2005 Chevrolet ClassicFACTORY OEM SERVICE PROCEDURE

Body Control Module (BCM) Connector End Views

Body Control Module (BCM) C1

GM73152Courtesy of GENERAL MOTORS CORP.
Connector Part Information
  • 12084945
  • 16-Way F Micro-Pack 100 Series (GRY)
Pin Wire Color Circuit No. Function
A1 PNK/WHT 1970 Headlamp Low Beam Relay Control
A2 DK GRN
/WHT		 1317 Fog Lamp Relay Control (T96)
A3 GRY/BLK 308 Park Lamp Switch On Signal
A4 BLK 28 Horn Relay Control
A5-A7 - - Not Used
A8 PPL 1600 Ignition 0 Voltage
B1 WHT 1080 Park Lamp Relay Control
B2 - - Not Used
B3 LT BLU 1344 Trunk Release Relay Control
B4 - - Not Used
B5 LT GRN
/BLK		 592 DRL Relay Control
B6 - - Not Used
B7 LT GRN
/BLK		 394 Driver Door Ajar Switch Signal
B8 BRN 341 Ignition 3 Voltage
Body Control Module (BCM) C2

GM73156Courtesy of GENERAL MOTORS CORP.
Connector Part Information
  • 12110088
  • 24-Way F Micro-Pack 100 Series (GRY)
Pin Wire Color Circuit No. Function
A1 - - Not Used
A2 WHT 682 Door Lock Lock/Unlock Signal
A3 YEL/BLK 1138 DRL Ambient Light Sensor Low Reference
A4 - - Not Used
A5 PNK 1200 Headlamp High Beam Signal
A6 BLK 1835 Security System Sensor Low Reference
A7 BLK/WHT 1576 Trunk Release Switch Signal
A8 PPL 16 Turn Signal Flasher Signal
A9 LT BLU 1134 Park Brake Switch Signal
A10-A11 - - Not Used
A12 PNK 849 Brake Fluid Level Sensor Signal
B1 ORN 1732 Courtesy Lamps Supply Voltage
B2 LT GRN
/BLK		 1137 DRL Ambient Light Sensor Signal
B3 - - Not Used
B4 DK BLU 1201 Headlamp Low Beam Signal
B5 - - Not Used
B6 YEL 1836 Security System Sensor Signal
B7 LT BLU
/BLK		 1322 SPI Serial Data B
B8 BRN 9 Park Lamp Supply Voltage
B9 PNK 439 Ignition 1 Voltage
B10 LT BLU 395 Passenger Door Ajar Switch Signal
B11 BLK/WHT 238 Driver Seat Belt Switch Signal
B12 LT GRN 80 Key In Ignition Switch Signal
Body Control Module (BCM) C3

GM130689Courtesy of GENERAL MOTORS CORP.
Connector Part Information
  • 12110244
  • 24-Way F Micro-Pack 100 Series (PNK)
Pin Wire Color Circuit No. Function
A1 - - Not Used
A2 YEL 356 Driver Door Lock Relay Unlock Control
A3 YEL 1321 SPI Serial Data A
A4 ORN 192 Front Fog Lamp Switch Signal (T96)
A5 - - Not Used
A6 BLK/WHT 99 Windshield Washer Fluid Level Signal
A7 PNK/BLK 1323 SPI Serial Data Clock
A8 LT BLU 195 Door Lock Control
A9 - - Not Used
A10 BLK/WHT 151 Ground
A11 WHT 156 Courtesy Lamp Low Control
A12 ORN 340 Battery Positive Voltage
B1 ORN 1540 Battery Positive Voltage
B2 PPL 1807 Class 2 Serial Data
B3 WHT 194 Door Unlock Control
B4 WHT 1459 Security System Sensor Supply Voltage
B5 - - Not Used
B6 YEL/BLK 68 Low Coolant Level Indicator Control
B7 LT GRN 66 A/C Request Signal
B8-B12 - - Not Used
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.