GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC C-Series Medium Duty Truck B7 🢒 Brakes 🢒 Antilock Brake System 🢒 Instrument Panel, Gages, and Console Connector End Views
Table 1: Ammeter
Table 2: Automatic Transmission (AT) FluidTemperature Gauge
Table 3: Automatic Transmission (AT) Fluid Temperature Gauge Sensor
Table 4: Automatic Transmission (AT) Shift Selector Control (Gasoline and GM Diesel)
Table 5: Automatic Transmission (AT) Shift Selector Control (Cat® Diesel)
Table 6: Driver Information Center (C1) (Cat® Diesel)
Table 7: Driver Information Center (C2) (Cat® Diesel)
Table 8: Driver Information Center (C1) (Gasoline)
Table 9: Driver Information Center (C2) (Gasoline)
Table 10: Driver Information Center (C1) (GM Diesel)
Table 11: Driver Information Center (C2) (GM Diesel)
Table 12: Engine Coolant Temperature (ECT) Gauge Sensor (Gasoline Engine)
Table 13: Engine Coolant Temperature (ECT) Switch (Cat® Diesel)
Table 14: Engine Coolant Temperature (ECT) Gauge Sensor (Cat® Diesel)
Table 15: Engine Coolant Temperature (ECT) Gauge Sensor (GM Diesel)
Table 16: Engine Oil Pressure (EOP) Gauge Sensor (Cat® Diesel)
Table 17: Engine Oil Pressure (EOP) Indicator Switch (Cat® Diesel)
Table 18: Fuel Pump Switch and Engine Oil Pressure (EOP) Gauge Sensor (Gasoline)
Table 19: Fuel Pump Switch and Engine Oil Pressure (EOP) Gauge Sensor (GM Diesel)
Table 20: Hazard Warning Switch
Table 21: Hazard Warning Name Plate
Table 22: Headlamps Dimmer Switch
Table 23: Headlamps Switch
Table 24: Hi Idle Switch (Cat® Diesel)
Table 25: Hi Idle Switch (Gasoline)
Table 26: Hi Idle Switch (GM Diesel)
Table 27: Hourmeter
Table 28: IP Lamps Dimmer Control
Table 29: Instrument Panel Cluster (IPC)
Table 30: Low Air Pressure Switch
Table 31: Low Engine Coolant Level Indicator Switch
Table 32: Multifunction Alarm Module (MFAM) (Cat® Diesel)
Table 33: Multifunction Alarm Module (MFAM) (Gasoline)
Table 34: Multifunction Alarm Module (MFAM) (GM Diesel)
Table 35: Multifunction Alarm Module (MFAM) w/Automatic Engine Shutdown C2 (Cat® Diesel)
Table 36: Turn Signal Switch

Ammeter


Object Number: 62456 Size: CH

Connector Part Information
    • 12064752
    • 6 Way F Metri-Pack 280 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A

GRY

8

Instrument Panel Lamp Feed

B

BLK

150

Ground

C

WHT

2084

Generator Feed-Ammeter

D

GRY

2083

Starter Feed-Ammeter

E-F

--

--

Not Used

Automatic Transmission (AT) FluidTemperature Gauge


Object Number: 40422 Size: CH

Connector Part Information
    • 12064762
    • 6 Way F Metri-Pack 150 Series (GRY)

Pin

Wire Color

Circuit No.

Function

A

BRN

341

Fuse Output-Ignition

B

--

--

Not Used

C

TAN/WHT

585

Transmission Oil Temperature Sensor Signal

D

BLK

250

Ground

E

--

--

Not Used

F

GRY

8

Instrument Panel Lamp Feed

Automatic Transmission (AT) Fluid Temperature Gauge Sensor


Object Number: 68719 Size: CH

Connector Part Information
    • 12162198
    • 2 Way F Metri-Pack 150 Series, Sealed (GRY)

Pin

Wire Color

Circuit No.

