Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

1999 Chevrolet Prizm Base, StandardFACTORY OEM SERVICE PROCEDURE

Powertrain Control Module (Pcm) Connector Terminal Identification

Fig 1: Identifying Powertrain Control Module (PCM) Harness Connector Terminals

Courtesy of GENERAL MOTORS CORP.

POWERTRAIN CONTROL MODULE (PCM) CONNECTOR TERMINAL IDENTIFICATION (1.0L)

Connector/Terminal No. ⁽¹⁾

Wire Color

Function

C1/1

BLK/GRN

PCM Ground

C1/2

WHT/BLU

Ignition Positive Voltage

C1/3

RED/WHT

EVAP Canister Vent Solenoid Control

C1/4

PNK

HO2S 2 Heater Control

C1/5

RED/BLK

EGR By-Pass Valve Control

C1/6

GRN

EGR Solenoid Vacuum Valve Control

C1/7

RED/GRN

EVAP Canister Purge Valve Control

C1/8 & 9

.....

Not Used

C1/10

ORG

Ignition Trigger Signal

C1/11

GRY/YEL

Idle Speed Control (ISC) Motor Control

C1/12

YEL/BLK

Fuel Injector Control

C1/13

BLK/BLU

PCM Ground

C1/14

WHT

Memory Power Input

C1/15

WHT/BLU

Ignition Positive Voltage

C1/16

GRY/BLK

Idle Speed Control (ISC) Motor Relay Control

C1/17

PPL/YEL

MIL Control

C1/18

PPL/RED

Upshift Indicator Light Control

C1/19

RED/BLU

EVAP Tank Pressure Control Solenoid Control Vacuum Valve Control

C1/20

BLU

Engine Cooling Fan Relay Control

C1/21

PNK/WHT

Fuel Pump Relay Control

C1/22

BLU/BLK

Main Relay Control

C1/23

.....

Not Used

C1/24

GRY/RED

Idle Speed Control (ISC) Motor Control

C1/25

YEL/RED

Early Fuel Evaporation (EFE) Heater Relay Control

C1/26

BLK/RED

PCM Ground

C2/1

LT GRN

Reference Voltage

C2/2

ORG

Ignition Reference High (CMP Sensor)

C2/3

WHT/BLK

Ignition Reference High (CKP Sensor)

C2/4

GRY/GRN

Closed Throttle Position (CTP) Switch Signal

C2/5

LT GRN/RED

MAP Sensor Input

C2/6

LT GRN/WHT

TP Sensor Input

C2/7

GRY/WHT

ECT Sensor Input

C2/8

PNK/BLK

HO2S 1 Heater Control

C2/9

LT GRN/BLK

Sensor Ground

C2/10

WHT

Ignition Reference Low (CMP Sensor)

C2/11

WHT/RED

Ignition Reference Low (CKP Sensor)

C2/12

WHT/BLK

Early Fuel Evaporation (EFE) ON Signal

C2/13

RED

HO2S 1 Signal

C2/14

GRY

IAT Sensor Input

C2/15

.....

Not Used

C2/16

BLK/YEL

Clutch Pedal Position (CCP) Switch Input

C3/1-5

.....

Not Used

C3/6

BLU/YEL

Diagnostic Request Signal

C3/7

PPL/GRN

Test Switch Signal

C3/8

YEL

HO2S 2 Signal

C3/9

.....

Not Used

C3/10

YEL/RED

Fuel Level Sensor Input

C3/11

YEL/GRN

VSS Input

C3/12

PPL/WHT

Serial Data Output

C3/13-16

.....

Not Used

C3/17

LT GRN/RED

A/C Cut-Out Control

C3/18

BRN/YEL

Electrical Load Idle-Up Signal

C3/19

BLU/RED

A/C Idle-Up Signal

C3/20

BLK/WHT

Ignition Positive Signal

C3/21

LT GRN/YEL

Fuel Tank Pressure Sensor Input

C3/22

.....

