Buick LaCrosse I (2004-2009) low ref Wiring diagrams

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

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 43 8 SERIAL DATA FUEL LVEL SIG LOW REF PPL 3.6L 3.8L 3.8L PPL 31 57 OIL LVL SW SIG OIL PRESS SW 40 5 7 OIL PRESS SW 42 25 48 PPL FUEL LVEL SIG LOW REF SERIAL DATA AIR CONDITIONING SYSTEM ANTI-LOCK BRAKES SYSTEM BASE BCM CLASS 2 SERIAL DATA BLK WIRE BLK/WHT WIRE BODY CONTROL MODULE (BCM) (BELOW LEFT SIDE OF DASH, LEFT OF STEERING COLUMN) BRN WIRE COMPUTER DATA LINES SYSTEM DK GRN WIRE DOOR LOCK AJAR INDICATOR SWITCH DRIVER INFORMATION CENTER (DIC) TRACTION CONTROL (UPLEVEL) E/M (BASE) ENGINE CONTROL MODULE (ECM) (3.6L) (TOP OF ENGINE) ENGINE CONTROLS SYSTEM FUEL (UPLEVEL) GRY WIRE GRY/BLK WIRE HAZARD GAGES (UPLEVEL) INFO (UPLEVEL) LF DR AJAR SW SIG LOGIC ENGINE OIL PRESSURE (EOP) SENSOR (LEFT FRONT OF ENGINE BLOCK) LOW REF LR DR AJAR SW SIG LT BLU WIRE LT BLU/BLK WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE OIL PRESS SW ORG/ WIRE ORG/BLK WIRE PARK BRAKE SW SIG PARK BRAKE SWITCH (ON PARK BRAKE ASSEMBLY) PNK WIRE PPL PPL/WHT WIRE REAR COMPARTMENT LID LATCH (IN REAR COMPT LID) REAR LID AJAR SW RED WIRE RED/BLK WIRE RF DR AJAR SW SIG RR DR AJAR SW SIG TAN WIRE TAN/BLK WIRE TRIP SET/RESET ODO (UPLEVEL) WHT WIRE YEL WIRE

ABS INDICATOR ABS/TCS CLASS 2 SERIAL DATA AIR BAG INDICATOR BAT POS VOLTAGE BRAKE WARNING IND CTRL BCM CLASS 2 SERIAL DATA BCM CLASS 2 SERIAL DATA BLK WIRE BLK/WHT WIRE BRAKE FLUID LEVEL SWITCH (CENTER OF BRAKE FLUID RESERVOIR) BRAKE INDICATOR BRN/WHT WIRE CHANGE OIL INDICATOR CHARGING INDICATOR CHECK GAS CAP INDICATOR CLSTR FUSE COMPUTER DATA LINES SYSTEM CRUISE INDICATOR DOOR AJAR INDICATOR ENGINE CONTROLS SYSTEM ENGINE COOLANT TEMPERATURE GAGE ENGINE COOLANT TEMPERATURE INDICATOR FUEL GAGE GRY WIRE HDLP SUGGEST INDICATOR HIGH BEAM INDICATOR HOT AT ALL TIMES I/P FUSE BLOCK (BEHIND RIGHT SIDE OF DASH) IGN IGN PCM CLASS 2 SERIAL DATA IGN PCM/ECM CLASS 2 SERIAL DATA INSTRUMENT PANEL CLUSTER (IPC) IPC CLASS 2 SERIAL DATA PASS SEAT BELT IND IPC/BCM CLASS 2 SERIAL DATA KM/H INDICATOR LEFT TURN INDICATOR LOGIC LOW COOLANT INDICATOR LOW FUEL WARNING LAMP INDICATOR LOW REF LOW TIRE PRESSURE INDICATOR LOW WASHER FLUID INDICATOR MALFUNCTION INDICATOR LAMP (MIL) MPH INDICATOR ODO/TRIP OIL LEVEL INDICATOR LAMP ORG/ WIRE ORG/BLK WIRE P R N D 3 2 1 PARK BRAKE SWITCH (ON PARK BRAKE ASSEMBLY) PCM CLASS 2 SERIAL DATA PCM/ECM CLASS 2 SERIAL DATA PCM/ECM CLASS 2 SERIAL DATA IGN PPL REAR HATCH AJAR INDICATOR REDUCED ENGINE POWER INDICATOR RIGHT TURN INDICATOR SDM CLASS 2 SERIAL DATA SEAT BELT INDICATOR SECURITY INDICATOR SERVICE VEHICLE SOON INDICATOR SPEEDOMETER SUPPLEMENTAL RESTRAINTS SYSTEM TACHOMETER TAN/WHT WIRE TRACTION OFF INDICATOR TURN AUDIBLE INDICATOR WHT WIRE