Function

A

TAN/WHT

585

Transimssion Oil Temperature Sensor Signal

B

BLK

150

Ground

Automatic Transmission (AT) Shift Selector Control (Gasoline and GM Diesel)


Object Number: 62463 Size: CH

Connector Part Information
    • 12064766
    • 8 Way F Metri-Pack 150 Series (BLU)

Pin

Wire Color

Circuit No.

Function

A

GRY

8

Instrument Panel Lamp Feed

B

ORN/BLK

1786

Transmission Park/Neutral Signal

C-E

--

--

Not Used

F

BLK/WHT

451

Engine Control Module Ground

G

--

--

Not Used

H

BLK

250

Ground

Automatic Transmission (AT) Shift Selector Control (Cat® Diesel)


Object Number: 62463 Size: CH

Connector Part Information
    • 12064766
    • 8 Way F Metri-Pack 150 Series (BLU)

Pin

Wire Color

Circuit No.

Function

A

GRA

8

Instrument Panel Lamp Feed

B

ORN/BLK

1786

Transmission Park/Neutral Signal

C-E

--

--

Not Used

F

PNK

39

Fuse Output-Ignition

G

--

--

Not Used

H

BLK

250

Ground

Driver Information Center (C1) (Cat® Diesel)


Object Number: 231421 Size: CH

Connector Part Information
    • 12052413
    • 11 Way F Micro-Pack 100 Series (BLU)

Pin

Wire Color

Circuit No.

Function

A

--

--

Not Used

B

BLK

250

Ground

C

--

--

Not Used

D

YEL/BLK

1471

Brake Warning Indicator Lamp Feed-Secondary

E

--

--

Not Used

F

TAN/WHT

33

Brake Warning IndicatorLamp Output

G

WHT/BLK

235

Bulb Test Signal

H

LT BLU

1134

Park Brake Switch Signal

J

PNK

39

Fuse Output-Ignition

K

LT  GRN/BLK

592

Daytime Running Lamp Relay Output-Coil

L

--

--

Not Used

Driver Information Center (C2) (Cat® Diesel)


Object Number: 231421 Size: CH

Connector Part Information
    • 12084134
    • 11 Way F Micro-Pack 100 Series (BRN)

Pin

Wire Color

Circuit No.

Function

A

PNK

39

Fuse Output-Ignition

B

LT GRN

867

ABS Failure Indicator Lamp Output

C

BRN/WHT

419

Check Engine Indicator Lamp Output

D

--

--

Not Used

E

RED

2013

High Idle Indicator Lamp Output

F-G

--

--

Not Used

H

BRN

199

Speaker Feed-Left Rear

J

--

--

Not Used

K

TAN/WHT

33

Brake Warning Indicator Lamp Output

L

YEL/BLK

68

Low Coolant Level Indicator Lamp Output

Driver Information Center (C1) (Gasoline)


Object Number: 231421 Size: CH

Connector Part Information
    • 12052413
    • 11 Way F Micro-Pack 100 Series (BLU)

Pin

Wire Color

Circuit No.

Function

A

--

--

Not Used

B

BLK

250

Ground

C

--

--

Not Used

D

YEL/BLK

1471

Brake Warning Indicator Lamp Feed-Secondary

E

--

--

Not Used

F

TAN/WHT

33

Brake Warning Indicator Lamp Output

G

WHT/BLK

235

Bulb Test Signal

H

LT BLU

1134

Park Brake Switch Signal

J

PNK

39

Fuse Output-Ignition

K

LT  GRN/BLK

592

Daytime Running Lamp Relay Output-Coil

L

--

--

Not Used

Driver Information Center (C2) (Gasoline)


Object Number: 231421 Size: CH

Connector Part Information
    • 12084134
    • 11 Way F Micro-Pack 100 Series (BRN)

Pin

Wire Color

Circuit No.

