: 2000 cadillac sts completely stumped, tried everything and new to fourm.

05-09-11, 06:16 PM
The vehicle is a 2000 sts with 190k. Up until a few weeks ago it was it was running fine. It all started with the upper radiotor hose blowing. Fixed the hose and noticed the car ran real sluggish. Thought maybe the coolant got into to something or a sensor. The ses light did flash once while this has all happened. hooked up a computer and got the p0300 error code. I need to say that the car does not run sluggish all the time, its very random. So this is what I have to done so far to try and illemniate dealership cost. I replaced boots, plugs and coild packs. Still performed the same way so I returned the coild packs to save 500$. The I went to the egr valve and cleanded it. It did have quite a bit up build up and I did get it to stick once but it wasnt concistnent.With some cleaning with break cleaner it seemed to close n open freely. this is the only thing I am unsure of in my processes. Next sprayed carb cleaner around the throttle body plenum, no idle bouncing and no increase, steady idle. Checked the PCV valve for rattle and looked at boot for cracks as well in the PCV tube. Looks clean and intact. I hooked up my ohm reader to all my fuel injectors and all were reading 15 and all seemed to have a ticking as i was using my finger, no scope. Fuel filter changed, air filter changed and all boots snug and in place. I had the air intake cleaned, surpetene belt, and oil changed prior to the hose exploding. I hooked up fuel pressure gage and levels were fine. No fule in the relay. I did it hook it up to a diff computer and got the shift sensor code as well. The tranny has never slipped or shifted hard ever and doesn't do it even with the loss of power. It does seem to shake as well when stopping. I had the front end looked at to make sure it wasn't in the suspension. Please guys any help would be appreciated and I also appoligize if I posted this in the wrong spot. All fluids are clean and topped off. Thanks guys for any help.

05-09-11, 06:29 PM
It only shakes when the motor is acting up.

05-09-11, 07:06 PM
:highfive: Welcome Aboard !!!

The car has a Northstar engine, so you're OK in here...........

Go up to the top few posts on this main page and open the one titled "How to pull codes" - your car has its own built in code reader/scanner/memory. Practice, then write down any codes found, noting whether each is Current or History. Now go back to the sticky and open the link with "obd2' in the address. This will take you to a Master Index of code definitions - all P,B,C, and U codes. Write down all the codes and definitions, come back and post it all here.

Otherwise, you MAY have a wet CKP (CranKshaft Position sensor) connector (one of two) down on the front of the engine, next to the oil filter adapter - this would screw up timing signals. Not likely, but a thought..........

Just exactly where did the coolant blow onto the engine - or did it go everywhere.......the EBTCM (Electronic Brake & Traction Control Module), on the driver's side below the air filter box - can also be a problem if saturated with coolant.

05-09-11, 07:39 PM
submariner409 Thanks for the input. Will post shortyl.

05-09-11, 08:28 PM
Okay first let me start by saying when the hose blew it seems that most was on the hood cloth (underside obviously) and there was some through out the motor. i did try to rinse most of it of with ligh water, nothing crazy, mostly just on the belts. Now for the codes. I'm going to list current as I would assume the history ones were from fixed issues. If I'm wrong let me know and I'll post thoses to.
ABS C1246
PCM P0741
PCM P1860
RSS C0620
RSS C0625
RSS C0630
RSS C0662

05-09-11, 08:36 PM
Post current and history (list which are current vs history) and in the future, list their definitions as well. There's a link in the sticky you read with code definitions.

05-09-11, 08:49 PM
C1246- brake lining wear circuit open
P0741- TCC system stuck off
P1860- TCC PWM Solenoid Circuit Electrical
C0620- Right Front Position Sensor Malfunction
C0625- Left Rear Position Sensor Malfunction
C0630- Right Rear Position Sensor Malfunction
C0662- Level Control Exhaust Valve Circuit Low

05-10-11, 11:20 AM
my hose blew off prior to my headgaskets going. too much cooling system pressure. than you got p0300 misfire code. due to wet plugs? now motor seems sluggish. could be several fouled plugs. just a thought.

05-10-11, 02:38 PM
Thanks MoistCabbage. Stoveguyy the hose blew because it came off the support from the plastic radiator cover. there is kind-of a track that it sits on and popped out and was rubbing on the pulley.

Here are the codes with history MoistCabbage. As the previous ones were current.

C1298 - PCM Class 2 Serial Data Link Malfunction
U1016 - Loss of Communications with PCM, Loss of Class 2 Communication with VCM
U1000 - Class 2 Communication Malfunction
B1982 - Device Power Circuit High
B1009 - EEPROM Checksum Error
B1327 - Vehicle system voltage below 9.0 volts
B2734 - Coded Key Controller Memory Failure
B2947 - Security System Sensor Power Circuit Low
B2948 - Security System Sensor Power Circuit High
B3055 - Key Not Present
C0635 - Left Front Normal Force Circuit Malfunction
C0640 - Right Front Normal Force Circuit Malfunction

Thanks again guys. If there is anything else you may need to help me figure out this problem please let me know.

05-10-11, 05:32 PM
C1246- brake lining wear circuit open
P0741- TCC system stuck off
P1860- TCC PWM Solenoid Circuit Electrical
C0620- Right Front Position Sensor Malfunction
C0625- Left Rear Position Sensor Malfunction
C0630- Right Rear Position Sensor Malfunction
C0662- Level Control Exhaust Valve Circuit Low[/QUOTE]

C1246 - The outside brake pads have a wear sensor installed. The pads wear, the sensor wears, opens an electrical circuit, the brake warning message lights on the DIC. "Change Brake Pads". You'll also need to change the sensor(s).
P0741 - P1860 - The transmission has a 4th gear converter lockup feature. This removes the last 300 rpm of slip in the converter at highway speeds. It's a murderous job to change the solenoid.
C0620, C0625 and C0630 - the suspension has height sensors attached/integral with the front struts and rear shocks. Something is wrong with the suspension control system(s). $$$$.00 per corner.
C0662 - There is a fault with the rear shock level control system - the compressor control head has a air supply/exhaust fault. Up in the RR fenderwell.

Look for ALL these faults in the 9 pages of threads in Discussions, Item Specific: Cadillac Tech Tips.

Codes: The car constantly checks itself for problems. Something goes wrong and a code sets as Current. If the code is from a safety or emissions system it will also illuminate one or more DIC lights as well as a DIC message. If the code comes and goes and does not re-appear for 3 successful ignition start-run cycles it goes to History - and after 30, 40, 50 or 100 successful start-run cycles (depending on system) during which the fault does not occur, the code disappears. Sooooo........some of your History codes come and go like clouds. Don't get hooked on "pulling codes" - you'll go crazy. I keep a log, pull codes every two months, and never clear any. They all disappear eventually - even the Current ones you fix. BUT in your case the fixes sound hideously expensive.

05-10-11, 06:53 PM
The suspension I'm aware of, going with strut master no air to save money. bought the car for 2k 2 years ago. the brake sensors i'm also aware of. I changed the brakes all around and saw the broken sensor so i'll just ignore that till next change of brakes. I will be having the shocks done at a very good price. 1500 installed. Its the random sluggish that im concered with. As with shift sensor, I heard horror stories of dealers wanting a grand to change it. The mechanic at Cadillac said sinse it just happened (thats when I first got the ses light checked) that it will be a while before i notice the car not shifting right. Today the car ran better than it ever has and tends to do this for a week then bam runs like dirt for a day or two and not constent. I'll drive it for 15 minutes and it clears up. Grrrrrrrrrrrrr