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

Engine Control Module (ECM) C1


Object Number: 1673474  Size: CH

Connector Part Information

  • OEM: 13583475
  • Service: 88988373
  • Description: 56-Way F MX123 Series (BK)

Terminal Part Information

  • Pins: 7, 9, 12, 16, 18- 20, 25, 29, 31- 37, 39, 40, 44, 46- 49, 53-56
  • Terminal/Tray: See Terminal Repair Kit
  • Core/Insulation Crimp: See Terminal Repair Kit
  • Release Tool/Test Probe: See Terminal Repair Kit

Engine Control Module (ECM) C1

Pin

Wire Color

Circuit No.

Function

1-6

--

--

Not Used

7

WH

17

Stop Lamp Switch Signal

8

--

--

Not Used

9

BK

2759

Low Reference

10-11

--

--

Not Used

12

BN/WH

419

MIL Control

13

D-GN/WH

465

Fuel Pump Relay Control

14-15

--

--

Not Used

16

D-GN

1049

ECM Class 2 Serial Data

17

--

--

Not Used

18

BN

1141

Accessory Voltage

19

PK

439

Ignition 1 Voltage

20

OG

540

Battery Positive Voltage

21-24

--

--

Not Used

25

WH

121

Engine Speed Signal

26-28

--

--

Not Used

29

GY

1884

Cruise Control Switch Signal

30

--

--

Not Used

31

YE/BK

6032

Low Reference

32

GY

6031

5-Volt Reference 2

33

WH/BK

1164

5-Volt Reference 2

34

GY

2709

5-Volt Reference 1

35

TN

1274

5-Volt Reference 1

36

BN

1271

Low Reference

37

PU

1272

Low Reference

38

--

--

Not Used

39

D-GN

389

Vehicle Speed Signal

40

BN

5069

Powertrain Relay Control

41-43

--

--

Not Used

44

PU

1589

Fuel Level Sensor Signal

45

--

--

Not Used

46

OG

6030

Brake Booster Vacuum Signal

47

D-BU

1161

APP Sensor 1 Signal

48

D-GN

890

Fuel Tank Pressure Sensor Signal

49

L-BU

1162

APP Sensor 2 Signal

50-52

--

--

Not Used

53

D-GN/WH

459

A/C Compressor Clutch Relay Control

54

D-BU

473

High Speed Cooling Fan Relay Control

55

WH

1310

EVAP Canister Vent Solenoid Control

56

YE/BK

625

Starter Enable Relay Control

Engine Control Module (ECM) C2


Object Number: 1673472  Size: CH

Connector Part Information

  • OEM: 13574286
  • Service :88988931
  • Description: 73-Way F MX123 34566 Series (BK)

Terminal Part Information

  • Pins: 1-9, 11-13, 16-19, 23, 24, 27, 29, 32-35, 39, 40, 42-44, 48, 49, 52-55, 59, 60, 62-64, 66-73
  • Terminal/Tray: See Terminal Repair Kit
  • Core/Insulation Crimp: See Terminal Repair Kit
  • Release Tool/Test Probe: See Terminal Repair Kit

Engine Control Module (ECM) C2

Pin

Wire Color

Circuit No.

