I have put together a definitive list of all the information we have on installing a double-din nav unit in the 2003-2007 Cadillac CTS while retaining the factory DIC. Included in this list are my own contributions along with the works of several other brave men who sacrificed time, expensive electronic components, and blood (from sharp metal edges) to bring you a complete integration procedure.
Physical fabrication for in-dash mounting:
Darkwingfrog Write-up: http://www.cadillacfaq.com/faq/answers/aftermarketradiodic/index.html
Cadillac CTS Sound System wiring schematics:
DIC and Base Amp: http://www.cadillacfaq.com/faq/answers/pdf/wiring.pdf
Bose Amp: http://www.cadillacfaq.com/faq/answers/pdf/bose.pdf
DIC Connector Pinout: http://www.cadillacfaq.com/faq/answers/pdf/wiring.pdf
Wiring Procedure (quick method):
I have decided to list MJS's writeup first, and separate from my own because it occurred to me that there may be users out there who would like to make their install as simple as possible, foregoing all the extra work necessary to make every little detail work. If you are one of these people, the following method is exactly what you want. It's the quickest, easiest way to get a nav unit installed and working in the CTS.
Installing your own aftermarket head unit is VERY easy and it’s not worth paying anyone else more than $100 to do the wiring IMO. If anyone is interested here is how you install and wire a Pioneer F-Series:
1 – Splice the new head to the factory live or wire a new live if you prefer.
2 – Ground the New head.
3 – ACC (ignition) wire on the new head to brown(on mine) wire on the air-con controls.
4 – Audio – Strip the factory audio harness back a little. Cut the factory audio wires about 3 inches from the plug, this leaves plenty of wire to rewire the factory head later if required. Take a good quality shielded RCA cable (monster or equivalent) cut about 18” off each end and strip back the wire until you have +/- wires. Take the RCA wires and carefully splice them to the harness end of the factory audio wire ( green, green, dark green and tan). It is important to get a really clean and shielded join because the RCA/audio cables pick up the old factory radio if the connections aren’t really good. Now plug the RCA cable to your new head.
Now re-install everything but don’t plug the old audio plug into the factory head. Your audio now has two gains, the factory controls and the new heads volume control. I leave my Pioneer on maximum and control the volume with the steering wheel dial.
Still works:
DIC
OnStar (all controls)
Chimes
Both factory volume controls (dash and steering wheel)
Steering wheel buttons.
Factory AMP, speakers and SUB.
You Lose:
XM (an aftermarket add-on is only $75)
New head goes off with ignition NOT by opening the door. Not a problem for me because we rarely sit in a car without the engine on in Florida. You can probably get the RAP working but it is not an issue for me so I am not going to try.
I would like to add that although the factory steering wheel controls do work, it is important to note that only the volume knob and mute button actually control the new nav unit. The "1, 2, 3, 4" buttons will now only control the HVAC and DIC functions.
Wiring Procedure (complete method):
This is my own write-up, however to get to this point I had lots of help. MJS, Kingoftypos, and Gaetano all contributed in some way to the information contained in this procedure.
For this method, you will need the following items:
- PAC steering wheel control adapter (ex: SWI-PS for Pioneer and Sony units)
- PAC OS-2CTS integration adapter (you can omit this if you want to use the ACC key position to signal the unit instead of having Retained Accessory Power)
- 2006-07 CTS-V steering wheel control set (harness not needed)
- 18AWG stranded wire (red, black, yellow)
- 22AWG stranded wire (orange, purple)
- Precision soldering iron
You have two options for giving your unit a turn-on signal (the wire usually marked ACC on aftermarket unit harnesses): The PAC OS-2CTS integration adapter, or the ACC (brown) wire in the CTS ignition harness.
PAC Integration Adapter
This device interfaces with the GM CANbus to facilitate Retained Accesory Power (unit will remain on with all car electronics for up to ten minutes after the ignition is turned off, or driver/passenger door is opened).
