For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P0201: Injector 1 Control Circuit
DTC P0202: Injector 2 Control Circuit
DTC P0203: Injector 3 Control Circuit
DTC P0204: Injector 4 Control Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Ignition 1 Voltage - Fuse to Splice | ¹ | ² | -- | --
Ignition 1 Voltage - Splice to Injector | ¹ | P0201, P0202, P0203, or P0204 | -- | --
Fuel Injector 1 Control | P0201, P0300 | P0201, P0300 | P0201 | --
Fuel Injector 2 Control | P0202, P0300 | P0202, P0300 | P0202 | --
Fuel Injector 3 Control | P0203, P0300 | P0203, P0300 | P0203 | --
Fuel Injector 4 Control | P0204, P0300 | P0204, P0300 | P0204 | --
¹Open fuse, cranks no start ²Cranks no start

### Circuit/System Description

The control module enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The control module controls each fuel injector by grounding the control circuit via a solid state device called a driver. The control module monitors the status of each driver. If the control module detects an incorrect voltage for the commanded state of the driver, a fuel injector control circuit DTC sets.

### Conditions for Running the DTC

• | The engine is running.

• | The ignition voltage is between 9-18 volts for more than 1 second.

• | These DTCs run continuously when the above conditions are met.

### Conditions for Setting the DTC

• | The control module detects an incorrect voltage on the fuel injector control circuit.

• | The above condition is met for more than 6 seconds.

### Action Taken When the DTC Sets

• | DTCs P0201, P0202, P0203, P0204 are Type B DTCs.

• | The driver information center (DIC) displays the Service Traction, Service ESC, and ESC OFF messages.

### Conditions for Clearing the DTC

DTCs P0201, P0202, P0203, P0204 are Type B DTCs.

### Diagnostic Aids

Performing the Fuel Injector Diagnosis may help isolate an intermittent condition. Refer to Fuel Injector Diagnosis.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

#### Special Tools

J 44603 Injector Test Lamp

### Circuit/System Verification

1. Engine idling, observe the following control circuit status parameters for each fuel injector:

• | INJ Ckt Short Gnd Test Status

• | INJ Ckt Open Test Status

• | INJ Ckt Short Volts Test Status

• | Each parameter should display OK or Not Run.

2. Engine running, observe the DTC information with a scan tool. DTCs P0201, P0202, P0203, or P0204 should not set.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate fuel injector.
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal A and ground.

⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test or replace the fuel injector.

3. Ignition OFF, connect a J 44603 Test Lamp between the control circuit terminal B and the ignition circuit terminal A of the appropriate fuel injector.
4. Engine cranking, the test lamp should flash.

⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the engine control module (ECM).

⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

5. If all circuits test normal, test or replace the fuel injector.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Fuel Injector Replacement

• | Control Module References for replacement, setup, and programming