Function

A

PNK

39

Fuse Output-Ignition

B

LT GRN

867

ABS Failure Indicator Lamp Output

C

BRN/WHT

419

Check Engine Indicator Lamp Output

D

DK BLU

1938

Engine Overspeed Indicator Lamp Output

E

RED

2013

High Idle Indicator Lamp Output

F-J

--

--

Not Used

K

TAN/WHT

33

Brake Warning Indicator Lamp Output

L

--

--

Not Used

Driver Information Center (C1) (GM Diesel)


Object Number: 231421 Size: CH

Connector Part Information
    • 12052413
    • 11 Way F Micro-Pack 100 Series (BLU)

Pin

Wire Color

Circuit No.

Function

A

DK BLU

507

Glow Plug Indicator Lamp Signal

B

BLK

250

Ground

C

--

--

Not Used

D

YEL/BLK

1471

Brake Warning Indicator Lamp Feed-Secondary

E

YEL/BLK

508

Water In Fuel Indicator Lamp Output

F

YEL/BLK

508

Water In Fuel Indicator Lamp Output

G

WHT/BLK

235

Bulb Test Signal

H

LT BLU

1134

Park Brake Switch Signal

J

PNK

39

Fuse Output-Ignition

K

LT  GRN/BLK

592

Daytime Running Lamp Relay Output-Coil

L

--

--

Not Used

Driver Information Center (C2) (GM Diesel)


Object Number: 231421 Size: CH

Connector Part Information
    • 12084134
    • 11 Way F Micro-Pack 100 Series (BRN)

Pin

Wire Color

Circuit No.

Function

A

PNK

39

Fuse Output-Ignition

B

LT GRN

867

ABS Failure Indicator Lamp Output

C

BRN/WHT

419

Check Engine Indicator Lamp Output

D-E

--

--

Not Used

F

WHT/BLK

176

Service Throttle Soon Indicator Lamp Output

G

PNK

39

Fuse Output-Ignition

H

--

--

Not Used

J

PNK

39

Fuse Output-Ignition

K

TAN/WHT

33

Brake Warning Indicator Lamp Output

L

YEL/BLK

68

Low Coolant Level Indicator Lamp Output

Engine Coolant Temperature (ECT) Gauge Sensor (Gasoline Engine)


Object Number: 62485 Size: CH

Connector Part Information
    • 12078090
    • 3 Way F Metri-Pack 150 Series, Sealed (BLK)

Pin

Wire Color

Circuit No.

Function

A

BLK

452

Sensor Return

B

YEL

410

Coolant Temperature Sensor Signal

C

DK GRN

135

Coolant Temperature Sensor Signal

Engine Coolant Temperature (ECT) Switch (Cat® Diesel)


Object Number: 236598 Size: CH

Connector Part Information
    • 12052641
    • 2 Way F Metri-Pack 150 Series, Sealed (BLK)

Pin

Wire Color

Circuit No.

Function

A

BRN

1675

Check Gauges Signal

B

--

--

Not Used

Engine Coolant Temperature (ECT) Gauge Sensor (Cat® Diesel)


Object Number: 68719 Size: CH

Connector Part Information
    • 12162198
    • 2 Way F Metri-Pack 150 Series, Sealed (GRY)

Pin

Wire Color

Circuit No.

Function

A

DK GRN

135

Coolant Temperature Sensor Signal

B

BLK

150

Ground

Engine Coolant Temperature (ECT) Gauge Sensor (GM Diesel)


Object Number: 333039 Size: CH

Connector Part Information
    • 12089499
    • 2 Way F Metri-Pack 150 Series, Sealed (BLU)

Pin

Wire Color

Circuit No.

Function

A

DK GRN

35

Coolant Temperature Indicator Lamp Output

B

--

--

Not Used

Engine Oil Pressure (EOP) Gauge Sensor (Cat® Diesel)


Object Number: 236406 Size: CH

Connector Part Information
    • 12065400
    • 2 Way F Metri-Pack 150 Series, Sealed (LT GRN)

Pin

Wire Color

Circuit No.