A/C REFRIGERANT PRESSURE SENSOR (ON LEFT SIDE OF ENGINE COMPT, ON ACCUMULATOR) BLK WIRE BLK/WHT WIRE BRN WIRE CAMSHAFT POSITION ACTUATOR SOLENOID (EXHAUST BANK 1) CAMSHAFT POSITION ACTUATOR SOLENOID (EXHAUST BANK 2) CAMSHAFT POSITION ACTUATOR SOLENOID (INTAKE BANK 1) CAMSHAFT POSITION ACTUATOR SOLENOID (INTAKE BANK 2) CAMSHAFT POSITION SENSOR EXHAUST BANK 1 CAMSHAFT POSITION SENSOR EXHAUST BANK 2 CAMSHAFT POSITION SENSOR INTAKE BANK 1 CAMSHAFT POSITION SENSOR INTAKE BANK 2 DK GRN WIRE DK GRN/WHT WIRE EVAPORATIVE EMISSION (EVAP) CANISTER PURGE SOLENOID VALVE (TOP CENTER OF ENGINE) GRY WIRE LOW REF LT GRN WIRE MANIFOLD ABSOLUTE PRESSURE SENSOR (TOP REAR OF ENGINE, NEAR FUEL INJECTORS) MASS AIR FLOW/ INTAKE AIR TEMPERATURE SENSOR (IN AIR INTAKE TUBE) ORG/ WIRE ORG/BLK WIRE PNK PPL WIRE PNK WIRE PNK/BLK WIRE PPL PPL 18 19 RED/BLK WIRE SIGNAL TAN WIRE TAN/WHT WIRE THROTTLE ACTUATOR CONTROL MODULE (AT THROTTLE BODY) WHT/BLK WIRE YEL WIRE

ACCELERATOR PEDAL POSITION SENSOR (ABOVE ACCELERATOR PEDAL) AIR CONDITIONING SYSTEM ANTI-LOCK BRAKE SYSTEM AUTOMATIC TRANSMISSION BLK WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE CLASS 2 DATA CLU RLY CTRL MIL CTRL COMPUTER DATA LINES SYSTEM COOLING FANS SYSTEM CRUISE CONTROL SYSTEM DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENGINE CONTROL MODULE (TOP OF ENGINE) FUEL LEVEL SENSOR GMLAN BUS- GRY WIRE HOT AT ALL TIMES I/P FUSE BLOCK (BEHIND RIGHT SIDE OF DASH) IGN 3 VOLT CC SW SIG APP SENS SIG IGNITION SWITCH INSTRUMENT PANEL CLUSTER LAN BUS + LOCK LOGIC IGN LOW REF LT BLU WIRE MALFUNCTION INDICATOR LAMP NAVIGATION SYSTEM 6105 5069 2759 NCA WIRE ORG/ WIRE ORG/BLK WIRE P/N SIG EVAP SOL CTRL PNK IGN 1 VOLT FAN RLY CTRL ENG SPD SIG WIRE PNK IGN 1 VOLT WIRE PNK WIRE PPL PPL FUEL LEV SIG MAF SIG APP SENS 2 SIG PPL LOW REF A/C REF PRES STOP LP SW IAT SIG TANK PRES SIG PPL/WHT WIRE RED/BLK WIRE REQ TORQ SIG RLY COIL CTRL BATTERY + DELV TORQUE SIG RLY CTRL FAN RLY CTRL RUN WIRE STARTING/ CHARGING SYSTEM 625 540 464 TAN (OR BLK) WIRE TAN WIRE TAN/BLK WIRE TAN/WHT WIRE TRANSMISSION INTERNAL MODE SWITCH P/N UNDERHOOD FUSE BLOCK UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) VSS GMLAN BUS+ MAIN RLY CTRL LOW REF LOW REF WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

5 VOLT REF 1 5 VOLT REF 1 5 VOLT REF 1 BLK WIRE BLK/WHT WIRE BRN WIRE CMP SENSOR LOW ENG SPEED MED ENG SPEED LOW REF LOW REF OIL LEVEL SW DK BLU WIRE DK GRN/WHT WIRE ECT SENSOR SIG EGR SOL HIGH EGR SOL LOW ENGINE COOLANT TEMPERATURE SENSOR (ON TOP RIGHT OF INTAKE MANIFOLD) ENGINE OIL PRESSURE SWITCH (BELOW POWER STEERING PUMP) EVAP PURGE SOL EVAPORATIVE EMISSION (EVAP) CANISTER PURGE SOLENOID VALVE (TOP, REAR OF ENGINE) GEN FIELD KNOCK SENSOR 1 GEN ON SIG GENERATOR GROUND GRY WIRE HEATED OXYGEN IC TIMING CTRL KNOCK SENSOR (KS) 1 (FRONT LEFT SIDE OF ENGINE) KNOCK SENSOR (KS) 2 (RIGHT SIDE OF ENGINE, BELOW EXHAUST MANIFOLD) LOW REF LT BLU WIRE LT BLU/BLK WIRE LT GRN WIRE LT GRN/BLK WIRE MAP SENSOR SIG NCA WIRE OIL PRESS SIG KNOCK SENSOR 2 AIR SOL CTRL ORG/BLK WIRE PNK PNK WIRE PNK WIRE PNK/BLK WIRE PPL/WHT WIRE RED WIRE RED/BLK WIRE TAN WIRE TAN/BLK WIRE TAN/WHT WIRE WHT WIRE YEL WIRE YEL/BLK WIRE

