Buick LaCrosse II (2009-2013) (bottom of "a" pillar) Wiring diagrams

A/C COMPRESSOR SOLENOID VALVE AIR QUALITY SENSOR (BELOW AIR INLET GRILL PANEL) BLK WIRE BLK/DK BLU WIRE BLOWER MTR SPD CTRL BRN/VIO WIRE BRN/YEL WIRE COMPUTER DATA LINES SYSTEM COOLING FAN LOW SPEED RELAY DEFOGGER SYSTEM DK BLU WIRE DK BLU/LT GRN WIRE FUSE GRN WIRE GRN/YEL WIRE GRY WIRE GRY/DK BLU WIRE GRY/LT GRN WIRE HOT AT ALL TIMES HOT W/ ENGINE CONTROLS IGNITION RELAY ENERGIZED HOT W/ IGNITION MAIN RELAY ENERGIZED HUMIDITY SENS SIG TWILIGHT SENTINEL DELAY SIG HVAC CONTROL MODULE INSIDE AIR TEMP SENS LOW REF REAR DEFOG RLY CTRL LEFT COOLING FAN HIGH SPEED RELAY LINEAR INTERCONNECT NETWORK BUS 9 LOGIC LT GRN DK BLU/ WIRE LT GRN/VIO WIRE RED/VIO WIRE RED/WHT WIRE RIGHT COOLING FAN HIGH SPEED RELAY SOLAR SENS DRV SIG TEMP SENS LOW REF UNDERHOOD FUSE BLOCK (LEFT SIDE OF BATTERY) VIO/BLK WIRE VIO/GRY WIRE VIO/WHT WIRE WHT WIRE WHT/DK BLU WIRE YEL WIRE YEL/DK BLU WIRE YEL/RED WIRE

11 12 IG MODE SW CTRL LOW REF 21 20 W/ KEYLESS ENGINE START 3 4 PPL PPL ACC VOLT RUN/CRANK 1 VOLT 307 3287 HEADLIGHTS SYSTEM HORNS SYSTEM 664 94 EXTERIOR LIGHTS SYSTEM WIPER/WASHER SYSTEM ACC IND ACCESSORY LED SIGNAL LIGHTING CONTROL SW SIG AMBIENT LIGHT SENSOR SIGNAL SW SIG PPL ANTI-THEFT SYSTEM HEADLIGHTS SYSTEM BLK WIRE BLK/BRN WIRE BRAKE APPLY SENSOR SIGNAL LED BACKLIGHT DIMMING CTRL BRN WIRE COMPUTER DATA LINES SYSTEM CRUISE CONTROL SYSTEM CRUISE CONTROL SYSTEM INTERIOR LIGHTS SYSTEM DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DOOR LOCKS SYSTEM DOOR LOCKS SYSTEM EXTERIOR LIGHTS SYSTEM DOOR LOCKS SYSTEM DRIVER DR LK SW LOCK SIG FUSE FUSE (LOWER LEFT SIDE OF DASH) FUSE FUSE FUSE FUSE FUSE GRN WIRE GRN/GRY WIRE GRN/PPL WIRE GRY WIRE GRY/LT GRN WIRE GRY/WHT WIRE HDLP SW FLASH TO PASS SIG HORN SWITCH SIGNAL HEADLAMP OFF SIG HEADLAMP SW ON SIG HAZARD LED DIMMING SIGNAL HEADLIGHTS SYSTEM HEADLIGHTS SYSTEM EXTERIOR LIGHTS SYSTEM HEADLIGHTS SYSTEM TRANSMISSIONS SYSTEM HOT AT ALL TIMES IGNITION KEY RESISTOR SIG IGNITION MODE SWITCH INSTRUMENT PANEL FUSE BLOCK INTERIOR LAMP DEFEAT SW SIG KEYLESS ENTRY CONTROL MODULE (RIGHT KICK PANEL) LT GRN WIRE LT GRN/WHT WIRE LT GRN/YEL WIRE NAVIGATION SYSTEM OFF/RUN/CRANK VOLT PPL HAZARD SW TURN RIGHT SIG WINDSHIELD WASHER SW SIG PPL PPL PPL PPL 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 PPL PPL W/O KEYLESS ENGINE START RED WIRE RED/BLK WIRE RED/BRN WIRE RED/LT GRN WIRE RED/VIO WIRE RED/WHT WIRE SHIFT INTERLOCK SYSTEM SOUND SYSTEMS START IND UNDERHOOD FUSE BLOCK (LEFT SIDE OF BATTERY) VIO WIRE VIO/BLK WIRE VIO/YEL WIRE WHT WIRE WINDSHIELD WIPER SW HI SIG WIPER/WASHER SYSTEM YEL WIRE YEL/LT GRN WIRE