Function

A

TAN/WHT

331

Oil Pressure Sensor Signal

B

BLK

150

Ground

Engine Oil Pressure (EOP) Indicator Switch (Cat® Diesel)


Object Number: 236480 Size: CH

Connector Part Information
    • 12065299
    • 1 Way F Metri-Pack 150 Series, Sealed (GRY)

Pin

Wire Color

Circuit No.

Function

A

TAN/BLK

231

Oil Pressure Switch Signal

Fuel Pump Switch and Engine Oil Pressure (EOP) Gauge Sensor (Gasoline)


Object Number: 258230 Size: CH

Connector Part Information
    • 12065298
    • 4 Way F Metri-Pack 150 Series, Sealed (BLK)

Pin

Wire Color

Circuit No.

Function

A

TAN/WHT

331

Oil Pressure Sensor Signal

B

BLK

150

Ground

C

ORN

740

Fuse Output Battery Type III Fuse

D

GRY

120

Fuel Pump Motor Feed

Fuel Pump Switch and Engine Oil Pressure (EOP) Gauge Sensor (GM Diesel)


Object Number: 39663 Size: CH

Connector Part Information
    • 12065401
    • 3 Way F Metri-Pack 150 Series, Sealed (GRY)

Pin

Wire Color

Circuit No.

Function

A

TAN

31

Oil Pressure Indicator Lamp Output

B

--

--

Not Used-Sealed

C

GRY

120

Fuel Pump Motor Feed

D

ORN

440

Fuse Output Battery Type III Fuse

Hazard Warning Switch


Object Number: 288397 Size: CH

Connector Part Information
    • 12034482
    • 6 Way F Metri-Pack 280 Series, (GRY)

Pin

Wire Color

Circuit No.

Function

A

BRN

27

Hazard Flasher Output

B

YEL

18

Stop/Turn Lamp Feed Left Rear

C

DK BLU

15

Turn Signal Lamp Feed Right Front

D

DK GRN

19

Stop/Turn Lamp Feed Right Rear

E

LT BLU

14

Turn Signal Lamp Feed Left Front

F

BLK

150

Ground

Hazard Warning Name Plate


Object Number: 35441 Size: CH

Connector Part Information
    • 12047663
    • 2 Way M Metri-Pack 150 Series, (BLK)

Pin

Wire Color

Circuit No.

Function

A

BLK

150

Ground

B

GRY

8

Instrument Panel Lamp Feed

Headlamps Dimmer Switch


Object Number: 332023 Size: CH

Connector Part Information
    • 08917693
    • 4 Way F 56 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A

LT GRN

11

High Beam Headlamp Feed

B

--

--

Not Used

C

PPL

544

Daytime Running Lamp Relay Feed N.C. Contact

D

YEL

10

Headlamp Switch Output

Headlamps Switch


Object Number: 39734 Size: CH

Connector Part Information
    • 12034061
    • 6 Way F Metri-Pack 480 Series, (NAT)

Pin

Wire Color

Circuit No.

Function

A

LT BLU

13

Headlamp Switch Output Park Lamps

B

YEL

634

Daytime Running Lamp Diode Feed

C

RED

1042

Fuse Output Battery Type II Fuse

D

YEL

10

Headlamp Switch Output

E

ORN

1040

Fuse Output Battery Type III Fuse

F

--

--

Not Used

Hi Idle Switch (Cat® Diesel)


Object Number: 95782 Size: CH

Connector Part Information
    • 12052833
    • 2 Way M Metri-Pack 150 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A

BLK

808

Sensor Return

B

DK GRN

534

High Idle Switch Output

Hi Idle Switch (Gasoline)


Object Number: 95782 Size: CH

Connector Part Information
    • 12052833
    • 2 Way M Metri-Pack 150 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A

DK GRN

534

High Idle Switch Output

B

BLK/WHT

451

Engine Control Module Ground

Hi Idle Switch (GM Diesel)


Object Number: 62432 Size: CH

Connector Part Information
    • 12041429
    • 5 Way F Metri-Pack 280 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A

BRN

341

Fuse Output-Ignition

B

DK GRN

534

High Idle Switch Output

C

--

--

Not Used

D

DK GRN

534

High Idle Switch Output

E

BLK/WHT

451

Engine Control Module Ground

Hourmeter


Object Number: 130635 Size: CH

Connector Part Information
    • 12045813
    • 4 Way F Metri-Pack 150 Series, (NAT)

Pin

Wire Color

Circuit No.