MAKE SURE YOU HAVE THE OS-2CTS WIRING DIAGRAM HANDY, AND STUDY IT WELL BEFORE YOU EVEN START THIS PROCEDURE!!
http://archive.pac-audio.com/instructions/os-2cts.pdf
ALSO, MAKE SURE YOU HAVE THE CTS CONNECTOR PINOUT DIAGRAMS HANDY, AND STUDY THEM WELL BEFORE YOU EVEN START THIS PROCEDURE!!
http://www.cadillacfaq.com/faq/answe...connectors.pdf
STEP 1: take the RAD-18 harness from the OS-2CTS and the harness(es) from your aftermarket unit and attach wires color-for-color. The RAD-18 is industry standard color-coded, so this part couldn't be simpler. Make sure you wire all four speakers, antenna, amp turn on, illumination, +12v constant, +12v ACC, and ground.
STEP 2: take the OS-CTS harness (has two plastic connectors on the vehicle side, one black, one red), and cut off both the red and black connectors. Wire according to the diagram on the following page.
With this adapter wired, you will be able to plug in your aftermarket unit and power it up.
Alternate Option - Omitting PAC OS-2CTS adapter
If you do not care to have functioning RAP or OnStar, you may omit the OS-2CTS adapter altogether.
Wire according to below diagram:
Turn on (ACC) power - In this case you will use the ACC wire off the CTS ignition harness (found under the steering column inside the driver's lower-dash kick panel. The panel is removed with three screws all the way at the bottom and three metal/plastic clips at the top. You can simply tap into the brown wire coming off the ignition harness (TAP, DO NOT CUT!) to supply turn-on power to your unit. The picture below shows (a blurry version of) this wire.
Illumination - There are several places to get the illumination signal from. The orange wire coming off the turn signal stalk harness is one. If anyone knows of a better wire, let me know and I will add it here.
Steering wheel controls
The simplest way to do the install is to leave the factory steering wheel controls connected as they come, to the DIC. However this means that you cannot program the 1,2,3,4 buttons as track/folder/disc advance. Basically you only have volume and mute. You can purchase a PAC translator and use it with the factory controls, but then you can't use the volume knob. You would have to program two of the 1,2,3,4 buttons as volume, and the other two as track advance. Then you have a dead volume knob and mute button. The solution? CTS-V controls. Swap a set of CTS-V steering wheel controls onto the steering wheel. To do this you will have to completely rewire the factory steering wheel harness (wires behind airbag in wheel).
Use the below wiring diagram for rewiring the stock CTS harness for the CTS-V controls.
Physical fabrication for in-dash mounting:
Darkwingfrog Write-up: http://www.cadillacfaq.com/faq/answers/aftermarketradiodic/index.html
Cadillac CTS Sound System wiring schematics:
DIC and Base Amp: http://www.cadillacfaq.com/faq/answers/pdf/wiring.pdf
Bose Amp: http://www.cadillacfaq.com/faq/answers/pdf/bose.pdf
DIC Connector Pinout: http://www.cadillacfaq.com/faq/answers/pdf/wiring.pdf
Wiring Procedure (quick method):
I have decided to list MJS's writeup first, and separate from my own because it occurred to me that there may be users out there who would like to make their install as simple as possible, foregoing all the extra work necessary to make every little detail work. If you are one of these people, the following method is exactly what you want. It's the quickest, easiest way to get a nav unit installed and working in the CTS.
Installing your own aftermarket head unit is VERY easy and it’s not worth paying anyone else more than $100 to do the wiring IMO. If anyone is interested here is how you install and wire a Pioneer F-Series:
1 – Splice the new head to the factory live or wire a new live if you prefer.
2 – Ground the New head.
3 – ACC (ignition) wire on the new head to brown(on mine) wire on the air-con controls.
4 – Audio – Strip the factory audio harness back a little. Cut the factory audio wires about 3 inches from the plug, this leaves plenty of wire to rewire the factory head later if required. Take a good quality shielded RCA cable (monster or equivalent) cut about 18” off each end and strip back the wire until you have +/- wires. Take the RCA wires and carefully splice them to the harness end of the factory audio wire ( green, green, dark green and tan). It is important to get a really clean and shielded join because the RCA/audio cables pick up the old factory radio if the connections aren’t really good. Now plug the RCA cable to your new head.
Now re-install everything but don’t plug the old audio plug into the factory head. Your audio now has two gains, the factory controls and the new heads volume control. I leave my Pioneer on maximum and control the volume with the steering wheel dial.
