Buick LaCrosse I (2004-2009) underhood fuse block (mounted to right strut tower) Wiring diagrams

A/C CLU DIODE A/C CLUTCH FUSE 13 A/C COMP RELAY 38 A/C COMPRESSOR CLUTCH SOLENOID A/C COMPRESSOR TEMPERATURE SWITCH A/C REQUEST IND A/C REQUEST SWITCH AIR TEMP A AIR TEMP B AIR TEMP A AIR TEMP B AUTO OFF BLOWER MOTOR SW BATTERY IGN 1 VOLT CLASS 2 SERIAL BLK WIRE BLK/WHT WIRE BRN WIRE COMPUTER DATA LINES SYSTEM 8 1450 734 720 INTERIOR LIGHTS SYSTEM DEFOGGER IND DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE FAN 1 FUSE 29 FAN 1 RELAY 42 FAN 2 FUSE 32 FAN 2 RELAY 46 FAN 3 RELAY 43 GROUND GRY WIRE GRY/BLK WIRE HIGH LOW HOT AT ALL TIMES HOT IN RUN OR START HVAC CONTROL MODULE (CENTER OF DASH) ILLUM LOGIC LOWER LEFT AIR TEMPERATURE SENSOR (BEHIND HVAC CONTROL MODULE) LOWER RIGHT AIR TEMPERATURE SENSOR (BEHIND HVAC CONTROL MODULE) LT BLU WIRE LT BLU/BLK WIRE LT GRN WIRE LT GRN/BLK WIRE MODE ACTUATOR (LOWER LEFT SIDE OF HVAC ASSEMBLY) MODE DOOR A MODE DOOR B MODE SWITCH NCA WIRE ORG/ WIRE ORG/BLK WIRE PNK WIRE PNK/WHT WIRE PPL REAR DEFOGGER SWITCH RECIRATION A RECIRATION B RECIRCULATION ACTUATOR (NEAR RIGHT "A" PILLAR, ON UPPER HVAC CASE) RECIRCULATION IND RECIRCULATION SWITCH SENSOR SIG SENSOR SIG LOW REF SENSOR SIG LOW REF SENSOR SIG LOW REF SENSOR SIG LOW REF SENSOR SIG SENSOR SIG LOW REF PPL SPEED CTRL TAN WIRE TAN/BLK WIRE TAN/WHT WIRE TEMPERATURE CONTROL SW UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) WHT WIRE WHT/BLK WIRE YEL WIRE

9 39 25 48 49 A/C PRESS SIGNAL A/C CLU DIODE A/C CLUTCH FUSE 13 A/C COMP RELAY 38 A/C COMPRESSOR CLUTCH SOLENOID A/C COMPRESSOR TEMPERATURE SWITCH A/C REFRIGERANT PRESSURE SENSOR (ON LEFT SIDE OF ENGINE COMPT, ON ACCUMULATOR) A/C REQUEST IND A/C REQUEST SWITCH BATTERY IGN 1 VOLT CLASS 2 SERIAL BLK WIRE BLK/WHT WIRE COMPUTER DATA LINES SYSTEM DISPLAY FUSE 18 DK GRN WIRE DK GRN/WHT WIRE ENGINE CONTROL MODULE (ECM) (TOP OF ENGINE) ENGINE CONTROLS SYSTEM GROUND GRY WIRE HOT AT ALL TIMES HOT IN RUN OR START HVAC CONTROL MODULE (CENTER OF DASH) HVAC FUSE I/P FUSE BLOCK (BEHIND RIGHT SIDE OF DASH) LOGIC LOW REF CLASS 2 SERIAL A/C COMP CLUTCH NCA WIRE ORG/ WIRE PNK WIRE RED/BLK WIRE UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) WHT WIRE