Not Used

⁽¹⁾	See Fig 1.

POWERTRAIN CONTROL MODULE (PCM) CONNECTOR TERMINAL IDENTIFICATION (1.3L)

Connector/Terminal No. ⁽¹⁾

Wire Color

Function

C1/1

BLK/GRN

PCM Ground

C1/2

WHT/BLU

Ignition Positive Voltage

C1/3

PNK/BLU

EVAP Canister Vent Solenoid Control

C1/4

PNK

HO2S 2 Heater Control

C1/5

ORG/GRN

Shift Solenoid B (A/T)

C1/6

ORG

Shift Solenoid A (A/T)

C1/7

RED/GRN

EVAP Canister Purge Valve Control

C1/8 & 9

.....

Not Used

C1/10

GRY/RED

Ignition Trigger Signal 1-4 Coil

C1/11

BRN/BLK

Fuel Injector No. 3 Control

C1/12

BRN/WHT

Fuel Injector No. 1 Control

C1/13

BLK/BLU

PCM Ground

C1/14

WHT

Memory Power Input

C1/15

WHT/BLU

Ignition Positive Voltage

C1/16

LT GRN/RED

EVAP Tank Pressure Control Solenoid Vacuum Valve Control

C1/17

PPL/YEL

MIL Control

C1/18

PNK/WHT

Fuel Pump Relay Control

C1/19

BLU/BLK

Main Relay Control

C1/20

BLU

Engine Cooling Fan Relay Control

C1/21 & 22

.....

Not Used

C1/23

GRY/BLU

Ignition Trigger Signal 2-3 Coil

C1/24

BRN/YEL

Fuel Injector No. 4 Control

C1/25

BRN/RED

Fuel Injector No. 2 Control

C1/26

BLK/RED

PCM Ground

C2/1

LT GRN

Reference Voltage

C2/2

ORG

Ignition Reference High (CMP Sensor)

C2/3

WHT/BLK

Ignition Reference High (CKP Sensor)

C2/4

PPL ⁽²⁾

VSS High

C2/5

ORG/GRN

MAP Sensor Input

C2/6

LT GRN/WHT

TP Sensor Input

C2/7

PNK/BLK

HO2S 1 Heater Control

C2/8

.....

Not Used

C2/9

LT GRN/BLK

Sensor Ground

C2/10

GRY/WHT

ECT Sensor Input

C2/11

WHT/RED

Ignition Reference Low (CKP Sensor)

C2/12

GRY/YEL

VSS Low (A/T)

C2/13

RED

HO2S 1 Signal

C2/14

GRY

IAT Sensor Input

C2/15

BLU/WHT

Power Steering Pressure Switch Input

C2/16

BLK/YEL

Transmission Range (TR) Switch Input (A/T); Closed Pedal Position (CPP) Switch Input (M/T)

C3/1

.....

Not Used

C3/2

RED/YEL

Idle Air Control (IAC) Valve

C3/3

GRN

2 Position Signal (A/T)

C3/4

ORG/YEL

N Position Signal (A/T)

C3/5

ORG/BLK

P Position Signal (A/T)

C3/6

BRN

Tachometer (If Equipped)

C3/7

PPL/GRN

Test Switch Signal

C3/8

BLU/YEL

Diagnostic Request Signal

C3/9

BLK/BLU

Ground (With Tachometer)

C3/10

YEL

HO2S 2 Signal

C3/11

YEL/RED

Fuel Level Sensor Input

C3/12

PPL/WHT

Serial Data Output

C3/13

PPL/RED

Duty Output Terminal

C3/14

GRN/BLU

L Position Signal (A/T)

C3/15

GRN/RED

D Position Signal (A/T)

C3/16

RED

R Position Signal (A/T)

C3/17

GRY

A/C Cut-Out Control

C3/18

BRN/WHT

Electrical Load Idle-Up Signal

C3/19

BLU/RED

A/C Idle-Up Signal

C3/20

BLK/WHT

Ignition Positive Voltage

C3/21

LT GRN/YEL

Fuel Tank Pressure Sensor Input

C3/22

LT GRN/BLK

Sensor Ground

⁽¹⁾	See Fig 1.

