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: 784851  Size: CH

Connector Part Information

  • OEM: 13510837 (Early Production) / 13574282 (Late Production)
  • Service: 88988373
  • Description: 56-Way F Receptacle 0.64 Series Sealed (BU) / 33-Way F Sealed (BU)

Terminal Part Information

  • Pins: 1-2, 4, 9, 12-13, 16, 18, 20-22, 24-25, 30-37, 39-40, 44, 46-49, 53, 55-56
  • Terminal/Tray: 33467-0003/23
  • Core/Insulation Crimp: H/H
  • Release Tool/Test Probe: J-38125-213/J-35616-64B (L-BU)
  • Pins: 7, 19
  • Terminal/Tray: 33467-0005/23
  • Core/Insulation Crimp: J/J
  • Release Tool/Test Probe: J-38125-213/J-35616-64B (L-BU)

Engine Control Module (ECM) C1

Pin

Wire Color

Circuit No.

Function

1

PU

806

Crank Voltage

2

PU

420

TCC Brake Switch/Cruise Control Release Signal

3

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

4

GY/BK

1694

4WD Low Signal (NP8)

5-6

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

7

L-BU

1320

CHMSL Supply Voltage (K34)

8

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

9

BK

2759

Low Reference

10-11

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

12

BN/WH

419

MIL Control

13

D-GN/WH

465

Fuel Pump Relay Control

14-15

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

16

D-GN

1049

Class 2 Serial Data

17

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

18

PK

1020

Ignition 0 Voltage

19

PK

439

Ignition 1 Voltage

20

OG

240

Battery Positive Voltage

21

GY/BK

87

Cruise Control Resume/Accel Switch Signal (K34)

22

D-BU

84

Cruise Control Set/Coast Switch Signal (K34)

23

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

24

YE/BK

1827

Vehicle Speed Signal

25

WH

121

Engine Speed Signal

26-29

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

30

GY

397

Cruise Control On Switch Signal (K34)

31

BK

452

Low Reference

32

GY

416

5-Volt Reference

33

WH/BK

1164

5-Volt Reference

34

GY

2709

5-Volt Reference

35

TN

1274

5-Volt Reference

36

BN

1271

Low Reference

37

PU

1272

Low Reference

38

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

39

D-GN/WH

817

Vehicle Speed Signal

40

YE

5991

Powertrain Relay Coil Control

41-43

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

44

PU

1589

Fuel Level Sensor Signal

45

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

46

D-BU

1809

Brake Booster Vacuum Sensor

47

D-BU

1161

APP Sensor 1 Signal

48

D-GN

890

Fuel Tank Pressure Sensor

49

L-BU

1162

App Sensor 2 Signal

50-52

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

53

D-GN/WH

459

A/C Compressor Clutch Relay Control

54

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

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: 15499466 (Early Production) / 13574286 (Late Production)
  • Service: 88988931
  • Description: 73-Way F Receptacle 0.64 2.8 Series Sealed (BK) (Early Production) / 48-Way F Recptacle 0.64 Series Sealed (BK) (Late Production)

Terminal Part Information-

  • Pins: 1-5, 11-13, 16-19, 32-35, 42, 48-49, 52-55, 62, 67-72
  • Terminal/Tray: 33467-0005/23
  • Core/Insulation Crimp: J/J
  • Release Tool/Test Probe: J-38125-213/J-35616-64B (L-BU)
  • Pins: 6-9, 23-24, 27, 29, 39-40, 43-44, 59-60, 63-64, 66
  • Terminal/Tray: 33467-0003/23
  • Core/Insulation Crimp: H/H
  • Release Tool/Test Probe: J-38125-213/J-35616-64B (L-BU)
  • Pins: 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 - Bank 1 Sensor 1

3

PU/WH

1665

HO2S High Signal - Bank 1 Sensor 1

4

PU/WH

1668

HO2S High Signal - Bank 1 Sensor 2

5

TN/WH

1669

HO2S Low Signal - Bank 1 Sensor 2

6

L-BU

1876

KS 2 Signal

7

GY

2303

KS 2 Signal

8

D-BU

496

KS 1 Signal

9

GY

1716

KS 1 Signal

10

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

11

YE

581

TAC Motor Control 1

12

BN

582

TAC Motor Control 2

13

PK

839

Ignition 1 Voltage

14-15

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

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 (Early Production)

--

--

Not Available (Late Production)

23

BN/WH

633

Low Reference (Early Production)

PK/BK

632

Low Reference (Late Production)

24

BK

2755

Low Reference

25-26

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

27

D-BU/WH

1869

Low Reference (Early Production)

