GM Service Manual Online
For 1990-2009 cars only
Table 1: Engine Control Module (ECM) C1
Table 2: Engine Control Module (ECM) C2
Table 3: Engine Control Module (ECM) C3

Engine Control Module (ECM) C1


Object Number: 1587827  Size: CH

Connector Part Information

    • 9123-7148
    • 56-Way F (BU)

Pin

Wire Color

Circuit No.

Function

1

TN/BK

2500

High Speed GMLAN Serial Data Bus+

2

TN

2501

High Speed GMLAN Serial Data Bus-

3

--

--

Not Used

4

BN/WH

419

Check Engine Indicator Lamp Output

5-6

--

--

Not Used

7

BN

1271

Electronic Throttle Pedal Position Return 1

8

PU

1272

Electronic Throttle Pedal Position Return 2

9

--

--

Not Used

10

BN

5069

Engine Control Relay Coil Control

11-12

--

--

Not Used

13

YE

447

Starter Relay Output - Coil

14

PK

439

Ignition 1 Voltage

15-17

--

--

Not Used

18

YE

1843

Accessory Voltage

19

OG

300

Ignition 3 Voltage

20

OG/BK

740

Battery Positive Voltage

21

PU/WH

5197

VSS Signal

22

BU

1161

Electronic Throttle Pedal Position Signal 1

23

--

--

Not Used

24

GN

890

Fuel Tank Pressure Sensor Signal

25

--

--

Not Used

26

GN/BK

380

A/C Refrigerant Pressure Sensor Signal

27-28

--

--

Not Used

29

TN

1274

Electronic Throttle Pedal Position 5-Volt Reference 2

30

GN

2700

A/C Refrigerant Pressure Sensor Signal 5-Volt Reference

31

GY

2709

Fuel Tank Pressure Sensor 1, 5-Volt Reference

32

BU/RD

20

Stop Lamp Switch Signal

33-34

--

--

Not Used

35

WH/BK

1164

Electronic Throttle Pedal Position 5 Volt Reference 1

36

OG/BK

335

Low Speed Cooling Fan Relay Control

37

PU

30

Fuel Gage Sensor Signal

38

GY

847

Extended Travel Brake Switch Signal

39-40

--

--

Not used

41

L-BU

1162

Electronic Throttle Pedal Position 2

42

YE

1652

Reverse Lockout Solenoid Control

43

PU/WH

379

CPP Switch Signal

44

--

--

Not Used

45

GN/WH

465

Fuel Pump Relay Feed - Coil

46

BN

86

Cruise Control Release Signal

47

--

--

Not Used

48

BN

121

Tachometer Signal

49-50

--

--

Not Used

51

GN/BU

275

Park/Neutral Position Switch Park Signal

52

PU

5

Crank Voltage

53-54

--

--

Not Used

55

TN

5514

A/C Refrigerant Pressure Sensor Signal

56

BU/WH

473

High Speed Cooling Fan Relay Control

Engine Control Module (ECM) C2


Object Number: 1587818  Size: CH

Connector Part Information

    • 9123-7131
    • 73-Way F (BK)

Pin

Wire Color

Circuit No.

