Fuel Injector Circuit Diagnosis

FUEL INJECTOR CIRCUIT DIAGNOSIS

CIRCUIT DESCRIPTION
The powertrain control module (PCM) enables the appropriate fuel injector on the intake stroke for each cylinder. A voltage is supplied directly to the fuel injectors. The PCM controls each fuel injector by grounding the control circuit via a solid state device called a driver.

DIAGNOSTIC AIDS
- Monitoring the fuel injector circuit status with a scan tool, while moving the fuel injector harness, may help isolate an intermittent condition.
- Performing the Fuel Injector Coil Test may help isolate an intermittent condition. Refer to Fuel Injector Coil Test. Component Tests and General Diagnostics
- For an intermittent condition, refer to Intermittent Conditions. Diagnostic Strategies

TEST DESCRIPTION

Steps 1-6:

Steps 7-14:

The numbers below refer to the step numbers on the diagnostic table.
4. This step tests for a short to ground on the ignition 1 voltage supply circuit of the fuel injector.
5. This step tests for a short to a PCM ground on the ignition 1 voltage supply circuit of the fuel injector.
6. This step tests for an open between the multi-way connector and the fuel injectors.
7. This step tests for an open or high resistance between the multi-way connector and the fuel injectors.