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
DTC P0205: Injector 5 Control Circuit
DTC P0206: Injector 6 Control Circuit
DTC P0261: Injector 1 Control Circuit Low Voltage
DTC P0262: Injector 1 Control Circuit High Voltage
DTC P0264: Injector 2 Control Circuit Low Voltage
DTC P0265: Injector 2 Control Circuit High Voltage
DTC P0267: Injector 3 Control Circuit Low Voltage
DTC P0268: Injector 3 Control Circuit High Voltage
DTC P0270: Injector 4 Control Circuit Low Voltage
DTC P0271: Injector 4 Control Circuit High Voltage
DTC P0273: Injector 5 Control Circuit Low Voltage
DTC P0274: Injector 5 Control Circuit High Voltage
DTC P0276: Injector 6 Control Circuit Low Voltage
DTC P0277: Injector 6 Control Circuit High Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Ignition 1 Voltage | P0201, P0202, P0203, P0204, P0205, P0206 | P0201, P0202, P0203, P0204, P0205, P0206 | -- | --
Injector 1 Control Circuit | P0261 | P0201 | P0262 | --
Injector 2 Control Circuit | P0264 | P0202 | P0265 | --
Injector 3 Control Circuit | P0267 | P0203 | P0268 | --
Injector 4 Control Circuit | P0270 | P0204 | P0271 | --
Injector 5 Control Circuit | P0273 | P0205 | P0274 | --
Injector 6 Control Circuit | P0276 | P0206 | P0277 | --

### Circuit/System Description

The control module enables the appropriate fuel injector on the intake stroke for each cylinder. Ignition voltage is supplied directly to the fuel injectors. The control module controls each fuel injector by grounding the control circuit with a solid state device called a driver. The control module monitors the status of each driver. Each driver has a feedback voltage circuit which the engine control module (ECM) monitors. The injector control circuits are pulled-up to voltage within the ECM . The ECM can determine if a control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

### Conditions for Running the DTC

• | The engine speed is more than 80 RPM.

• | The ignition voltage is between 10-18 volts.

• | The injector has been commanded ON and OFF at least once.

• | The DTCs run continuously once the above conditions are met.

### Conditions for Setting the DTC

#### P0201, P0202, P0203, P0204, P0205, or P0206

The ECM detects the injector control circuit is open for greater than 4 seconds or for a cumulative of 50 seconds.

#### P0261, P0264, P0267, P0270, P0273, or P0276

The ECM detects the injector control circuit is shorted to ground for greater than 4 seconds or for a cumulative of 50 seconds.

#### P0262, P0265, P0268, P0271, P0274, or P0277

The ECM detects the injector control circuit is shorted to voltage for greater than 4 seconds or for a cumulative of 50 seconds.

### Action Taken When the DTC Sets

DTCs P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, and P0277 are Type B DTCs.

### Conditions for Clearing the DTC

DTCs P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, and P0277 are Type B DTCs.

### Diagnostic Aids

• | Performing the fuel injector coil test may help isolate an intermittent condition. Refer to Fuel Injector Solenoid Coil Test .

• | If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the component with a scan tool. The circuit status parameter changes from OK or Indeterminate to Fault if there is a condition with the circuit or a connection.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls 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

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

1. Observe the Misfire Current Counters with a scan tool. The Misfire Current Counters should not be incrementing
2. Engine operating, observe the DTC information with a scan tool. DTCs P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, and P0277 should not set.

### Circuit/System Testing

Important: Disconnecting the multi-way harness connector causes DTCs P0201-P0206 fuel injector circuit open DTCs to set.

1. Ignition OFF, disconnect the fuel injector multi-way harness connector.
2. Ignition ON, connect a test lamp between the appropriate ignition voltage supply circuit on the ECM side of the multi-way connector and ground. Verify that the test lamp illuminates.

Important: The ignition voltage circuits supply voltage to other components. Make sure you test all circuits for a short to ground or test all components for being shorted that share the ignition circuit.

⇒ | If the test lamp does not illuminate and the fuse is open, repair the appropriate ignition circuit for a short to ground between the corresponding fuel injectors and the fuse. Replace the fuse.

⇒ | If the test lamp does not illuminate and the fuse is OK, repair the ignition voltage circuit for an open/high resistance between the multi-way connector and the fuse.

3. Connect a test lamp between the appropriate injector control circuit, ECM side of the multi-way harness connector, and B+. The test lamp should not illuminate.

⇒ | If the test lamp illuminates, test the control circuit for a short to ground. If circuit/connections test normal, replace the ECM.

4. Connect a test lamp between the appropriate injector control circuit, ECM side of the multi-way harness connector, and ground. The test lamp should not illuminate.

⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. If circuit/connections test normal, replace the ECM.

5. Ignition ON, test for 2.6-4.6 volts between the appropriate injector control circuit, ECM side of the multi-way connector, and ground.

⇒ | If the voltage is not within the specified range, test the control circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.

6. Remove the upper intake manifold. Refer to Upper Intake Manifold Replacement .
7. Disconnect the fuel injector connectors.
8. Test for continuity between the ignition voltage circuit(s) and the appropriate fuel injector control circuit, at the fuel injector side of the multi-way harness connector, the DMM should display OL.

⇒ | If less than OL repair the short between the ignition voltage circuit and the control circuit.

9. Test for less than 1 ohm of resistance in the appropriate ignition voltage circuit, between the injector connector(s) and the multi-way connector.

⇒ | If more than 1 ohm repair the open/high resistance in the ignition voltage circuit.

10. Test for less than 1 ohm of resistance in the suspected control circuit, between the injector connector and the multi-way connector.

⇒ | If more than 1 ohm repair the open/high resistance in the fuel injector control circuit.

11. Test for continuity between appropriate fuel injector control circuit and ground. The DMM should display OL.

⇒ | If less than OL repair the short to ground in the fuel injector control circuit.

12. Test for continuity between the suspected fuel injector control circuit and all the other control circuits of the fuel injectors. The DMM should display OL.

⇒ | If less than OL is measured between any of the control circuits, repair the wire to wire short between those circuits.

13. If all circuits/connections test normal, test or replace the appropriate fuel injector(s).

### Component Testing

1. Measure for 12-16 ohms of resistance between the terminals of the fuel injector.

⇒ | If the resistance is not within the specified range, replace the fuel injector.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Fuel Injector and Fuel Rail Replacement

• | Control Module References for engine control module replacement, setup, and programming