YE/BK

1868

Low Reference (Late Production)

28

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

29

BK/WH

1704

Low Reference

30-31

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

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 (Early Production)

--

--

Not Available (Late Production)

39

RD

631

5-Volt Reference

40

GY

2705

5-Volt Reference

41

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

42

BK

2760

Low Reference

43

L-GN

1867

5-Volt Reference

44

L-BU/BK

1688

5-Volt Reference

45-47

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

48

D-BU/WH

878

Fuel Injector 8 Control

49

BK/WH

845

Fuel Injector 5 Control

50-51

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

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 (Early Production)

--

--

Not Available (Late Production)

59

PK/BK

632

CMP Sensor Signal (Early Production)

BN/WH

633

CMP Sensor Signal (Late Production)

60

TN/WH

332

Oil Pressure Sensor Signal

61

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

62

TN

472

IAT Sensor Signal

63

YE/BK

1868

CKP Sensor Signal (Early Production)

D-BU/WH

1869

CKP Sensor Signal (Late Production)

64

D-GN

485

TP Sensor 1 Signal

65

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

66

PU

486

TP Sensor 2 Signal

67

YE

492

MAF Sensor Signal

68

BK/WH

3113

HO2S Heater Low Control - Bank 1 Sensor 1

69

BN

2391

HO2S Heater Low Control - Bank 1 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

450

Ground

Engine Control Module (ECM) C3


Object Number: 1673472  Size: CH

Connector Part Information

  • OEM: 15497996 (Early Production) / 13574284 (Late Production)
  • Service: 88988372
  • Description: 73-Way F Receptacle 0.64 2.8 Series Sealed (GY) / 32-Way F Sealed (GY)

Terminal Part Information

  • Pins: 3-6, 10-11, 15, 48, 50, 68-69
  • Terminal/Tray: 33467-0005/23
  • Core/Insulation Crimp: J/J
  • Release Tool/Test Probe: J-38125-213/J-35616-64B (L-BU)
  • Pins: 7, 12, 17, 21, 23, 28-29, 33, 35, 37, 39, 44, 47, 49, 53, 55, 57, 59, 64, 66
  • Terminal/Tray: 33467-0003/23
  • Core/Insulation Crimp: H/H
  • Release Tool/Test Probe: J-38125-213/J-35616-64B (L-BU)

Engine Control Module (ECM) C3

Pin

Wire Color

Circuit No.

Function

1-2

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

3

TN

1667

HO2S Low Signal - Bank 2 Sensor 1

4

PU

1666

HO2S High Signal - Bank 2 Sensor 1

5

PU

1670

HO2S High Signal - Bank 2 Sensor 2

6

TN

1671

HO2S Low Signal - Bank 2 Sensor 2

7

PU

5428

Generator Regulator Control

8-9

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

10

GY

5493

Cylinder 6 Shutoff Solenoid Control 3

11

D-BU

5491

Cylinder 1 Shutoff Solenoid Control 1

12

TN/BK

464

Delivered Torque Signal

13-14

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

15

L-GN

3212

HO2S Heater Low Control - Bank 2 Sensor 1

16

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

17

OG/BK

463

Requested Torque Signal

18-20

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

21

BK

2751

Low Reference

22

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

23

OG/BK

469

Low Reference

24-27

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

28

GY

2365

Low Reference

29

GY

23

Generator Field Duty Cycle Signal

30-32

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

33

TN

2501

High Speed GMLAN Serial Data Bus -

34

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

35

BK

2761

Low Reference

36

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

37

GY

2700

5-Volt Reference

38

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

39

GY

2704

5-Volt Reference

40-43

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

44

GY

597

5-Volt Reference

45-46

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

47

OG/BK

1786

PNP Switch Signal

48

D-GN/WH

428

EVAP Canister Purge Solenoid Control

49

WH/BK

2366

Cooling Fan Clutch Control

50

RD/WH

3223

HO2S Heater Low Control - Bank 2 Sensor 2

51-52

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

53

TN/WH

2500

High Speed GMLAN Serial Data Bus +

54

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

55

YE

410

ECT Sensor Signal

56

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

57

RD/BK

380

A/C Refrigerant Pressure Sensor

58

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

59

L-GN

432

MAP Sensor Signal

60-63

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

64

D-BU

2364

Cooling Fan Speed Signal

65

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

66

YE

400

Signal High - Front

67

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

68

L-GN

5492

Cylinder 7 Shutoff Solenoid Control 4

69

OG

5494

Cylinder 4 Shutoff Solenoid Control 2

70-72

--

--

Not Used (Early Production)

--

--

Not Available (Late Production)

73

--

--

Not Used