GM Service Manual Online
For 1990-2009 cars only
Table 1: Back View Of the PCM Connector C1 (Manual and 3-Speed A/T Only)
Table 2: Back View Of the PCM Connector C2 (Manual and 3-Speed A/T Only)
Table 3: Back View Of the PCM Connector C3 (Manual and 3-Speed A/T Only)
Table 4: Back View Of the PCM Connector C1 (4-Speed AT only)
Table 5: Back View Of the PCM Connector C2 (4-Speed AT only)
Table 6: Back View Of the PCM Connector C3 (4-Speed AT only)
Table 7: Back View Of the PCM Connector C4 (4-Speed AT only)

Back View Of the PCM Connector C1 (Manual and 3-Speed A/T Only)


Object Number: 60602  Size: CF

Connector Part Information

3-Speed AT and Manual Transmission only

26 Pin GRY Connector C1

Pin

Wire Color

Function

C1-1

RED

Camshaft Position (CMP) Actuator Solenoid Valve Control Low

C1-2

BLK

Camshaft Position (CMP) Actuator Solenoid Valve Control High

C1-3

BLU/YEL

Ignition Fail Safe Input

C1-4

RED

EVAP Pressure Switching Solenoid Control

C1-5

BLU/BLK

EVAP Canister Vent Solenoid Valve Control

C1-6

--

Not Used

C1-7

BLU/BLK

EVAP Canister Purge Solenoid Valve Control

C1-8

BLU/RED

Power Steering Pressure (PSP) Switch

C1-9

LT GRN

AC Condenser Fan Control

C1-10

--

Not Used

C1-11

BLK/RED

Fuel Injector 2 Control

C1-12

YEL

Fuel Injector 1 Control

C1-13

BRN

Ground

C1-14

BRN

Ground

C1-15

BLK/BLU

Idle Air Control (IAC) Valve Control Circuit

C1-16

YEL/BLU

Fuel Pump Cut-Off Signal (SIR SDM)

C1-17

BLU

Fuel Tank Pressure Sensor Input

C1-18

BLK

Knock Sensor (KS) Input

C1-19

--

Not Used

C1-20

RED/BLU

Ignition Trigger Signal Coil 1

C1-21

YEL/GRN

Ignition Trigger Signal Coil 2

C1-22

GRY

Ignition Trigger Signal Coil 3

C1-23

WHT

Ignition Trigger Signal Coil 4

C1-24

BLK

Fuel Injector 4 Control

C1-25

WHT

Fuel Injector 3 Control

C1-26

BRN

Ground

Back View Of the PCM Connector C2 (Manual and 3-Speed A/T Only)


Object Number: 60590  Size: CF

Connector Part Information

3-Speed AT and Manual Transmission only

16 Pin GRY Connector C2

Pin

Wire Color

Function

C2-1

YEL

Reference Voltage

C2-2

GRN

Mass Air Flow (MAF) Sensor Signal High

C2-3

YEL/BLK

Intake air Temperature (IAT) Sensor Input

C2-4

WHT

Engine Coolant Temperature (ECT) Sensor Input

C2-5

BLK

Crankshaft Position (CKP) Sensor Input

C2-6

WHT

Heated Oxygen Sensor (HO2S) 1 Input

C2-7

PNK

Heated Oxygen Sensor (HO2S) 1 Heater Circuit Control

C2-8

BRN

Ground

C2-9

BRN

Sensor Ground

C2-10

BLU/WHT

Mass Air Flow (MAF) Sensor Signal Low

C2-11

LT GRN

Throttle Position (TP) Sensor Input

C2-12

BLK

Camshaft Position Sensor (CMP) Sensor Input

C2-13

WHT

CMP Sensor and CKP Sensor Ground

C2-14

RED

Heated Oxygen Sensor (HO2S) 2 Input

C2-15

PNK

Heated Oxygen Sensor (HO2S) 2 Heater Circuit Control

C2-16

--

Not Used

Back View Of the PCM Connector C3 (Manual and 3-Speed A/T Only)


Object Number: 60597  Size: CF

Connector Part Information

3-Speed AT and Manual Transmission only

22 Pin GRY Connector C3

Pin

Wire Color

Function

C3-1

RED/WHT

Battery Voltage

C3-2

BLK

Electrical Load Idle-up Signal from Defogger

C3-3

GRN

Electrical Load Idle-up Signal from Taillights

C3-4

--

Not Used

C3-5

RED/YEL

Malfunction Indicator Light (MIL) Control

C3-6

BLU/WHT

Data Link Connector (Underhood) Diagnostic Request

C3-7

BLU/WHT

Cruise Control Idle

C3-8

--

Not Used

C3-9

PPL/WHT

Vehicle Speed Sensor (VSS) Input

C3-10

YEL/RED

AC On Signal

C3-11

BLK/WHT

Crank Signal

C3-12

BLK

Ignition Positive Voltage

C3-13

BLK

Engine Speed Output for Tachometer

C3-14

GRN/RED

Circuit Opening Relay Control

C3-15 to C3-16

--

Not Used

C3-17

WHT

Data Link Connector (DLC) Serial Data Line

C3-18 to C3-20

--

Not Used

C3-21

RED/BLU

AC Cutout Control

C3-22

BLU/BLK

Cooling Fan Control

Back View Of the PCM Connector C1 (4-Speed AT only)


