Found this on a site aimed at installers. I take no responsibility for the accuracy of this info - test everything! I also found links to all kinds of adapters for interfacing remote starters and alarms with the GM databuss, passlock, and so on.

| ITEM | WIRE COLOR |POL| WIRE LOCATION |
| 12V|red & red/white |+ |ignition harness |
| STARTER|yellow |+ |ignition harness |
| IGNITION|pink |+ |ignition harness |
| SECOND IGNITION|white |+ |ignition harness |
| ACCESSORY|orange |+ |ignition harness |
| SECOND ACCESSORY|brown |+ |ignition harness |
| POWER LOCK|white |- |switch on right rear panel |
| POWER UNLOCK|lt. blue |- |switch on right rear panel |
| LOCK MOTOR|gray | |driver door module in door |
| UNLOCK MOTOR|tan | |driver door module in door |
| DISARM DEFEAT|tan | |driver rear door harness |
| PARKING LIGHTS +|brown | |driver kick panel |
| PARKING LIGHTS -|gray/black | |headlight switch |
| HEADLIGHTS|pink or white |- |headlight switch |
| DOOR TRIGGER|*1 |- |*1 |
| DOME SUPERVISION|comes on with disarm| | |
| TRUNK/HATCH PIN|pink/black |- |harness to BCM *2 |
| HOOD PIN| | | |
|TRNK/HTCH RELEASE| | | |
| FCTRY ALARM ARM| | | |
|FCTRY ALRM DISARM|lt. green |- |driver door module in door |
| TACHOMETER|NOT pink | |any fuel injector |
| SPEED SENSE|green/white | |pin 50, grn plug @ PCM *3 |
| BRAKE WIRE|white |+ |brake pedal switch |
| HORN TRIGGER|black or blk/yel |- |column or gray plug @ BCM *2|
| WIPERS| | | |
| LF WINDOW UP/DN|blue - brown |A |LF window switch in door |
| RF WINDOW UP/DN|lt. blue - tan |A |RF window switch in door |
| LR WINDOW UP/DN|blue - brown |A |LR window switch in door |
| RR WINDOW UP/DN|blue - brown |A |RR window switch in door |


Notes:
NOTE: This vehicle has the passlock II immobilizer system that, when adding a remote start, must be interfaced with. *1 The driver door trigger is gray/black at the driver door module in the door. The RF door trigger is black/white at the passenger door module in the door. The LR door trigger is lt. blue/black and the RR is lt. green/black, they are in a harness in front of the fusebox leading to the BCM rear plug. Use all four wires and diode isolate each. *2 The BCM (Body Control Module) is located behind the headlight switch. *3 The PCM (Powertrain Control Module) is under the hood on the driver side.

Found this on a site aimed at installers. I take no responsibility for the accuracy of this info - test everything! I also found links to all kinds of adapters for interfacing remote starters and alarms with the GM databuss, passlock, and so on.

| ITEM | WIRE COLOR |POL| WIRE LOCATION |
| 12V|red & red/white |+ |ignition harness |
| STARTER|yellow |+ |ignition harness |
| IGNITION|pink |+ |ignition harness |
| SECOND IGNITION|white |+ |ignition harness |
| ACCESSORY|orange |+ |ignition harness |
| SECOND ACCESSORY|brown |+ |ignition harness |
| POWER LOCK|white |- |switch on right rear panel |
| POWER UNLOCK|lt. blue |- |switch on right rear panel |
| LOCK MOTOR|gray | |driver door module in door |
| UNLOCK MOTOR|tan | |driver door module in door |
| DISARM DEFEAT|tan | |driver rear door harness |
| PARKING LIGHTS +|brown | |driver kick panel |
| PARKING LIGHTS -|gray/black | |headlight switch |
| HEADLIGHTS|pink or white |- |headlight switch |
| DOOR TRIGGER|*1 |- |*1 |
| DOME SUPERVISION|comes on with disarm| | |
| TRUNK/HATCH PIN|pink/black |- |harness to BCM *2 |
| HOOD PIN| | | |
|TRNK/HTCH RELEASE| | | |
| FCTRY ALARM ARM| | | |
|FCTRY ALRM DISARM|lt. green |- |driver door module in door |
| TACHOMETER|NOT pink | |any fuel injector |
| SPEED SENSE|green/white | |pin 50, grn plug @ PCM *3 |
| BRAKE WIRE|white |+ |brake pedal switch |
| HORN TRIGGER|black or blk/yel |- |column or gray plug @ BCM *2|
| WIPERS| | | |
| LF WINDOW UP/DN|blue - brown |A |LF window switch in door |
| RF WINDOW UP/DN|lt. blue - tan |A |RF window switch in door |
| LR WINDOW UP/DN|blue - brown |A |LR window switch in door |
| RR WINDOW UP/DN|blue - brown |A |RR window switch in door |


Notes:
NOTE: This vehicle has the passlock II immobilizer system that, when adding a remote start, must be interfaced with. *1 The driver door trigger is gray/black at the driver door module in the door. The RF door trigger is black/white at the passenger door module in the door. The LR door trigger is lt. blue/black and the RR is lt. green/black, they are in a harness in front of the fusebox leading to the BCM rear plug. Use all four wires and diode isolate each. *2 The BCM (Body Control Module) is located behind the headlight switch. *3 The PCM (Powertrain Control Module) is under the hood on the driver side.