Function

1

PU

2121

IC 1 Control

2

TN

1664

HO2S Low Signal

3

PU/WH

1665

HO2S High Signal

4

PU/WH

1668

HO2S High Signal

5

TN/WH

1669

HO2S Low Signal

6

L-BU

1876

Knock Sensor 2 Signal

7

GY

2303

Knock Sensor 2 Signal

8

D-BU

496

Knock Sensor 1 Signal

9

GY

1716

Knock Sensor 1 Signal

10

--

--

Not Used

11

YE

581

TAC Motor Control 1

12

BN

582

TAC Motor Control 2

13

PK/BK

5290

Ignition 1 Voltage

14-15

--

--

Not Used

16

PK/BK

1746

Fuel Injector 3 Control

17

PU/WH

2128

IC 8 Control

18

D-GN/WH

2124

IC 4 Control

19

BN/WH

2130

Low Reference

20-22

--

--

Not Used

23

PK/BK

632

Low Reference

24

BK

2755

Low Reference

25-26

--

--

Not Used

27

YE/BK

1868

Low Reference

28

--

--

Not Used

29

BK/WH

1704

Low Reference

30-31

--

--

Not Used

32

L-GN/BK

1745

Fuel Injector 2 Control

33

RD

2127

IC 7 Control

34

D-GN

2125

IC 5 Control

35

BN

2129

Low Reference

36-38

--

--

Not Used

39

RD

631

5-Volt Reference 1

40

GY

2705

5-Volt Reference 1

41

--

--

Not Used

42

BK

2760

Low Reference

43

L-GN

1867

5-Volt Reference 2

44

L-BU/BK

1688

5-Volt Reference 2

45-47

--

--

Not Used

48

D-BU/WH

878

Fuel Injector 8 Control

49

BK/WH

845

Fuel Injector 5 Control

50-51

--

--

Not Used

52

YE/BK

846

Fuel Injector 6 Control

53

RD/WH

2122

IC 2 Control

54

L-BU/WH

2126

IC 6 Control

55

L-BU

2123

IC 3 Control

56-58

--

--

Not Used

59

BN/WH

633

CMP Sensor Signal

60

TN/WH

331

Oil Pressure Switch Signal

61

--

--

Not Used

62

TN

472

IAT Sensor Signal

63

D-BU/WH

1869

CKP Sensor Signal

64

D-GN

485

TP Sensor 1 Signal

65

--

--

Not Used

66

PU

486

TP Sensor 2 Signal

67

YE

492

MAF Sensor Signal

68

BK/WH

3113

HO2S Heater Low Control Sensor

69

BN

2391

HO2S Heater Low Control - Sensor 2

70

L-BU/BK

844

Fuel Injector 4 Control

71

RD/BK

877

Fuel Injector 7 Control

72

BK

1744

Fuel Injector 1 Control

73

BK/WH

451

Ground

Engine Control Module (ECM) C3


Object Number: 1673472  Size: CH

Connector Part Information

  • OEM: 13579472
  • Service: 88988372
  • Description: 73-Way F MX123 34566 Series (GY)

Terminal Part Information

  • Pins: 7, 10-12, 17, 18, 21, 23, 28, 29, 33, 35, 37, 39, 44, 46, 48, 49, 53, 55, 57, 59, 66, 68, 69,
  • Terminal/Tray: 15359541/4
  • Core/Insulation Crimp: M/M
  • Release Tool/Test Probe: 15381651-2/J-35616-64B (L-BU)

Engine Control Module (ECM) C3

Pin

Wire Color

Circuit No.

Function

1-6

--

--

Not Used

7

RD

225

Generator Turn On Signal

8-9

--

--

Not Used

10

TN

5496

Cylinder 6 Shutoff Solenoid Control

11

D-BU

5491

Cylinder 1 Shutoff Solenoid Control

12

TN/BK

464

Delivered Torque Signal

13-16

--

--

Not Used

17

OG/BK

463

Requested Torque Signal

18

BN

1174

Oil Level Switch Signal

19-20

--

--

Not Used

21

BK

2751

Low Reference

22

--

--

Not Used

23

OG/BK

469

Low Reference

24-27

--

--

Not Used

28

RD/BK

645

Low Reference

29

GY

23

Generator Field Duty Cycle Signal

30-32

--

--

Not Used

33

TN

2501

High-Speed GMLAN Serial Data Bus (-)

34

--

--

Not Used

35

BK

2761

Low Reference

36

--

--

Not Used

37

GY

2700

5-Volt Reference 1

38

--

--

Not Used

39

GY

2704

5-Volt Reference 1

40-43

--

--

Not Used

44

GY

605

5-Volt Reference 2

45

--

--

Not Used

46

OG/BK

1786

Park/Neutral Signal

47

--

--

Not Used

48

D-GN/WH

428

EVAP Canister Purge Solenoid Control

49

D-GN

335

Low Speed Cooling Fan Relay Control

50-52

--

--

Not Used

53

TN/WH

2500

High-Speed GMLAN Serial Data Bus (+)

54

--

--

Not Used

55

YE

410

ECT Sensor Signal

56

--

--

Not Used

57

RD/BK

380

A/C Refrigerant Pressure Sensor Signal

58

--

--

Not Used

59

L-GN

432

MAP Sensor Signal

60-65

--

--

Not Used

66

RD

381

Vehicle Speed Signal

67

--

--

Not Used

68

WH

5497

Cylinder 7 Shutoff Solenoid Control

69

OG

5494

Cylinder 4 Shutoff Solenoid Control

70-73

--

--

Not Used