A/C COMPRESSOR SOLENOID VALVE A/C LOW REF A/C REFRIGERANT PRESSURE SENSOR (FRONT OF ENGINE COMPT, MOUNTED TO CONDENSER) A/C SENS SIG BATT+ VOLT BLK WIRE BLK/BRN WIRE BLK/WHT WIRE BRN/RED WIRE COMPUTER DATA LINES SYSTEM DATA DK BLU WIRE DK BLU/LT GRN WIRE ELECTRIC CTRL ELECTRIC SPLY ENGINE CONTROL MODULE (LEFT FRONT OF ENGINE COMPT) EXCEPT 3.6L 3.6L FUSE GRN WIRE HOT AT ALL TIMES HOT AT ALL TIMES INSTRUMENT PANEL FUSE BLOCK (LOWER LEFT SIDE OF DASH) HOT W/ IGNITION MAIN RELAY ENERGIZED HVAC CONTROL MODULE IGN 1 VOLT LT GRN WIRE RED/BRN WIRE RED/WHT WIRE SERIAL DATA SIG GND UNDERHOOD FUSE BLOCK (LEFT SIDE OF BATTERY) VIO/GRY WIRE WHT WIRE

10 12 HS SERIAL DATA + HS SERIAL DATA - 13 14 5 HS SERIAL DATA + HS SERIAL DATA - DATA COM ENABLE 2 4 1 3 HS SERIAL DATA + HS SERIAL DATA - HS SERIAL DATA + HS SERIAL DATA - 22 25 HS SERIAL DATA + HS SERIAL DATA - 24 23 HS SERIAL DATA - HS SERIAL DATA + 3 1 HS SERIAL DATA - HS SERIAL DATA + 30 29 28 31 HS SERIAL DATA + HS SERIAL DATA - HS SERIAL DATA - HS SERIAL DATA + 4 3 HS SERIAL DATA - HS SERIAL DATA + 42 55 41 39 40 70 HS SERIAL DATA + HS SERIAL DATA - ACCESSORY WAKEUP SERIAL DATA 7 6 17 22 21 HS SERIAL DATA + HS SERIAL DATA - 8 16 1 13 HS SERIAL DATA - HS SERIAL DATA + DATA COM ENABLE NETWORK BUS 6 BLK WIRE BLU/YEL WIRE BREAKOUT INTO TRANSMISSION CONNECTOR) CONTROL SOLENOID VALVE ASSEMBLY (ON FRONT OF TRANSFER CASE) DATA COM ENABLE DATA COM ENABLE HS SERIAL DATA + HS SERIAL DATA - DATA LINK CONNECTOR (LEFT SIDE OF DASH) DK BLU WIRE DK BLU/ WHT WIRE ELECTRONIC BRAKE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) ENGINE CONTROL MODULE (LEFT FRONT OF ENGINE COMPT) EXCEPT 2.4L 2.4L EXCEPT 3.6L 3.6L EXCEPT AWD EXCEPT AWD W/ CONTINUOUSLY VARIABLE REAL TIME DAMPING FROM BREAKOUT TO FUEL PUMP CONTROL MODULE (RIGHT REAR CORNER OF REAR COMPT) FUSE FUSE GRN WIRE GRN/PPL WIRE HOT AT ALL TIMES HS SERIAL DATA + HS SERIAL DATA + HS SERIAL DATA - HS SERIAL DATA - INSTRUMENT PANEL FUSE BLOCK (LOWER LEFT SIDE OF DASH) MULTI-AXIS ACCELERATION SENSOR (UNDER CENTER CONSOLE BETWEEN FRONT SEATS) PACK) POWER STEERING CONTROL MODULE (W/ VARIABLE EFFORT) (LOWER LEFT SIDE OF DASH) REAR DIFFERENTIAL CLUTCH CONTROL MODULE (AWD) (MOUNTED TO REAR DIFFERENTIAL) RED/DK GRN WIRE RED/WHT WIRE STEERING WHEEL ANGLE SENSOR (BASE OF STEERING COLUMN) SUSPENSION CONTROL MODULE (IF EQUIPPED) (LEFT CORNER OF REAR COMPT) TELEMATICS COMMUNICATIONS INTERFACE CONTROL MODULE (CENTER OF REAR WINDOW SHELF) VIO/YEL WIRE W/ CONTINUOUSLY VARIABLE REAL TIME DAMPING AWD W/ NON-VARIABLE RATIO POWER STEERING W/O NON-VARIABLE RATIO POWER STEERING W/O ONSTAR WHT WIRE WHT/DK BLU WIRE YEL (OR WHT) WIRE YEL WIRE YEL/BLK (DK BLU) WIRE YEL/BLK (OR DK BLU) WIRE YEL/BLK WIRE

