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

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Fuel Injector 1-3-5 Ignition Voltage

P0201¹, P0203¹, P0205¹, P0300¹

P0201, P0203, P0205

--

--

Fuel Injector 2-4-6 Ignition Voltage

P0202¹, P0204¹, P0206¹, P0300¹

P0202, P0204, P0206, P0300

--

--

Fuel Injector 1 Control

P0201, P0300

P0201, P0300

P0201, P0300

--

Fuel Injector 2 Control

P0202, P0300

P0202, P0300

P0202, P0300

--

Fuel Injector 3 Control

P0203, P0300

P0203, P0300

P0203, P0300

--

Fuel Injector 4 Control

P0204, P0300

P0204, P0300

P0204, P0300

--

Fuel Injector 5 Control

P0205, P0300

P0205, P0300

P0205, P0300

--

Fuel Injector 6 Control

P0206, P0300

P0206, P0300

P0206, P0300

--

¹Open fuse

Circuit/System Description

The control module enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to each bank of fuel injectors through a separate fuse. 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 more than 11 volts for 5 seconds.
    • DTC P0201-P0206 runs 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 1 second.

Action Taken When the DTC Sets

DTCs P0201-P0206 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0201-P0206 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

Circuit/System Verification

Key ON, observe the DTC information with a scan tool. DTC P0201, P0202, P0203, P0204, P0205, or P0206 should not be set.

Circuit/System Testing

  1. Ignition OFF, disconnect the X101 fuel injector multi-way connector.
  2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminals A and E engine control module (ECM) harness side and ground.
  3. If the test lamp does not illuminate, test the ignition circuits for a short to ground, or an open/high resistance. If the circuits test normal and the ignition circuit fuse is open, test or replace the fuel injector.
  4. Ignition OFF, connect a test lamp between the ignition circuit terminal A and the control circuit ECM harness side, of the appropriate injector listed below:
  5. • Injector 1 terminal B
    • Injector 2 terminal F
    • Injector 3 terminal C
    • Injector 4 terminal G
    • Injector 5 terminal D
    • Injector 6 terminal H
  6. Engine cranking, the test lamp should flash for each injector.
  7. If the test lamp is always ON, test the appropriate control circuit for a short to ground. If the circuit tests normal, replace the ECM.
    If the test lamp is always OFF, test the appropriate control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  8. Ignition OFF, measure for 10-15 ohms on the engine harness side of X101 between the ignition circuit terminal A or E and the control circuit of the appropriate injector listed below:
  9. • Injector 1 terminal B
    • Injector 2 terminal F
    • Injector 3 terminal C
    • Injector 4 terminal G
    • Injector 5 terminal D
    • Injector 6 terminal H
         ⇒If the resistance is not within the specified range, test for a short to ground or an open/high resistance between X101 and the appropriate fuel injector harness connector. If the circuits test normal, test or replace the affected fuel injector.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Fuel Injector and Fuel Rail Replacement
    •  Control Module References for ECM replacement, setup, and programming