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
^ 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. Intermittent Conditions

TEST DESCRIPTION

Steps 1-12:

The numbers below refer to the step numbers on the diagnostic table.
4. This step tests for a short to ground on the fuel injector B+ supply circuit.
5. This step tests for a short to a PCM ground on the fuel injector B+ supply circuit.
6. This step tests for an open ignition feed circuit between the fuel pump relay and the fuel injectors.
7. This step tests for high resistance between the fuel pump relay and the fuel injectors.