Function

A

YEL

53

Fuse Output Generator Tachomeater Pulse Type III Fuse

B

--

--

Not Used

C

BLK

150

Ground

D

--

--

Not Used

IP Lamps Dimmer Control


Object Number: 38618 Size: CH

Connector Part Information
    • 12034060
    • 4 Way F Metri-Pack 480 Series, (NAT)

Pin

Wire Color

Circuit No.

Function

A

LT BLU

13

Headlamp Switch Output Park Lamps

B-C

--

--

Not Used

D

GRY

8

Instrument Panel Lamp Feed

Instrument Panel Cluster (IPC)


Object Number: 223224 Size: CH

Connector Part Information
    • 12040744
    • 32 Way F Micro-Pack 100 Series (BLK)

Pin

Wire Color

Circuit No.

Function

1-8

--

--

Not Used

9

PNK

39

Fuse Output-Ignition

10-14

--

--

Not Used

15

BLK

250

Ground

16

DK BLU

15

Turn Signal Lamp Feed-Right Front

17

LT BLU

14

Turn Signal Lamp Feed-Left Front

18

LT GRN

11

High Beam Headlamp Feed

19

BRN

25

Charge Indicator Lamp Output

20

BLK

250

Ground

21

TAN/WHT

331

Oil Pressure Sensor Signal

22

DK GRN

135

Coolant Temperature Sensor Signal

23

--

--

Not Used

24

GRA

8

Instrument Panel Lamp Feed

25

BLK

250

Ground

26

LT BLU

1377

Check Gauges Indicator Lamp Output

27

PNK

39

Fuse Output-Ignition

28

DK  GRN/WHT

817

Vehicle Speed Sensor-4000 Pulses Per Mile (GM Diesel Engine)

28

DK GRN

389

Vehicle Speed Sensor-4000 Pulses Per Mile

29

BLK/WHT

451

Engine Control Module Ground

30

PPL

30

Fuel Gauge Sensor Signal

31

--

--

Not Used

32

PNK

39

Fuse Output-Ignition

33

YEL

53

Fuse Output-Generator-Tachometer Pulse

33

WHT

121

Tachometer Signal (Gasoline Engine)

34

--

--

Not Used

Low Air Pressure Switch


Object Number: 236406 Size: CH

Connector Part Information
    • 12065400
    • 2 Way F Metri-Pack 150 Series, Sealed (GRN)

Pin

Wire Color

Circuit No.

Function

A

BLK

150

Ground

B

TAN/WHT

33

Brake Warning Indicator Lamp Output

Low Engine Coolant Level Indicator Switch


Object Number: 236598 Size: CH

Connector Part Information
    • 12052641
    • 2 Way F Metri-Pack 150 Series, Sealed (BLK)

Pin

Wire Color

Circuit No.

Function

A

LT GRN

1478

Low Coolant Sensor Signal

B

BLK

150

Ground

Multifunction Alarm Module (MFAM) (Cat® Diesel)


Object Number: 73152 Size: CH

Connector Part Information
    • 12084944
    • 16 Way F Micro-Pack 100 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A1

