Powertrain Control Module (PCM) Connector End Views

Identifying PCM Connector C1 (Back View)

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		34-Pin WH
Pin	Wire Color	Function
1	YE	Fuel Injector 1 Control
2	BK	Fuel Injector 2 Control
3	WH	Fuel Injector 3 Control
4	BU	Fuel Injector 4 Control
5	BN	Ground
6	WH/BK	Ground
7	WH/BK	Ground
8	RD/BU	Ignition Trigger Signal Coil 1
9	YE/GN	Ignition Trigger Signal Coil 2
10	GY	Ignition Trigger Signal Coil 3
11	WH	Ignition Trigger Signal Coil 4
12	BK	Crank Signal
13	BK/YE	Camshaft Position (CMP) Actuator Solenoid Valve High Control
14	YE	Camshaft Position (CMP) Actuator Solenoid Valve Control Low
15	BU/WH	Auxiliary Intake Air Control Solenoid Control
16	BK/BU	Idle Air Control (IAC) Valve Control
17	-	Not Used
18	YE	5-Volt Reference Circuit
19	WH	Engine Coolant Temperature (ECT) Sensor Input
20	YE/BK	Intake Air Temperature (IAT) Sensor Input
21	L-GN	Throttle Position (TP) Sensor Input
22-23	-	Not Used
24	BU/YE	Ignition Fail Safe Input
25	RD	EVAP Canister Vent Solenoid Valve Control
26	BK	Camshaft Position (CMP) Sensor Input
27	BK	Crankshaft Position (CKP) Sensor Input
28	BN	Sensor Ground
29	BU/WH	Mass Air Flow (MAF) Sensor Signal Low
30	GN	Mass Air Flow (MAF) Sensor Signal High
31-33	-	Not Used
34	WH	CMP Sensor and CKP Sensor Ground

Identifying PCM Connector C2 (Back View)

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		35-Pin WH
Pin	Wire Color	Function
1	BK	Knock Sensor (KS) Signal High
2	WH	Knock Sensor (KS) Signal Low
3-5	-	Not Used
6	PK	Heated Oxygen Sensor (HO2S) 1 Heater Circuit Control
7	WH/BK	Ground
8	GY	EVAP Vacuum Leak Pump Control
9	L-GN/BK	Fan 2 Relay Control
10-15	-	Not Used
16	BU/YE	Rocker Arm Oil Control Solenoid Valve Control High
17	BK	Rocker Arm Oil Control Solenoid Valve Control Low
18	-	Not Used
19	BU/BK	EVAP Canister Purge Solenoid Valve Control
20	-	Not Used
21	L-GN	Fan 1 Relay Control
22	RD	Heated Oxygen Sensor (HO2S) 1 Input
23-26	-	Not Used
27	YE	AC Pressure Switch
28	WH/BK	Ground
29	-	Not Used
30	BU/RD	Power Steering Pressure (PSP) Switch Input
31-35	-	Not Used

Identifying PCM Connector C3 (Back View)

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		35-Pin WH
Pin	Wire Color	Function
1-2	-	Not Used
3	BK	Engine Speed Output
4	BK/WH	EFI Relay High Control
5	YE/BK	AC Compressor Clutch Relay Control
6-7	-	Not Used
8	BU/WH	Cruise Control Idle
9-13	-	Not Used
14	YE/RD	Engine Coolant Temperature Gage Output
15	BU/RD	Serial Data
16	GN/RD	Circuit Opening Relay Control
17	PU/WH	Vehicle Speed Sensor (VSS) Input
18	-	Not Used
19	GN/WH	Brake Switch Signal
20-22	-	Not Used
23	WH	Heated Oxygen Sensor (HO2S) 2 Input
24-30	-	Not Used
31	BK/WH	Rocker Arm Oil Pressure Switch Input
32	BK/BU	Evaporator Temperature Sensor Input
33	GN/WH	AC On Signal
34	GN	Secondary AIR Pressure Sensor Input
35	-	Not Used

Identifying PCM Connector C4 (Back View)

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		31-Pin WH
Pin	Wire Color	Function
1	BK	Ignition Positive Voltage
2	-	Not Used
3	RD/WH	Battery Voltage
4	BK/BU	Secondary AIR Solenoid Valve Control
5	BK/OG	Secondary AIR Pump Relay Control
6	-	Not Used
7	PK/BK	Heated Oxygen Sensor (HO2S) 2 Heater Circuit Control
8	-	Not Used
9	BK/OG	Ignition Positive Voltage
10	YE	AC Request Signal
11	RD/YE	MIL Control
12	GN	Electrical Load Idle-Up Signal, Tail Lamps
13	WH	Electrical Load Idle-Up Signal, Rear Defogger
14	YE	Supplemental Inflatable Restraint (SIR) System Signal
15-18	-	Not Used
19	PK	Data Link Connector (DLC)
20	PK/BK	Diagnostic Request Circuit
21	BU	Fuel Tank Pressure (FTP) Sensor Input
22-31	-	Not Used