2.4L, 3.6L 3.0L 3.0L, 3.6L 2.4L 57 51 14 15 30 34 33 53 52 54 49 15 34 25 48 47 BRK SIG IGN 1 VOLTAGE 7 13 BRAKE APPLY SENS SIG SUPPLY VOLTAGE 9 4 CRUISE CONTROL SW SIG LIGHTING CTRL SW REF ACCELERATOR PEDAL POSITION SENSOR (LEFT SIDE OF DASH) AUTOMATIC TRANSMISSION ASSEMBLY BLK WIRE BLK/BRN WIRE BLK/DK BLU WIRE BLK/VIO WIRE BLK/WHT WIRE BODY CONTROL MODULE (LEFT SIDE OF DASH) BRAKE PEDAL POSITION SENSOR (NEAR TOP OF ACCELERATOR PEDAL ASSEMBLY) BRN WIRE BRN/DK BLU WIRE BRN/LT GRN WIRE BRN/RED WIRE BRN/WHT WIRE COMPUTER DATA LINES SYSTEM CONTROL SOLENOID VALVE ASSEMBLY CRUISE IND CRUISE SWITCH CRUISE/ETC/TCC BRK SIG DK BLU WIRE DRIVER INFORMATION CENTER DISPLAY ENGINE CONTROL MODULE (LEFT FRONT OF ENGINE COMPT) FUSE GMLAN SERIAL DATA GRN WIRE GROUND GRY WIRE HEADLIGHTS SYSTEM HOT AT ALL TIMES HOT AT ALL TIMES INSTRUMENT PANEL FUSE BLOCK (LOWER LEFT FUSE SIDE OF DASH) HOT W/ IGN MAIN RELAY ENERGIZED INSTRUMENT CLUSTER LEFT STEERING WHEEL CONTROL SWITCH LOGIC LOW RE LOW REF 2 LT GRN/WHT WIRE POSITIVE VOLTAGE RED/BLK WIRE RED/WHT WIRE RES+ SENS SIG 1 LOW REF SENS SIG (2) ACTUATOR CTRL CLOSE ACTUATOR CTRL OPEN SET- SIG 1 LOW REF 1 SIG 2 SOUND SYSTEMS STEERING WHEEL AIR BAG COIL TRANSMISSION CONTROL MODULE TRANSMISSION INPUT SHAFT SPEED SENSOR TRANSMISSION OUTPUT SHAFT SPEED SENSOR UNDERHOOD FUSE BLOCK (LEFT SIDE OF BATTERY) VIO/LT GRN WIRE WHT WIRE WHT/DK BLU WIRE WHT/RED WIRE YEL (OR WHT) WIRE YEL WIRE YEL/BLK (OR DK BLU) WIRE YEL/BLK WIRE YEL/WHT WIRE