Function

1

L-GN/RD

3113

HO2S Bank 2 Sensor 1 Heater Control

2

BK/WH

3212

HO2S Bank 1 Sensor 1 Heater Control

3

--

--

Not Used

4

L-GN

878

Fuel Injector 8 Control

5

BU

1744

Fuel Injector 1 Control

6

GN

1745

Fuel Injector 2 Control

7

PK/BK

877

Fuel Injector 7 Control

8

BN/YE

844

Fuel Injector 4 Control

9

PU

1746

Fuel Injector 3 Control

10

GY

845

Fuel Injector 5 Control

11-12

--

--

Not Used

13

YE

846

Fuel Injector 6 Control

14

L-BU/BK

574

Low Reference

15

RD/WH

632

Low Reference

16

BN

2129

Low Reference

17-19

--

--

Not Used

20

BK

469

MAP Sensor - Return

21

GN

470

Low Reference

22-23

--

--

Not Used

24

BN/WH

331

Engine Oil Pressure Signal

25

--

--

Not Used

26

BN

633

CMP Sensor

27-28

--

--

Not Used

29

PU

486

Throttle Position Sensor 2 Signal

30

--

--

Not Used

31

GN

485

Throttle Position Sensor 1 Signal

32-33

--

--

Not Used

35

PU/WH

2704

MAP Sensor 5-Volt Reference

36

BN/WH

1704

Low Reference

37

BU/YE

596

Reference Voltage 5-Volt Reference

38-40

--

--

Not Used

41

L-BU/BK

1688

5-Volt Reference

42

--

--

Not Used

43

L-BU/WH

2867

12-Volt Reference Voltage

44

WH/BK

631

Low Coolant Level Indicator Signal

45

GY

23

Generator Field Duty Cycle Signal

46

L-GN

432

MAP Sensor Signal

47

--

--

Not Used

48

PU

1665

HO2S High Signal Bank 1 Sensor 1

49

BU/BK

1664

HO2S Low Signal Bank 1 Sensor 1

50

GN/YE

428

EVAP Canister Purge Solenoid Control

51

GY

1666

HO2S High Signal Bank 2 Sensor 1

52

GY/BK

2761

Low Reference

53

YE

2127

Ignition Coil 7 Control

54

WH

1310

EVAP Canister Vent Solenoid Control

55

YE

410

ECT Sensor Signal 5-Volt Reference

56

OG

225

Generator Turn On Signal

57

L-GN

2126

Ignition Coil 6 Control

58

WH

2124

Ignition Coil 4 Control

59

GN

2125

Ignition Coil 5 Control

60

BN

582

TAC Motor Control - 2

61

BU

2123

Ignition Coil 3 Control

62

BU

573

CKP Sensor Signal

63

YE

581

TAC Motor Control - 1

64

PU

2130

Low Reference

65

L-BU

2128

Ignition Coil 8 Control

66

YE/BK

2122

Ignition Coil 2 Control

67

--

--

Not Used

68

BU

496

Knock Sensor 1 Signal

69

GY

2303

Knock Sensor 1 Return

70

GY/BK

1667

HO2S Low Signal Bank 2 Sensor 1

71

GY

1716

Knock Sensor 2 Return

72

L-BU

1876

Knock Sensor 2 Signal

73

BK/RD

450

Ground

Engine Control Module (ECM) C3


Object Number: 1587827  Size: CH

Connector Part Information

    • 9123-7148
    • 56-Way F (GY)

Pin

Wire Color

Circuit No.

Function

1

--

--

Not Used

2

L-BU

3223

HO2S Bank 1 Sensor 2 Heater Control

3

RD/WH

3122

HO2S Bank 2 Sensor 2 Heater Control

4-10

--

--

Not Used

11

BN/WH

492

MAF Sensor Signal

12-17

--

--

Not Used

18

BN/RD

1669

HO2S Low Signal Bank 1 Sensor 2

19

PU/WH

1668

HO2S High Signal Bank 1 Sensor 2

20

PU/BK

1670

HO2S High Signal Bank 2 Sensor 2

21

BN/BU

1671

HO2S Low Signal Bank 2 Sensor 2

22

OG/BK

1786

Park/Neutral Signal

23

--

--

Not Used

24

BK

2759

Low Reference

25-33

--

--

Not Used

34

BK

472

IAT Sensor Signal

35-42

--

--

Not Used

44

BN/OG

401

VSS Low Signal

45

BU/WH

400

VSS High Signal

46-47

--

--

Not Used

48

GY

587

Skip Shift Solenoid Control

49

BK

2759

Low Reference

50

--

--

Not Used

51

L-GN/BK

459

A/C Compressor Clutch Relay Control

52-56

--

--

Not Used