GM Service Manual Online
For 1990-2009 cars only
Table 1: Back View of the Connector C1
Table 2: Back View of the Connector C2
Table 3: Back View of the Connector C3
Table 4: Back View of the Connector C4

Back View of the Connector C1


Object Number: 789637  Size: CF

Connector Part Information

    • 34-Pin
    • WHT

Pin

Wire Color

Function

1

YEL

Fuel Injector 1 Control

2

BLK

Fuel Injector 2 Control

3

WHT

Fuel Injector 3 Control

4

BLU

Fuel Injector 4 Control

5

BLK/BLU

Idle Air Control (IAC) Valve Control

6

WHT/BLK

Ground

7

WHT/BLK

Ground

8

RED/BLU

Ignition Trigger Signal Coil 1

9

YEL/GRN

Ignition Trigger Signal Coil 2

10

GRY

Ignition Trigger Signal Coil 3

11

WHT

Ignition Trigger Signal Coil 4

12

BLU/BLK

EVAP Canister Purge Solenoid Valve Control

13

YEL

AC Pressure Switch

14

BLK/YEL

Camshaft Position (CMP) Actuator Solenoid Valve Low Control

15

YEL

Camshaft Position (CMP) Actuator Solenoid Valve High Control

16

PNK

Line Pressure Control (PC) Solenoid Control Low*

17

RED/WHT

Line Pressure Control (PC) Solenoid Controll High*

18

YEL

5-Volt Reference Circuit

19

WHT

Engine Coolant Temperature (ECT) Sensor Input

20

YEL/BLK

Intake Air Temperature (IAT) Sensor Input

21

LT GRN

Throttle Position (TP) Sensor Input

22

--

Not Used

23

BLU/YEL

Ignition Fail Safe Input

24-25

--

Not Used

26

BLK

Camshaft Position (CMP) Sensor Input

27

BLK

Crankshaft Position (CKP) Sensor Input

28

BRN

Sensor Ground

29

--

Not Used

30

WHT/BLU

Transmission Fluid Temperature Sensor Input, with AWD Only*

31-33

--

Not Used

34

WHT

CMP Sensor and CKP Sensor Ground

*Automatic Transmission Only

Back View of the Connector C2


Object Number: 789639  Size: CF

Connector Part Information

    • 35-Pin
    • WHT

Pin

Wire Color

Function

1

BLK

Knock Sensor (KS) Signal High

2

WHT

Knock Sensor (KS) Signal Low

3

--

Not Used

4

PNK

Heated Oxygen Sensor (HO2S) 1 Heater Circuit Control

5

WHT/BLK

Ground

6

--

Not Used

7

BRN

Ground

8

RED

Ignition Positive Voltage*

9

BLK

Crank Signal

10-11

--

Not Used

12

BLU/ORN

Shift Solenoid ST Control, with AWD Only*

13

BLU/WHT

Torque Converter Clutch (TCC) Solenoid Control*

14

BLU

Shift Solenoid (SS) 2 Control*

15

RED/YEL

Shift Solenoid (SS) 1 Control*

16-20

--

Not Used

21

WHT

Heated Oxygen Sensor (HO2S) 2 Input

22

--

Not Used

23

BLK

Heated Oxygen Sensor (HO2S) 1 Input

24

GRN

Mass Air Flow (MAF) Sensor Signal High

25-26

--

Not Used

27

WHT

Input Shaft Speed Sensor Reference High, with AWD Only*

28

WHT/BLK

Ground

29

BLU/RED

Power Steering Pressure (PSP) Switch Input

30-31

--

Not Used

32

BLU/WHT

Mass Air Flow (MAF) Sensor Signal Low

33-34

--

Not Used

35

BLK

Intput Shaft Speed Sensor Reference Low, with AWD Only*

*Automatic Transmission Only

Back View of the Connector C3


Object Number: 789640  Size: CF

Connector Part Information

    • 35-Pin
    • WHT

Pin

Wire Color

Function

1

BLU

EVAP Canister Vent Solenoid Valve Control

2

YEL/BLK

AC Compressor Clutch Relay Control

3

--

Not Used

4

PNK/BLK

Heated Oxygen Sensor (HO2S) 2 Heater Circuit Control

5-6

--

Not Used

7

LT GRN

Overdrive (OD) Indicator Control*

8

LT GRN/BLK

Park Neutral Position (PNP) Switch L Position Signal*

9

LT GRN

Park Neutral Position (PNP) Switch 2 Position Signal*

10

BLU

Park Neutral Position (PNP) Switch D Position Signal*

11

RED/BLK

Park Neutral Position (PNP) Switch R Position Signal*

12-13

--

Not Used

14

YEL/RED

Engine Coolant Temperature Gage Output

15-16

--

Not Used

17

PPL/WHT

Vehicle Speed Sensor (VSS) Input

18

RED/YEL

Over-Drive (OD) Cut Signal, with Cruise Control*

19

GRN/WHT

Brake Switch Signal

20-28

--

Not Used

29

GRN/BLK

Overdrive (OD) Switch Signal*

30

--

Not Used

31

YEL

AC Request Signal

32

BLK/BLU

Evaporator Temperature Sensor Input

33

GRN/WHT

AC On Signal

34-35

--

Not Used

*Automatic Transmission Only

Back View of the Connector C4


Object Number: 789641  Size: CF

Connector Part Information

    • 31-Pin
    • WHT

Pin

Wire Color

Function

1

BLK

Ignition Positive Voltage

2

--

Not Used

3

RED/WHT

Battery Voltage

4

RED

EVAP Pressure Switching Solenoid Control

5

BLK

Engine Speed Output for Tachometer

6

GRN

Fan 1 Relay Control

7

GRN/BLK

Fan 2 Relay Control

8-9

--

Not Used

10

GRN/RED

Circuit Opening Relay Control

11

RED/YEL

MIL Control

12

GRN

Electrical Load Idle-Up Signal, Tail Lamps

13

WHT

Electrical Load Idle-Up Signal, Rear Defogger

14

YEL

Supplemental Inflatable Restraint (SIR) System Signal

15

--

Not Used

16

BLU/WHT

Cruise Control Idle

17

--

Not Used

18

BLU/RED

Serial Data

19

PNK

Data Link Connector (DLC)

20

PNK/BLK

Diagnostic Request Circuit

21

BLU

Fuel Tank Pressure (FTP) Sensor Input

22-31

--

Not Used

*Automatic Transmission Only