Object Number: 621249  Size: CF

Connector Part Information

4-Speed AT only

31 Pin WHT Connector C1

Pin

Wire Color

Function

C1-1

YEL

Fuel Injector 1 Control

C1-2

BLK/RED

Fuel Injector 2 Control

C1-3

WHT

Fuel Injector 3 Control

C1-4

BLK

Fuel Injector 4 Control

C1-5 to C1-7

--

Not Used

C1-8

PPL

Shift Solenoid 1 Control

C1-9

--

Not Used

C1-10

RED/BLU

Ignition Trigger Signal Coil 1

C1-11

YEL/GRN

Ignition Trigger Signal Coil 2

C1-12

GRY

Ignition Trigger Signal Coil 3

C1-13

WHT

Ignition Trigger Signal Coil 4

C1-14 to C1-16

--

Not Used

C1-17

BLU/BLK

EVAP Canister Vent Solenoid Valve Control

C1-18

BLK/BLU

Idle Air Control (IAC) Valve Control

C1-19

BLU/YEL

Torque Converter Clutch (TCC) Solenoid Control

C1-20

BRN/YEL

Shift Solenoid 2 Control

C1-21

BRN

Ground

C1-22

RED

EVAP Pressure Switching Solenoid Control

C1-23

RED

Camshaft Position (CMP) Actuator Solenoid Valve Control Low

C1-24

BLK

Camshaft Position (CMP) Actuator Solenoid Valve Control High

C1-25

BLU/YEL

Ignition Fail Safe Input

C1-26

--

Not Used

C1-27

BLK

Knock Sensor (KS) Input

C1-28

LT GRN

AC Condenser Fan Control

C1-29 to C1-30

--

Not Used

C1-31

BRN

Ground

Back View Of the PCM Connector C2 (4-Speed AT only)


Object Number: 621254  Size: CF

Connector Part Information

4-Speed AT only

24 Pin WHT Connector C2

Pin

Wire Color

Function

C2-1

BLU/WHT

Mass Air Flow (MAF) Sensor Signal Low

C2-2

YEL

Throttle Position (TP) Sensor Ground

C2-3

PNK

Heated Oxygen Sensor (HO2S) 1 Heater Circuit Control

C2-4

BLU/BLK

EVAP Canister Purge Solenoid Valve Control

C2-5

--

Not Used

C2-6

PNK

Heated Oxygen Sensor (HO2S) 2 Heater Circuit Control

C2-7

BLU/BLK

AC Cooling Fan Relay Control

C2-8

BRN

Ground

C2-9

BLU

Fuel Tank Pressure Sensor Input

C2-10

--

Not Used

C2-11

GRN

Mass Air Flow (MAF) Sensor Signal High

C2-12

WHT

Heated Oxygen Sensor (HO2S) 1 Input

C2-13

--

Not Used

C2-14

WHT

Engine Coolant Temperature (ECT) Sensor Signal

C2-15

BLK

Camshaft Position (CMP) Sensor Input

C2-16

BLK

Crankshaft Position (CKP) Sensor Input

C2-17

BRN

Ground

C2-18

BRN

Sensor Ground

C2-19

--

Not Used

C2-20

RED

Heated Oxygen Sensor (HO2S) 2 Input

C2-21

--

Not Used

C2-22

YEL/BLK

Intake Air Temperature (IAT) Sensor Input

C2-23

LT GRN

Throttle Position (TP) Sensor Input

C2-24

WHT

CMP Sensor and CKP Sensor Ground

Back View Of the PCM Connector C3 (4-Speed AT only)


Object Number: 621256  Size: CF

Connector Part Information

4-Speed AT only

28 Pin WHT Connector C3

Pin

Wire Color

Function

C3-1

RED/WHT

Over-Drive (OD) Cut Signal

C3-2

RED/BLK

Park Neutral Position (PNP) Switch Position R Signal

C3-3

LT GRN/RED

Park Neutral Position (PNP) Switch Position 2 Signal

C3-4

LT GRN

OD Switch ON and OFF Signal

C3-5

BLU/WHT

Data Link Connector (Underhood) Diagnostic Request

C3-6

GRN/WHT

Brake Switch Signal

C3-7

--

Not Used

C3-8

YEL/BLU

Fuel Pump Cut-Off Signal (SIR SDM)

C3-9

--

Not Used

C3-10

BLK

Electrical Load Idle-Up Signal

C3-11

BLK/WHT

Crank Signal

C3-12

LT GRN/BLK

Park Neutral Position (PNP) Switch Low Signal

C3-13

BLK/WHT

Ignition Positive Voltage

C3-14

BLU/RED

Power Steering Pressure (PSP) Switch Signal

C3-15 to C3-18

--

Not Used

C3-19

LT GRN/BLU

OD Indicator Control

C3-20

GRN

Electrical Load Idle-Up Signal

C3-21

--

Not Used

C3-22

PPL/WHT

Vehicle Speed Sensor (VSS) Input

C3-23 to C3-26

--

Not Used

C3-27

BLK

Speed Sensor Signal

C3-28

--

Not Used

Back View Of the PCM Connector C4 (4-Speed AT only)


Object Number: 621257  Size: CF

Connector Part Information

4-Speed AT only

22 Pin WHT Connector C4

Pin

Wire Color

Function

C4-1

RED/WHT

Battery Positive Voltage

C4-2

--

Not Used

C4-3

GRN/RED

Circuit Opening Relay Control

C4-4 to C4-9

--

Not Used

C4-10

BLU/WHT

Idle Signal to Cruise Control

C4-11

WHT

Data Link Connector (DLC) Serial Data Line

C4-12

RED/BLU

AC Cut-Off Control

C4-13 to C4-14

--

Not Used

C4-15

RED/YEL

MIL Control

C4-16

BLK

Ignition Positive Voltage

C4-17

--

Not Used

C4-18

YEL/RED

AC ON Signal

C4-19 to C4-22

--

Not Used