LT  BLU/BLK

1928

Brake Booster Fluid Flow Switch Feed

A2

YEL

53

Fuse Output-Generator-Tachometer Pulse

A3

LT BLU

20

Stop Lamp Feed

A4

ORN/BLK

434

Transmission Mounted Neutral Safety Switch Signal

A5

PNK

39

Fuse Output-Ignition

A6

TAN/WHT

33

Brake Warning Indicator Lamp Output

A7

TAN/BLK

231

Oil Pressure Switch Signal

A8

BLK

150

Ground

B1

LT GRN

1478

Low Coolant Sensor Signal

B2

YEL/BLK

68

Low Coolant Level Indicator Lamp Output

B3

YEL/BLK

1471

Brake Warning Indicator Lamp Feed-Seconday

B4

GRY

847

Brake Pedal Switch Output-Extended Travel

B5

TAN/WHT

33

Brake Warning Indicator Lamp Output

B6

BRN

1675

Check Gauges Signal

B7

LT BLU

1377

Check Gauges Indicator Lamp Output

B8

ORN

1740

Fuse Output-Battery

Multifunction Alarm Module (MFAM) (Gasoline)


Object Number: 73152 Size: CH

Connector Part Information
    • 12084944
    • 16 Way F Micro-Pack 100 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A1

LT  BLU/BLK

1928

Brake Booster Fluid Flow Switch Feed

A2

YEL

53

Fuse Output-Generator-Tachometer Pulse

A3

LT BLU

20

Stop Lamp Feed

A4

ORN/BLK

434

Transmission Mounted Neutral Safety Switch Signal

A5

PNK

39

Fuse Output-Ignition

A6

TAN/WHT

33

Brake Warning Indicator Lamp Output

A7

--

--

Not Used

A8

BLK

150

Ground

B1

BLK

150

Ground

B2

--

--

Not Used

B3

YEL/BLK

1471

Brake Warning Indicator Lamp Feed-Seconday

B4

GRY

847

Brake Pedal Switch Output-Extended Travel

B5

TAN/WHT

33

Brake Warning Indicator Lamp Output

B6

--

--

Not Used

B7

LT BLU

1377

Check Gauges Indicator Lamp Output

B8

ORN

1740

Fuse Output-Battery

Multifunction Alarm Module (MFAM) (GM Diesel)


Object Number: 73152 Size: CH

Connector Part Information
    • 12084944
    • 16 Way F Micro-Pack 100 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A1

LT  BLU/BLK

1928

Brake Booster Fluid Flow Switch Feed

A2

YEL

53

Fuse Output-Generator-Tachometer Pulse

A3

LT BLU

20

Stop Lamp Feed

A4

ORN/BLK

434

Transmission Mounted Neutral Safety Switch Signal

A5

PNK

39

Fuse Output-Ignition

A6

TAN/WHT

33

Brake Warning Indicator Lamp Output

A7

--

--

Not Used

A8

BLK

150

Ground

B1

LT GRN

1478

Low Coolant Sensor Signal

B2

YEL/BLK

68

Low Coolant Level Indicator Lamp Output

B3

YEL/BLK

1471

Brake Warning Indicator Lamp Feed-Seconday

B4

GRY

847

Brake Pedal Switch Output-Extended Travel

B5

--

--

Not Used

B6

BRN

1675

Check Gauges Signal

B7

LT BLU

1377

Check Gauges Indicator Lamp Output

B8

ORN

1740

Fuse Output-Battery

Multifunction Alarm Module (MFAM) w/Automatic Engine Shutdown C2 (Cat® Diesel)


Object Number: 280782 Size: CH

Connector Part Information
    • 12064760
    • 4 Way F Metri-Pack 150 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A

BLK

850

Ground

B

BLK

150

Ground

C

--

--

Not Used

D

GRY

535

Coolant Temperature Switch Output

Turn Signal Switch


Object Number: 222621 Size: CH

Connector Part Information
    • 12004147
    • 11 Way F Pack-Con Series 1 (BLK)

Pin

Wire Color

Circuit No.

Function

D-F

--

--

Not Used

G

BLK

28

Horn Relay Output Coil

H

LT BLU

14

Turn Signal Lamp Feed Left Front

J

DK BLU

15

Turn Signal Lamp Feed Right Front

K

--

--

Not Used

L

PPL

16

Turn Signal Flasher Output

M

YEL

18

Stop/Turn Lamp Feed Left Rear

N

DK GRN

19

Stop/Turn Lamp Feed Right Rear

P

--

--

Not Used