Buick  Lacrosse 2005-2008
 PART   COLOR  LOCATION
 12 VOLT CONSTANT   RED (+)   @ BATTERY or FUSE BOX
 STARTER  YELLOW (+)  IGNITION SWITCH HARNESS or BCM, C1, Pin 21 See NOTE #2
 STARTER 2  N/A  
 IGNITION 1  PINK (+)  IGNITION SWITCH HARNESS or BCM, C1, Pin 22 See NOTE *1
 IGNITION 2  N/A  
 IGNITION 3  N/A  
 ACCESSORY/HEATER BLOWER 1  BROWN (+)  IGNITION SWITCH HARNESS or BCM, C1 Pin 23 See NOTE #2
 ACCESSORY/HEATER BLOWER 2  N/A  
 KEYSENSE  N/A  
 PARKING LIGHTS ( - )  BROWN/WHITE (-)  @ BCM, C3 Pin 8, See NOTE #2
 PARKING LIGHTS ( + )  BROWN (+)  @ FUSE BOX or PASSENGER KICK PANEL, Harness to REAR of VEHICLE.
 POWER LOCK  RED/BLACK (TYPE B)  @ BCM, C2 Pin 2, See NOTE #2
 POWER UNLOCK  ORANGE/BLACK (TYPE B)  @ BCM, C2 Pin 11, See NOTE #2
 DOOR TRIGGER  See NOTE #3  @ BCM, C2, See NOTE #2
 DOMELIGHT SUPERVISION  GRAY/BLACK (-)  @ BCM, C1 Pin 43, See NOTE #2
 TRUNK RELEASE  LIGHT BLUE (+)  @ BCM, C2, Pin 45, See NOTE #2
 SLIDING POWER DOOR  N/A  
 HORN  BLACK (-)  @ BCM, C1 Pin 4, See NOTE #2
 TACH  ANY wire NOT PINK or WHITE (AC)  @ ANY FUEL-INJECTOR
 WAIT TO START LIGHT  N/A  
 BRAKE  WHITE (+)  @ BCM, C2 Pin 30, See NOTE #2
 FACTORY ALARM DISARM   PURPLE (-)  @ BCM, C2 Pin 24, See NOTE #2
 ANTI-THEFT  GM'S TRANSPONDER ANTI-THEFT SYSTEM, See NOTE #1  @ IGNITION SWITCH TUMBLER
 EXTRA INFORMATION
 NOTE #1: This vehicle is equipped with GM's TRANSPONDER ANTI-THEFT System and will require part #791 BYPASS MODULE and an extra ignition key for Remote Starter Operation. To order go to the SECURITY BYPASS MODULE Page on this website. NOTE #2: the BCM is located to the LEFT of the STEERING COLUMN, C1 is a BLACK 52-Pin plug, C2 is a BLACK 52-Pin plug, and C3 is a BLACK 18-Pin plug. NOTE #3: the DRIVERS DOOR is a GREY/BLACK (-) Pin 26, the PASSENGER DOOR is a BLACK/WHITE (-) Pin 17, the DRIVERS REAR DOOR is a BLUE/BLACK (-) Pin 7 and the PASSENGER REAR DOOR is a LIGHT GREEN/BLACK (-) Pin 5 when connecting to an Alarm System use all 4 wires and DIODE ISOLATE, See DAIGRAM