS, with one exception. Because the CTS-V has a manual transmission, these functions will only work when the parking brake is set, whether the driver uses the RKE or the 1 and 2 button on the driver's door panel.

    G-Force Meter

    A lateral accelerometer display is located in the left instrument panel display, under the tachometer. It can be accessed by using the outer most rocker switch on the left steering wheel spoke. In this mode, the meter will display momentary and peak lateral acceleration. To reset the peak acceleration to zero, simply press and hold down the outer most rocker switch on the left spoke of the steering wheel while the G-force meter is displayed.


HOW-TO INSTRUCTIONS: CHANGE CADILLAC CTS-V TRANSMISSION FLUID (See discussion and pictures) (back to the top)

1. Items Required:

-- Four quarts of Dextron III Automatic Transmission Fluid (for mine I used Mobil1 ATF). -- Fluid pump (make sure the threads are big enough for the Mobil1 bottle) or a suction gun would also work well -- Oil drain pan -- Set of Rhino ramps or equivalent -- 7/8" wrench -- 3/8" ratchet -- Roll of teflon tape -- Creeper to roll under car -- Troublelight to see in the dark -- One CTS-V (most important part!)

2. Before the oil change, drive at least 10-15 miles to warm the transmission fluid up to at least 150 degrees.
NOTE: While working under the car, the engine, transmission and exhaust will be extremely hot. Be careful, safety first!

3. With the V safely supported, remove the fill plug on the driver's side of the transmission with the 3/8" ratchet. The fill plug is half-way up the side of the transmission, near the orange "Use Dextron III ATF Only" sticker and CAGS harness.

4. On the passenger side of the V, locate the transmission temperature sensor. It is located on the RH side at the lower rear of the transmission. Disconnect the transmission temperature sensor harness and place the end of the harness behind the transmission's serial number tag to prevent the harness from being melted on the hot exhaust pipe.

5. Slide the oil drain pan under the V and with the 7/8" wrench, remove the temperature sensor.
NOTE: Caution! Hot oil will come out quickly and also splash on the passenger side exhaust pipe!

6. While the fluid is draining, clean up the temperature sensor.

7. Apply several wraps of teflon tape around the threads of the sensor. Make sure to wrap it the correct direction. Suggest holding the tape in your left hand, the sensor in your right. Place the tape on top of the sensor threads and rotate the sensor clockwise with your right hand. This will put the tape on in the same direction as the threads are cut.

8. Once the fluid is done draining, clean up the transmission of any fluid that may have dripped out around the hole.

9. Thread in the temperature sensor and tighten until it is just snug with the 7/8" wrench.

10. Reconnect the temperature sensor harness.

11. Clean the fill plug and wrap with teflon tape, similar to step 7.

12. Use a fluid pump (or a suction gun) to pump the fluid into the fill hole on the driver's side.

13. Fill the transmission more slowly when you get about half way through your 4th quart of fluid. Continue to fill until fluid begins to run out of the fill hole. Here's the puddle of fluid I had on the floor after "knowing" it was full.

14. Insert the plug and tighten until just snug with the 3/8" ratchet.

15. Clean up your mess, safely lower the V and take it for a spin and enjoy the knowledge that for not much money, you've done your transmission a favor! V

16. Here's the comparison in color between the factory fill and the Mobil1. Hate to see what this would look like after 100,000 miles since GM says it is "filled for life."

FWIW, the technical specialists / guru's on the Z6 forum advise waiting until 5000 miles before switching to *synthetic* tranny fluid, to make sure the syncho's are fully broken-in.
here are some Fluid Specifications:

Also: And here is a "zoomed-out" pic showing both fill (above Dextron III sticker) and drain plugs (lower right of pic). Note the exposed threads on the plugs (factory orange thread compound)... as posted, "tighten until snug"... no need to waste on the plugs.


HOW-TO INSTRUCTIONS: CADILLAC CTS-V DIFFERENTIAL LUBE CHANGE (See discussion and pictures) (back to the top)

  • 1. Items Required:
  • -- Two quarts of GM #12378261 GM Synthetic Axle Lubricant SAE 75W-90 (~$27/quart)
  • -- One 4 oz. bottle of GM #1052358 Limited Slip Axle Lubricant Additive
  • -- One 10-mm hex allen wrench
  • -- Suction gun
  • -- Oil drain pan
  • -- Set of Rhino ramps or equivalent
  • -- Creeper to roll under car
  • -- Troublelight to see in the dark
  • -- One CTS-V (most important part!)

  • 2. Before the oil change, drive at least 10-15 miles at highway speeds to warm the differential.
    While working under the car, the engine, transmission, differential and exhaust will be extremely hot. Be careful, safety first!

  • 3. With the rear of the V safely supported, remove the fill plug first. The fill plug is located on the driver's side of the differential, half-way up the side of the differential housing and is a bit tricky to get at with the exhaust pipe in the way. Try using both ends of the 10-mm allen wrench to loosen the fill plug.

  • 4. Position the oil drain pan under the differential and remove the drain plug with the 10-mm allen wrench.
    Caution! Hot lubricant will come out quickly!

  • 5. While the differential housing is draining, clean up the drain plug. Here's the "before" shot of my plug. The dark glob on the end of the magnetic plug is the metallic paste that has formed from normal bevel pinion gear break-in.

  • 6. After the lube is done draining, install the clean magnetic drain plug and tighten snugly with the 10-mm allen wrench.

  • 7. Remove the top of the suction gun and fill it half full with the new GM diff lube. Pour in the bottle of limited slip additive and then continue to fill the suction gun body with diff lube until near the top of the gun. Place the top of the suction gun back on, go under the V, place the hose in the fill hole and press in the handle on the suction gun to push the fluid into the diff housing.
  • 8. Once the suction gun is empty, refill with diff lube and continue to fill the differential housing until lubricant begins to spill out of the hole.
  • 9. Reinstall the fill plug and tighten until snug.

  • 10. Clean up your mess, safely lower the V and take it for a spin and enjoy the knowledge that for not much money, you've done your differential a favor!




Change your oil when the oil life monitor tells you it's necessary. You will need 7* quarts of your favorite flavor of oil. Delco PF-46 Filter or a filter on this list Click Here Drain plug (rubber) washer (if you need the part# for this I can go look it up)

1. Open hood, and open engine oil filler cap, raise car (prefer warm to hot oil).
2. Using a box wrench (no I don't even recall what size), open the oil drain plug, allow all the oil to drain into a proper oil recyling container.
3. Remove filter (may require some basic oil filter removal tool) - beware more oil coming out here.
4. Replace with fresh filter with the top O ring oiled sufficently. Tighten.
5. Clean off metal shavings from oil drain plug and replace rubber washer
6. Reinstall Drain plug - tight.
7. Clean off any oil that has splashed/spilled or otherwise come into contact with the underbody, oil pan or floor.
8. Lower car and pour in 5 OR 6 quarts of oil. Try not to spill any.
9. Start the car, while monitoring oil pressure in the DIC. You should see an oil warning, since for a few moments there is not enough oil in circulation. This should go away in a few seconds. Shut off the car.
10. Check oil level and add to full if necessary. Mine took about 6.25 quarts. Replace filler cap, close hood.
11. Reset Oil life in NAV/DIC by (with car running) going to INFO>Oil Life>RESET (Press and HOLD until XXX turns to 100%)
12. DRIVE, Enjoy, DRIVE, Enjoy, DRIVE, Enjoy

Note: It does not take 7 quarts. It takes a bit more than 6 - so you need 7 bottles for the fill-up.

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