⁽²⁾	Yellow/Green wire on M/T.

POWERTRAIN CONTROL MODULE (PCM) CONNECTOR TERMINAL IDENTIFICATION (1.8L)

Connector/Terminal No. ⁽¹⁾

Wire Color

Function

C1/1

BLK/WHT

Ignition Positive Voltage (4-spd A/T)

C1/2

.....

Not Used

C1/3

.....

Not Used

C1/4

BLK

Crankshaft Position Signal

C1/5

BLK

Camshaft Position Signal

C1/6

BLU/RED

Power Steering Pressure Signal

C1/7

RED

EVAP Pressure Switching Solenoid Control

C1/8

BLU/BLK

EVAP Canister Purge Solenoid Valve Control

C1/9

.....

Not Used

C1/10

BLK/BLU

IAC Open Control

C1/11

BLK/RED

Fuel Injector No. 2 Control

C1/12

YEL

Fuel Injector No. 1 Control

C1/13

BRN

Ground

C1/14

BRN

Ground

C1/15

.....

Not Used

C1/16

BLU/YEL

Ignition Fail-Safe Input

C1/17

WHT

CMP & CKP Sensor Ground

C1/18

.....

Not Used

C1/19

RED/BLU

Ignition Trigger Signal 2

C1/20

YEL/GRN

Ignition Trigger Signal 1

C1/21

BLU/YEL

TCC Solenoid Control (4-spd A/T)

C1/22

BRN/YEL

Shift Solenoid No. 2 Control (4-spd A/T)

C1/23

PPL

Shift Solenoid No. 1 Control (4-spd A/T)

C1/24

BLK

Fuel Injector No. 4 Control

C1/25

WHT

Fuel Injector No. 3 Control

C1/26

BRN

Ground

C2/1

YEL

Reference Voltage

C2/2

LT GRN/RED

MAP Input

C2/3

YEL/BLK

IAT Input

C2/4

WHT

ECT Input

C2/5

RED

HO2S 2 Signal Input

C2/6

WHT

HO2S 1 Signal Input

C2/7

BLU

Fuel Tank Pressure Sensor Input

C2/8

PNK

HO2S 1 Heater Control

C2/9

BRN

Sensor Ground

C2/10

.....

Not Used

C2/11

LT GRN

TP Input

C2/12

RED/WHT

O/D Cut Signal (4-spd A/T)

C2/13

BLK

Knock Input

C2/14

PNK

HO2S 2 Heater Control

C2/15

BLU/WHT

Diagnostic Request

C2/16

BRN

Ground

C3/1

RED/WHT

Battery Positive Voltage

C3/2

BLK

Idle Up Signal (Defoggers)

C3/3

BLU/WHT

Idle Signal Control (Cruise Control)

C3/4

GRN/WHT

Brake Signal

C3/5

RED/YEL

MIL Control

C3/6 & 7

.....

Not Used

C3/8

BLK

Engine Speed Output

C3/9

PPL/WHT

VSS Input

C3/10

YEL/RED

A/C ON Signal

C3/11

BLK/WHT

Crank Signal

C3/12

BLK

Ignition Positive Voltage

C3/13

GRN

Idle Up Signal (Taillights)

C3/14

GRN/RED

Circuit Opening Relay

C3/15

.....

Not Used

C3/16

WHT

Serial Data Line

C3/17

RED/BLK

R Position Signal (4-spd A/T)

C3/18

LT GRN/RED

2 Position Signal (4-spd A/T)

C3/19

LT GRN/BLK

L Position Signal (4-spd A/T)

C3/20

.....

Not Used

C3/21

RED/BLU

A/C Cut-Out Control

C3/22

LT GRN

O/D On/Off Signal (4-spd A/T)

⁽¹⁾	See Fig 1.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.

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