5 VOLT REF AAP SENSOR 1 ACCELERATOR PEDAL POSITION SENSOR (ABOVE ACCELERATOR PEDAL) APP SENSOR 2 BLK WIRE BLK/WHT WIRE BODY CONTROL MODULE (BEHIND LEFT SIDE OF DASH, LEFT OF STEERING COLUMN) BREAKOUT, TOWARDS ICM) BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE ELEK IGN FUSE 24 ETC FUSE 17 FROM P/TRAIN RELAY (DIAGRAM 4 OF 5) FUEL INJ FUSE 20 GROUND GRY WIRE HOT IN RUN OR START IGN 1 VOLT IGNITION CONTROL MODULE (ICM) (TOP LEFT FRONT OF ENGINE) LOW REF LT BLU WIRE LT BLU/BLK WIRE LT BLU/WHT WIRE ORG/BLK WIRE PNK PNK WIRE PNK WIRE PNK/BLK WIRE PPL PPL/WHT WIRE PRIMARY UART RED/BLK WIRE SEC UART SECONDARY AIR INJECTION SOLENOID RELAY (PZEV) (NEAR AIR CLEANER DUCT) SPARK PLUGS STOP LAMP STOP LAMP SWITCH SIGNAL TAN WIRE TAN/BLK WIRE TAN/WHT WIRE THROTTLE ACTUATOR CONTROL MODULE (AT THROTTLE BODY) TRANS SOL FUSE 21 UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) VEHICLE SPD WHT WIRE WHT/BLK WIRE YEL WIRE

1-2 SHIFT SOLENOID 2-3 SHIFT SOLENOID A/T FLUID TEMP SENSOR AIR PRES SENS AT ISS SIG AUTOMATIC TRANSMISSION PRESSURE CONTROL SOLENOID BLK WIRE BLK/WHT WIRE BOOST SOL BRN WIRE DK BLU/WHT WIRE DK GRN WIRE GRY WIRE IAT SENSOR SIG INPUT SHAFT SPEED SENSOR LOW REF LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE MAF SENSOR SIG NEAR AIR CLEANER ASSEMBLY) ORG/ WIRE PC SOL PNK PNK WIRE PNK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF ENGINE COMPARTMENT) PPL RED WIRE RED/BLK WIRE SHIFT SOL TAN WIRE TAN/BLK WIRE TAN/WHT WIRE TCC RELEASE SWITCH TCC SOL TCC SW SIG TFT SENSOR SIG TORQUE CONVERTER CLUTCH SOLENOID TR SW A TR SW B TR SW C TR SW P TRANSMISSION INTERNAL MODE SWITCH VEHICLE SPEED SENSOR (RIGHT SIDE OF TRANSMISSION, NEAR RIGHT AXLE SHAFT) VSS SIG WHT WIRE YEL WIRE YEL/BLK WIRE

12 2 1 B+ CLASS 2 GND IGN 5-VOLT REF 1 5-VOLT REF 2 A/C PRESS SIG STOP LAMP SW A/C CLUTCH RELAY RELAY CTRL AIR CONDITIONING SYSTEM BLK WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE CLASS 2 DATA CLSTR FUSE COOLING FANS SYSTEM CRUISE CONTROL SYSTEM DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENGINE COMPARTMENT, NEAR AIR CLEANER ASSEMBLY) EVAP VENT SOL FUEL PUMP RELAY FUEL PUMP, SENDER ASSEMBLY FUEL TANK DK FUEL TANK PRESS FUEL TANK PRESSURE SENSOR GRN WIRE GRY WIRE HIGH FAN HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK (BEHIND RIGHT SIDE OF DASH) IGNITION SWITCH INSTRUMENT PANEL CLUSTER LOCK LOGIC LOW FAN LOW REF MALFUNCTION INDICATOR LAMP (MIL) MIL CONTROL LOW REF LOW REF NAVIGATION SYSTEM NCA WIRE ORG/ WIRE PCM FUSE 15 PNK WIRE POWERTRAIN CONTROL MODULE (LEFT SIDE OF PPL PPL FUEL LEVEL SIG CRUISE SIG RED/BLK WIRE RUN WIRE STARTING/CHARGING SYSTEM UNDERHOOD FUSE BLOCK (MOUNTED TO RIGHT STRUT TOWER) WHT WIRE YEL/BLK WIRE