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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 PCM harness connector terminal and component harness connector terminal. See POWERTRAIN CONTROL MODULE (PCM) CONNECTOR I.D.  table. See WIRING DIAGRAMS article. If harness is open or shorted, repair as necessary.

Fig 1: Identifying Powertrain Control Module (PCM) Harness Connector Terminals
G98F00864Courtesy of GENERAL MOTORS CORP.
POWERTRAIN CONTROL MODULE (PCM) CONNECTOR I.D. (1)

Terminal Wire Color Function
1 BRN/WHT HO2S Heater Control (Rear)
2 BRN/BLU IAC Valve Control (Close)
3 BRN/YEL Fuel Injector 1 Control
4 BRN/BLU Fuel Injector 3 Control
5 BRN/BLK Fuel Injector 5 Control
6 BLK ECM Ground
7 BRN/GRN Intake Resonance Switchover Solenoid Valve Control
8 BRN/BLU Malfunction Indicator Lamp MIL) Control
9-11 ***** Not Used
12 BLK/BLU A/C Load Signal
13-14 ***** Not Used
15 BLK/WHT A/C Request Signal
16 BLU/RED IAT Sensor Signal
17 BLU/GRN MAF Sensor Signal
18 BRN/BLU HO2S Signal B2S1
19 BRN/BLU HO2S Signal B1S1
20 GRY/RED CKP Sensor Ground
21 BRN/GRN Transmission Torque Reduction Request Circuit
22-25 ***** Not Used
26 RED/BRN Battery Voltage
27 BRN/GRY Engine Controls Power Relay Control
28 BLK ECM Ground
29 BRN/RED IAC Valve Control (Open)
30 BRN/WHT HO2S Heater Control (Front)
31 BRN/GRN Fuel Injector 2 Control
32 BRN/RED Fuel Injector 4 Control
33 BRN/PPL Fuel Injector 6 Control
34 BLK ECM Ground
35 BRN/GRN Intake Plenum Switchover Solenoid
36 BRN/PPL A/C Relay Control
37 WHT AIR Pump Relay Control
38 GRY/RED/BLK CMP Sensor Signal
39 RED/BLK MIL Request
40 BRN/WHT Knock Sensor (KS) B2
41-43 ***** Not Used
44 BRN/BLU Throttle Position (TP) Sensor Signal
45 BRN/LT GRN Mass Air Flow (MAF) Sensor Signal Return
46 BRN/GRN H02S Ground
47 ***** Not Used
48 GRY Traction Control Torque Reduction Request
49 GRY/BLK Ignition Control (IC) 1-4
50 BLK/YEL Ignition Control (IC) 2-5
51 BLK/RED Ignition Control (IC) 3-6
52 ***** Not Used
53 BLU/BLK 5 Volt Reference
54 RED/BLU Switched Battery Voltage
55 BLK ECM Ground
56 BRN ECM Ignition Feed
57-60 ***** Not Used
61 BRN/RED EVAP Canister Purge Valve Control
62 PPL AIR Cut-Off Solenoid Valve Control
63 BRN Fuel Pump Relay Control
64 ***** Not Used
65 BRN/BLK EVAP Canister Vent Valve Control
66-67 ***** Not Used
68 ***** Traction Control Input/PWM Interface
69 BLK/RED P/N Signal
70 BRN/WHT Knock Sensor (KS) B1
71 BLU/GRN 5 V Reference Ground
72 BRN/YEL EVAP Fuel Tank Pressure Sensor Signal
73 BLU/BLK EVAP Fuel Tank Level Sensor Signal
74 BRN/BLU Engine Coolant Temperature ECT) Sensor Signal
75 ***** Not Used
76 BRN/BLU H02S Signal B2 S2
77 BRN/BLU H02S Signal B1 S2
78 GRN/WHT CKP Sensor Signal
79 BLU/RED Vehicle Speed/Theft Deterrent Signal
80 GRN Engine Speed Output
81 ***** Not Used
82 BRN/YEL ECM Data Output
83 GRY Engine Torque Output
84-87 ***** Not Used
88 BRN/WHT Serial Data
(1) Connector Terminal Identification not available at time of publication.