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PCM Harness Resistance

Turn ignition switch to LOCK position. Disconnect PCM and appropriate component harness connectors. Check for open or short circuits between appropriate PCM harness connector terminal and appropriate component harness connector terminal. See POWERTRAIN CONTROL MODULE (PCM)  table. See WIRING DIAGRAMS. If harness is open or shorted, repair as necessary.

Fig 1: Identifying Powertrain Control Module (PCM) Harness Connector Terminals
G98H00866Courtesy of GENERAL MOTORS CORP.
POWERTRAIN CONTROL MODULE (PCM) (1)

Connector Terminal Wire Color Function
C1 1 & 2 ***** Not Used
C1 3 BRN/WHT CMP 1x Signal
C1 4-6 ***** Not Used
C1 7 TAN HO2S Bank 2 Sensor 1 Low
C1 8 PNK/BLK CMP Sensor Ground
C1 9 PPL Fuel Level Output
C1 10 TAN/BLK TCC Solenoid Control
C1 11 & 12 ***** Not Used
C1 13 WHT 3-2 Shift Solenoid Control
C1 14 ***** Not Used
C1 15 YEL/BLK VSS Output Signal (EBCM)
C1 16-18 ***** Not Used
C1 19 PPL/WHT HO2S Bank 1 Sensor 1 Signal
C1 20 ***** Not Used
C1 21 PPL HO2S Bank 2 Sensor 1 Signal
C1 22 PPL/WHT HO2S Bank 1 Sensor 3 Signal
C1 23 & 24 *****- Not Used
C1 25 TAN/WHT HO2S Bank 1 Sensor 1 Low
C1 26 TAN/WHT HO2S Bank 1 Sensor 3 Low
C1 27 ***** Not Used
C1 28 PPL CKP Sensor Ground
C1 29 LT GRN/BLK VSS Low
C1 30 PPL/WHT VSS High
C1 31 YEL CKP 3X Sensor Signal
C1 32 ***** Not Used
C2 1 ***** Not Used
C2 2 WHT EVAP Canister Vent Solenoid Control
C2 3 ***** Not Used
C2 4 YEL/BLK 2-3 Shift Solenoid Control
C2 5 ***** Not Used
C2 6 LT GRN 1-2 Shift Solenoid Control
C2 7 BRN TCC PWM Solenoid Control
C2 8 BLK Fuel Injector No. 1 Control
C2 9 YEL/BLK Fuel Injector No. 6 Control
C2 10 BRN EGR Pintle Position Signal
C2 11 & 12 ***** Not Used
C2 13 LT GRN/WHT IAC Coil B High
C2 14 LT BLU/WHT IAC Coil A High
C2 15 LT GRN/BLK Fuel Injector No. 2 Control
C2 16 PNK/BLK Fuel Injector No. 3 Control
C2 17 & 18 ***** Not Used
C2 19 DK BLU KS Signal
C2 20 WHT Tachometer Output
C2 21 LT GRN MAP Sensor Signal
C2 22 TAN IAT Sensor Signal
C2 23 YEL ECT Sensor Signal
C2 24 DK BLU TP Sensor Signal
C2 25 DK GRN Fuel Tank Pressure Sensor Signal
C2 26 ***** Not Used
C2 27 YEL/BLK TFT Sensor Signal
C2 28 YEL MAF Sensor Signal
C2 29 LT GRN/BLK IAC Coil B Low
C2 30 LT BLU/BLK IAC Coil A Low
C2 31 BLK/WHT Fuel Injector No. 5 Control
C2 32 LT BLU/BLK Fuel Injector No. 4 Control
C3 1 DK GRN/WHT A/C Compressor Enable Relay Control
C3 2 DK GRN/WHT EVAP Canister Purge Solenoid Control
C3 3 ***** Not Used
C3 4 BLK ECT/TP Sensor Ground
C3 5 RED Generator Control/ Monitoring
C3 6 RED/BLK Pressure Control Solenoid High
C3 7 & 8 ***** Not Used
C3 9 WHT IC Control
C3 10 ***** Not Used
C3 11 RED Transmission Range C Signal
C3 12 GRY TP Sensor Reference Voltage
C3 13 PPL Fuel Level Sensor Signal
C3 14 & 15 ***** Not Used
C3 16 LT BLU/WHT Pressure Control Solenoid Low
C3 17 BLK/WHT VCM Ground
C3 18 BLK/WHT VCM Ground
C3 19 BLK Sensor Ground (IAT/MAP/EGR/Fuel Tank Pressure)
C3 20 ***** Not Used
C3 21 ORG Battery Voltage
C3 22 DK BLU Transmission Range B Signal
C3 23 PNK Transmission Range A Signal
C3 24 ***** Not Used
C3 25 GRN/WHT A/C Request Signal
C3 26 WHT PRNDL P Signal
C3 27 GRY Reference Voltage
C3 28 GRY PRNDL C Signal
C3 29 ***** Not Used
C3 30 GRN A/C Pressure Signal
C3 31 BLK/WHT PRNDL A Signal
C3 32 YEL PRNDL B Signal
C4 1 DK GRN/WHT Fuel Pump Relay Control
C4 2 ***** Not Used
C4 3 DK GRN/WHT VSS Output Signal (TCCM, Cruise & TBC Modules)
C4 4 BRN/WHT VSS Output Signal (Speedometer)
C4 5 BRN/WHT MIL Control
C4 6-9 ***** Not Used
C4 10 PPL Brake Signal
C4 11 PPL Serial Data (Class I)
C4 12 ***** Not Used
C4 13 BRN Ignition Voltage
C4 14 YEL Serial Data (Class II)
C4 15 ***** Not Used
C4 16 RED EGR Valve Control
C4 17 PNK Ignition Voltage
C4 18 PNK Ignition Voltage
C4 19 BLK/WHT 4WD Front Wheel Lock Input
C4 20 WHT EGR Valve Low
C4 21 ***** Not Used
C4 22 BRN/WHT CPP Switch Signal
C4 23 GRY/BLK 4WD Low Signal
C4 24 LT BLU/BLK Cruise Engaged Signal
(1) See Fig 1 .