23 7 ECT SENS SIG LOW REF 4 20 48 HI SPD FAN RLY LO SPD FAN RLY CLASS 2 SERIAL BLK WIRE COMPUTER DATA LINES SYSTEM DK BLU WIRE DK GRN WIRE ENGINE CONTROL MODULE (ECM) (TOP OF ENGINE) FAN 1 FUSE 29 FAN 1 RELAY 42 FAN 2 FUSE 32 FAN 2 RELAY 46 FAN 3 RELAY 43 GRY WIRE HOT AT ALL TIMES LEFT COOLING FAN MOTOR (ON LEFT SIDE OF RADIATOR) LT BLU WIRE RIGHT COOLING FAN MOTOR (ON RIGHT SIDE OF RADIATOR) TAN WIRE UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) WHT WIRE YEL WIRE

10 59 STOP SWITCH SIG SET/COAST RESUME/ ACCELERATE SIGNAL 10 VOLT REF 5 VOLT REFERENCE 1 PPL LOW REFERENCE 5 VOLT REFERENCE 2 LOW REFERENCE APP SENSOR 2 SIGNAL 55 54 15 8 31 39 TP SENS 1 SIG ACCELERATOR PEDAL POSITION (APP) SENSOR (ABOVE ACCELERATOR PEDAL) BAT POS VOL BCM CLASS 2 DATA BLK WIRE BLU WIRE BODY CONTROL MODULE (BCM) (BEHIND LEFT SIDE OF DASH, LEFT OF STEERING COLUMN) BRN WIRE CLSTR FUSE COMPUTER DATA LINES SYSTEM CRUISE CAN SW SIG CRUISE FUSE CRUISE INDICATOR CRUISE SET XX MPH CRUISE SWITCH DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE ENGINE CONTROL MODULE (ECM) (TOP OF ENGINE) GROUND DISTRIBUTION SYSTEM GRY WIRE HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK (BEHIND RIGHT SIDE OF DASH) IGN INFLATABLE RESTRAINT STEERING WHEEL MODULE COIL (IN STEERING COLUMN) INSTRUMENT PANEL CLUSTER (IPC) IPC CLASS 2 SER DATA LEFT STEERING WHEEL CONTROLS LOGIC LOW REF LT BLU WIRE LT GRN WIRE MESSAGE MESSAGE CENTER (UP LEVEL) NCA WIRE ON IND. ORG/ WIRE PCM CLASS 2 SER DATA PNK WIRE PPL REAR OBJECT SENSOR CONTROL MODULE RES+ SET- STOP LAMP SIG STOP SWITCH SIG TAC MTR CTRL 2 TP SENS 2 SIG TAC MTR CTRL 1 LOW REF PPL TAN WIRE THROTTLE ACTUATOR CONTROL (TAC) MODULE (AT THROTTLE BODY) TRANSMISSION CONTROL MODULE (TCM) UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) VEH SPD SIG VEHICLE SPEED SENSOR (VSS) VSS HIGH SIG VSS LOW SIG WHT WIRE WHT/BLK WIRE YEL WIRE

12 13 14 15 16 PPL 8 1450 734 720 INTERIOR LIGHTS SYSTEM A/C CLU DIODE A/C CLUTCH FUSE 13 A/C COMP RELAY 38 AUTO OFF BLOWER MOTOR SW BATTERY IGN 1 VOLT CLASS 2 SERIAL BLK WIRE BLK/WHT WIRE BRN WIRE COMPUTER DATA LINES SYSTEM DEFOGGER IND DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE DK GRN/WHT WIRE FAN 1 FUSE 29 FAN 1 RELAY 42 FAN 2 FUSE 32 FAN 2 RELAY 46 FAN 3 RELAY 43 GROUND GRY WIRE GRY/BLK WIRE HIGH LOW HOT AT ALL TIMES HOT IN RUN OR START HVAC CONTROL MODULE (CENTER OF DASH) ILLUM LOGIC LOWER LEFT AIR TEMPERATURE SENSOR (BEHIND HVAC CONTROL MODULE) LOWER RIGHT AIR TEMPERATURE SENSOR (BEHIND HVAC CONTROL MODULE) LT BLU WIRE LT BLU/BLK WIRE LT GRN WIRE LT GRN/BLK WIRE MODE ACTUATOR (LOWER LEFT SIDE OF HVAC ASSEMBLY) MODE SWITCH ORG/ WIRE ORG/BLK WIRE PNK WIRE PNK/WHT WIRE REAR DEFOGGER SWITCH RECIRCULATION ACTUATOR (NEAR RIGHT "A" PILLAR, ON UPPER HVAC CASE) RECIRCULATION IND RECIRCULATION SWITCH REQUEST SWITCH A/C A/C REQUEST IND SENSOR SIG SENSOR SIG LOW REF SENSOR SIG LOW REF SENSOR SIG LOW REF SENSOR SIG LOW REF SENSOR SIG SENSOR SIG LOW REF PPL SPEED CTRL TAN WIRE TAN/BLK WIRE TAN/WHT WIRE TEMPERATURE CONTROL SW UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) WHT WIRE WHT/BLK WIRE YEL WIRE

