GM Service Manual Online
For 1990-2009 cars only

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 greater than 80 RPM.
    •  The ignition voltage is between 10-18 volts.
    • The fuel 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

The following table illustrates the ECM connector locations:

ECM Connector Location

X2

X1

Front of Vehicle

    • 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

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

Circuit/System Verification

  1. Observe the scan tool Misfire Current Counters. The Misfire Current Counters should not be incrementing
  2. Engine operating, observe the scan tool DTC information. DTCs P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, and P0277 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 are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing

  1. Ignition OFF, disconnect the fuel injector multi-way harness connector C109.
  2. Important: Testing for steps 2 through 4 is performed on the ECM side of the multi-way harness connector.

  3. Ignition ON, load test for B+ between the appropriate ignition voltage supply circuit and ground.
  4. If less than the specified range, repair the ignition voltage circuit for a short to ground, or an open/high resistance. Replace the fuse if necessary.
  5. Test for 2.6-4.6 volts between the appropriate fuel injector control circuit and ground
  6. If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  7. Probe the appropriate fuel injector control circuit with a test lamp connected to B+. Engine cranking, verify the test lamp flashes.
  8. If the test lamp remains OFF, test the control circuit for a high resistance. If the circuit/connections test normal, replace the ECM.

    Important: Testing for steps 5 and 6 is performed on the fuel injector side of the multi-way harness connector. It may be necessary to remove the upper intake manifold to isolate the condition. Refer to Upper Intake Manifold Replacement .

  9. Ignition OFF, test for OL ohms between the appropriate ignition voltage circuit and ground.
  10. If less than the specified range, repair the ignition voltage, or control circuit, for a short to ground. If the circuits/connections test normal, test or replace the appropriate fuel injector(s).
  11. Test for 12-16 ohms between the appropriate ignition voltage circuit and each fuel injector control circuit.
  12. If less than the specified range, test for a short between the control circuit and the ignition voltage circuit. If the circuits/connections test normal, test or replace the appropriate fuel injector(s).
    If greater than the specified range, test the ignition voltage, and fuel injector control circuit, for an open/high resistance. If the circuits/connections test normal, test or replace the appropriate fuel injector(s).

Component Testing

  1. Ignition OFF, disconnect the multi-way harness connector C109.
  2. Important: 

       • The ECT sensor must be between 10-32°C (5-90°F) in order for an accurate measurement.
       • Testing is performed on the fuel injector side of the multi-way harness connector.

  3. Test for 12-16 ohms between the ignition voltage circuit and the appropriate fuel injector control circuit.
  4. If 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