Still works:
DIC
OnStar (all controls)
Chimes
Both factory volume controls (dash and steering wheel)
Steering wheel buttons.
Factory AMP, speakers and SUB.
You Lose:
XM (an aftermarket add-on is only $75)
New head goes off with ignition NOT by opening the door. Not a problem for me because we rarely sit in a car without the engine on in Florida. You can probably get the RAP working but it is not an issue for me so I am not going to try.
I would like to add that although the factory steering wheel controls do work, it is important to note that only the volume knob and mute button actually control the new nav unit. The "1, 2, 3, 4" buttons will now only control the HVAC and DIC functions.
Wiring Procedure (complete method):
This is my own write-up, however to get to this point I had lots of help. MJS, Kingoftypos, and Gaetano all contributed in some way to the information contained in this procedure.
For this method, you will need the following items:
- PAC steering wheel control adapter (ex: SWI-PS for Pioneer and Sony units)
- PAC OS-2CTS integration adapter (you can omit this if you want to use the ACC key position to signal the unit instead of having Retained Accessory Power)
- 2006-07 CTS-V steering wheel control set (harness not needed)
- 18AWG stranded wire (red, black, yellow)
- 22AWG stranded wire (orange, purple)
- Precision soldering iron
You have two options for giving your unit a turn-on signal (the wire usually marked ACC on aftermarket unit harnesses): The PAC OS-2CTS integration adapter, or the ACC (brown) wire in the CTS ignition harness.
PAC Integration Adapter
This device interfaces with the GM CANbus to facilitate Retained Accesory Power (unit will remain on with all car electronics for up to ten minutes after the ignition is turned off, or driver/passenger door is opened).
MAKE SURE YOU HAVE THE OS-2CTS WIRING DIAGRAM HANDY, AND STUDY IT WELL BEFORE YOU EVEN START THIS PROCEDURE!!
http://archive.pac-audio.com/instructions/os-2cts.pdf
ALSO, MAKE SURE YOU HAVE THE CTS CONNECTOR PINOUT DIAGRAMS HANDY, AND STUDY THEM WELL BEFORE YOU EVEN START THIS PROCEDURE!!
http://www.cadillacfaq.com/faq/answe...connectors.pdf
STEP 1: take the RAD-18 harness from the OS-2CTS and the harness(es) from your aftermarket unit and attach wires color-for-color. The RAD-18 is industry standard color-coded, so this part couldn't be simpler. Make sure you wire all four speakers, antenna, amp turn on, illumination, +12v constant, +12v ACC, and ground.
STEP 2: take the OS-CTS harness (has two plastic connectors on the vehicle side, one black, one red), and cut off both the red and black connectors. Wire according to the diagram on the following page.
With this adapter wired, you will be able to plug in your aftermarket unit and power it up.
Alternate Option - Omitting PAC OS-2CTS adapter
If you do not care to have functioning RAP or OnStar, you may omit the OS-2CTS adapter altogether.
Wire according to below diagram:
Turn on (ACC) power - In this case you will use the ACC wire off the CTS ignition harness (found under the steering column inside the driver's lower-dash kick panel. The panel is removed with three screws all the way at the bottom and three metal/plastic clips at the top. You can simply tap into the brown wire coming off the ignition harness (TAP, DO NOT CUT!) to supply turn-on power to your unit. The picture below shows (a blurry version of) this wire.
Illumination - There are several places to get the illumination signal from. The orange wire coming off the turn signal stalk harness is one. If anyone knows of a better wire, let me know and I will add it here.
Steering wheel controls
The simplest way to do the install is to leave the factory steering wheel controls connected as they come, to the DIC. However this means that you cannot program the 1,2,3,4 buttons as track/folder/disc advance. Basically you only have volume and mute. You can purchase a PAC translator and use it with the factory controls, but then you can't use the volume knob. You would have to program two of the 1,2,3,4 buttons as volume, and the other two as track advance. Then you have a dead volume knob and mute button. The solution? CTS-V controls. Swap a set of CTS-V steering wheel controls onto the steering wheel. To do this you will have to completely rewire the factory steering wheel harness (wires behind airbag in wheel).
Use the below wiring diagram for rewiring the stock CTS harness for the CTS-V controls.