31 4 7 15 33 A/C PRESS SIGNAL A/C CLU DIODE A/C CLUTCH FUSE 13 A/C COMP RELAY A/C REFRIGERANT PRESSURE SENSOR (ON LEFT SIDE OF ENGINE COMPT, ON ACCUMULATOR) A/C REQUEST IND A/C REQUEST SWITCH AUTOMATIC A/C BATTERY IGNITION 1 BLK WIRE BLK/WHT WIRE CLASS 2 SERIAL COMPUTER DATA LINES SYSTEM DISPLAY FUSE 18 DK GRN WIRE DK GRN/WHT WIRE GROUND GRY WIRE HARNESS, APPROXI- MATELY 20 CM FROM HOT AT ALL TIMES HOT AT ALL TIMES I/P FUSE BLOCK HVAC FUSE (BEHIND RIGHT SIDE OF DASH) HOT IN RUN OR START HVAC CONTROL MODULE (CENTER OF DASH) LOGIC LOW REF CLASS 2 SERIAL A/C COMP CLUTCH MANUAL A/C ORG/ WIRE PNK WIRE POWERTRAIN CONTROL MODULE (PCM) RED/BLK WIRE TOWARDS BRAKE PEDAL POSITION SENSOR) UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) WHT WIRE

50 48 15 HI SPD FAN RLY LO SPD FAN RLY CLASS 2 SERIAL 55 29 ECT SENS SIG LOW REF BLK WIRE COMPUTER DATA LINES SYSTEM DK BLU WIRE DK GRN WIRE ENGINE COOLANT TEMPERATURE (ECT) SENSOR (ON TOP RIGHT OF INTAKE MANIFOLD) FAN 1 FUSE 29 FAN 1 RELAY 42 FAN 2 FUSE 32 FAN 2 RELAY 46 FAN 3 RELAY 43 GRY WIRE HOT AT ALL TIMES LEFT COOLING FAN MOTOR (ON LEFT SIDE OF RADIATOR) LT BLU WIRE RIGHT COOLING FAN MOTOR (ON RIGHT SIDE OF RADIATOR) UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) WHT WIRE YEL WIRE

10 VOLT REF 32 22 44 STOP SWITCH SIG VEHICLE SPEED SIGNAL 5 VOLT REF ACCELERATOR PEDAL POSITION (APP) SENSOR (ABOVE ACCELERATOR PEDAL) APP SENS 1 SIG APP SENS 2 SIG BAT POS VOL BLK WIRE BLU WIRE BODY CONTROL MODULE (BCM) (BEHIND LEFT SIDE OF DASH, LEFT OF STEERING COLUMN) BRN WIRE CLSTR FUSE COMPUTER DATA LINES SYSTEM CRUISE CAN SW SIG CRUISE FUSE CRUISE INDICATOR CRUISE SET XX MPH DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE GROUND DISTRIBUTION SYSTEM GRY WIRE HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK (BEHIND RIGHT SIDE OF DASH) IGN INFLATABLE RESTRAINT STEERING WHEEL MODULE COIL (IN STEERING COLUMN) INSTRUMENT PANEL CLUSTER (IPC) IPC CLASS 2 SER DATA LEFT STEERING WHEEL CONTROLS LOGIC LOW REF LT BLU WIRE LT GRN WIRE MESSAGE MESSAGE CENTER (UP LEVEL) NCA WIRE ON IND. ORG/ WIRE ORG/BLK WIRE PCM CLASS 2 SER DATA PNK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF ENGINE COMPT, NEAR AIR CLEANER ASSEMBLY) PPL PPL LOW REF REAR OBJECT SENSOR CONTROL MODULE RES+ SER DATA PRIMARY SER DATA SECONDARY SET CRUISE SWITCH SET/COAST RESUME/ ACCELERATE SIGNAL STOP LAMP SIG STOP LAMP SW SIG STOP SWITCH SIG BCM CLASS 2 DATA LOW REF TAN WIRE THROTTLE ACTUATOR CONTROL (TAC) MODULE (AT THROTTLE BODY) UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) VEH SPD SIG VEHICLE SPEED SENSOR (VSS) VEHICLE SPEED SIGNAL VSS HIGH SIGNAL VSS LOW SIGNAL WHT WIRE WHT/BLK WIRE YEL WIRE