1 2 3 4 5 SERIAL DATA SERIAL DATA + SERIAL DATA + SERIAL DATA - SERIAL DATA - 1 2 GND BATTERY 3.0L 2.4L 3.6L 5 6 14 DATA + DATA - SPLY VOLT ANTI-LOCK BRAKES SYSTEM AUTOMATIC TRANSMISSION ASSEMBLY BLK WIRE BLU/YEL WIRE COMPUTER DATA LINES COMPUTER DATA LINES SYSTEM CONTROL SOLENOID VALVE ASSEMBLY DK BLU (OR YEL/BLK) WIRE DK BLU WIRE DK GRN/BRN WIRE DRIVER INFORMATION CENTER DISPLAY ELECTRONIC BRAKE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) FUSE GRN WIRE HOT AT ALL TIMES INSTRUMENT CLUSTER LOGIC LT GRN/BRN WIRE POWER STEERING CONTROL MODULE (LOWER LEFT SIDE OF DASH) RED/YEL WIRE SHAFT SPEED SENSOR STEERING ANGLE SENSOR (BASE OF STEERING COLUMN) SYSTEM TRANS- MISSION OUTPUT TRANSMISSION CONTROL MODULE (TCM) UNDERHOOD AUXILIARY FUSE BLOCK INTEGRAL TO FUSE BLOCK-UNDERHOOD) WHT (OR YEL) WIRE WHT WIRE WHT/DK BLU WIRE YEL WIRE YEL/BLK WIRE

1 2 3 4 5 6 7 8 9 10 11 12 13 14 BATTERY SOL CTRL 3.0L 2.4L 3.6L 5 6 14 DATA + DATA - SPLY VOLT ANTI-LOCK BRAKES SYSTEM AUTOMATIC TRANSMISSION ASSEMBLY BLK WIRE BLK/YEL WIRE BLU/YEL WIRE BRN/GRN WIRE BRN/LT GRN WIRE COMPUTER DATA LINES COMPUTER DATA LINES SYSTEM CONTROL SOLENOID VALVE ASSEMBLY DK BLU (OR YEL/BLK) WIRE DK BLU WIRE DK GRN/BN WIRE DRIVER INFORMATION CENTER DISPLAY ELECTRONIC BRAKE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) FUSE GRN WIRE HOT AT ALL TIMES INSTRUMENT CLUSTER LOGIC LT GRN/BRN WIRE POWER STEERING CONTROL MODULE (LOWER LEFT SIDE OF DASH) RED WIRE RED/DK BLU WIRE SERIAL DATA SERIAL DATA (-) SERIAL DATA (+) SHAFT SPEED SENSOR SOL LO REF STEERING ANGLE SENSOR (BASE OF STEERING COLUMN) SYSTEM TRANS- MISSION OUTPUT TRANSMISSION CONTROL MODULE (TCM) UNDERHOOD FUSE BLOCK (LEFT SIDE OF BATTERY) WHT (OR YEL) WIRE WHT WIRE WHT/DK BLU WIRE

12 24 HAZ SW LEFT TURN SIG HAZ SW RIGHT TURN SIG PPL 22 17 4 19 HEADLAMP SW PARK LP SIG HAZ LED DIMMING SIG B+ BRK APPLY SENS LO REF BLK WIRE BODY CONTROL MODULE (LEFT SIDE OF DASH) BRN WIRE CENTER HIGH MOUNTED STOP LAMP COMPUTER DATA LINES SYSTEM DK BLU WIRE DK BLU/VIO WIRE DK BLU/WHT WIRE DK GRN WIRE FUSE GRN WIRE GRN/YEL WIRE GRY WIRE GRY/BRN WIRE GRY/YEL WIRE HAZARD SWITCH HEAD PARK AUTO HEADLAMP SWITCH HOT AT ALL TIMES INSTRUMENT PANEL FUSE BLOCK (LOWER LEFT SIDE OF DASH) INSTRUMENT PANEL MULTI-FUNCTION SWITCH 1 LEFT FRONT SIDE MARKER LAMP LEFT LICENSE PLATE LAMP LEFT PARK/ TURN SIGNAL LAMP LEFT REAR TURN SIGNAL LAMP LEFT TAIL LAMP LEFT TAIL/ STOP LAMP LEFT REAR SIDE MARKER LAMP LT BLU WIRE LT GRN WIRE LT GRN/RED WIRE LT GRN/VIO WIRE LT GRN/WHT WIRE OFF PPL RED WIRE RED/ LT BLU WIRE RED/BRN WIRE RED/DK GRN WIRE RED/LT GRN WIRE RED/WHT WIRE RIGHT LICENSE PLATE LAMP VIO/GRY WIRE W/ HID W/O HID WHT WIRE WHT/ DK BLU WIRE WHT/YEL WIRE

BLK WIRE BRAKE PEDAL POSITION SENSOR (NEAR TOP OF ACCELERATOR PEDAL ASSEMBLY) BRN WIRE COMPUTER DATA LINES SYSTEM DK BLU WIRE DK BLU/ WHT WIRE DK BLU/VIO WIRE DK BLU/WHT WIRE DRIVER OUTSIDE REARVIEW MIRROR LEFT TURN SIGNAL REPEATER LAMP FUSE GMLAN LO SPD GRN WIRE GRY/BRN WIRE HOT AT ALL TIMES HOT W/ IGNITION MAIN RELAY ENERGIZED INSTRUMENT CLUSTER LEFT TURN IND LOGIC LT BLU WIRE LT GRN WIRE LT GRN/ VIO WIRE LT GRN/VIO WIRE PASSENGER OUTSIDE REARVIEW MIRROR PPL RED/ LT BLU WIRE RED/WHT WIRE RIGHT FRONT SIDE MARKER LAMP RIGHT PARK/ TURN SIGNAL LAMP RIGHT REAR TURN SIGNAL LAMP RIGHT TAIL LAMP RIGHT TAIL/ STOP LAMP RIGHT REAR SIDE MARKER LAMP RIGHT TURN IND RIGHT TURN SIGNAL REPEATER LAMP RUN/CRANK IGNITION 1 VOLT SER DATA TURN SIGNAL/ MULTI-FUNCTION SWITCH UNDERHOOD FUSE BLOCK (LEFT SIDE OF BATTERY) VIO WIRE VIO/GRY WIRE W/ HID W/ HID RIGHT HEADLAMP W/ POWER FOLDING OUTSIDE MIRROR W/O HID W/O POWER FOLDING OUTSIDE MIRROR WHT WIRE WHT/YEL WIRE

4 6 NETWORK BUS 3 AJAR SW SIG AJAR SW SIG ANT LO REF (2) ANT LO REF (5) ANT SIG (2) BLK WIRE BLK/BRN WIRE BLK/LT GRN WIRE BLK/YEL WIRE BLU WIRE BRN WIRE BRN/YEL WIRE COMPUTER DATA LINES SYSTEM LOGIC DK BLU WIRE DK BLU/VIO WIRE DOOR HANDLE TOUCH SENSOR DR LK CTRL SW LK SIG ANT SIG (5) DRIVER DOOR HANDLE KEYLESS ENTRY ANTENNA DRIVER DOOR LATCH ASSEMBLY DRIVER EXTERIOR DOOR HANDLE ASSEMBLY DRIVER EXTERIOR DOOR HANDLE SWITCH DRIVER EXTERIOR DOOR HANDLE TOUCH SENSOR DRIVER INFORMATION CENTER DISPLAY SECURITY IND DRIVER WINDOW MOTOR (DRIVER'S DOOR) DRIVER WINDOW SWITCH GMLAN SERIAL DATA GRN WIRE GRN/YEL WIRE GRY WIRE GRY/DK BLU WIRE GRY/YEL WIRE INSTRUMENT CLUSTER KEYLESS ENTRY CONTROL MODULE (RIGHT KICK PANEL) LEFT REAR EXTERIOR DOOR HANDLE SWITCH LT GRN WIRE LT GRN/WHT WIRE NETWORK BUS 3 ORG/ WIRE PACK) PASS DR SW LK CTRL ANT SIG (1) ANT LO REF (1) PASSENGER DOOR HANDLE KEYLESS ENTRY ANTENNA PASSENGER EXTERIOR PASSENGER EXTERIOR DOOR HANDLE ASSEMBLY PASSENGER EXTERIOR DOOR HANDLE SWITCH PASSENGER WINDOW MOTOR (FRONT PASSENGER'S DOOR) PPL PPL PASS DR UNLATCH SW SIG DRV DR UNLATCH SW SIG REAR FASCIA KEYLESS ENTRY ANTENNA (BEHIND REAR BUMPER) RED WIRE RIGHT REAR EXTERIOR DOOR HANDLE SWITCH STATUS CTRL UNLOCK SIGNAL VIO/DK BLU WIRE VIO/GRY WIRE WHT WIRE WHT/VIO WIRE YEL WIRE YEL/BLK WIRE YEL/DK BLU WIRE YEL/VIO WIRE