15 21 PCM CLASS 2 SER DATA ENG SPEED SIG 3.6L 3.6L W/ ACTIVE BRAKE CONTROL 3.8L 48 15 5 37 ECM CLASS 2 SER DATA REQ TORQUE SIG ENG SPEED SIG DEL TORQUE SIG ABS FUSE 23 ABS MTR FUSE 31 ABS SOL FUSE 19 B+ MOTOR CONTROL B+ SOL VALVE CONTROL BLK WIRE BLK/WHT WIRE BRAKE PRESSURE MODULATOR VALVE (BPMV) BRN WIRE BRN/WHT WIRE COMPUTER DATA LINES SYSTEM DK BLU WIRE DK GRN WIRE ENG SPEED SIG (3.8L) HI SPD GMLAN SER DATA - (3.6L) ENGINE CONTROL MODULE (3.6L) (TOP OF ENGINE) ENGINE CONTROLS SYSTEM GRY WIRE GRY/BLK WIRE HOT AT ALL TIMES HOT W/ IGN 1 RELAY ENERGIZED HSV 2 (W/ TCS) LEFT FRONT INLET LEFT FRONT OUTLET LEFT REAR OUTLET LT BLU WIRE MAGNASTEER ACTUATOR (ON STEERING RACK ASSEMBLY) ORG/ WIRE ORG/BLK WIRE PNK PNK WIRE PNK WIRE PUMP MOTOR RED WIRE RIGHT FRONT INLET RIGHT LEFT FRONT REAR INLET OUTLET RIGHT REAR INLET RIGHT USV 1 (W/ TCS) REAR (W/ TCS) OUTLET SOLENOID VALVES TAN WIRE TAN/BLK WIRE TAN/WHT WIRE UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) USV 2 (W/ TCS) W/ ACTIVE BRAKE CONTROL W/ TRACTION CONTROL W/O ACTIVE BRAKE CONTROL WHT WIRE YEL WIRE

AUTOMATIC A/C MANUAL A/C BATT MAIN 3 FUSE 28 BCM CLASS 2 SERIAL DATA BLK WIRE BODY CONTROL MODULE (BCM) (BEHIND LEFT SIDE OF DASH, LEFT OF STEERING COLUMN) BRN WIRE COMPASS SENS RTN DEFOGGER DRIVER OUTSIDE REARVIEW MIRROR ELECTRONIC COMPASS MODULE (TOP RIGHT SIDE OF REAR PACKAGE SHELF) HOT AT ALL TIMES HTD MIR FUSE HVAC CLASS 2 SERIAL DATA INSTRUMENT PANEL CLUSTER (IPC) INSTRUMENT PANEL FUSE BLOCK (BEHIND RIGHT SIDE OF DASH) LOGIC LOGIC HVAC CONTROL MODULE (CENTER OF DASH) LT GRN WIRE ON IND. ORG/ WIRE PASSENGER OUTSIDE REARVIEW MIRROR REAR DEFOG RELAY CTRL REAR DEFOGGER SWITCH REAR WINDOW DEFOGGER GRID RED WIRE RR DEFOG RELAY UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) W/ DRIVER INFO CENTER DISPLAY WHT WIRE