Fuel Pump Electrical Circuit Diagnosis

FUEL PUMP ELECTRICAL CIRCUIT DIAGNOSIS

CIRCUIT DESCRIPTION
The control module enables the fuel pump relay when the ignition switch is turned ON. The control module will disable the fuel pump relay within 2 seconds unless the control module detects ignition reference pulses. The control module continues to enable the fuel pump relay as long as ignition reference pulses are detected. The control module disables the fuel pump relay within two seconds if ignition reference pulses cease to be detected and the ignition remains ON.

DIAGNOSTIC AIDS




The following conditions may have caused the fuel pump fuse to open:
- The fuse was faulty.
- There is an intermittent short in the supply voltage circuit of the fuel pump.
- The fuel pump has an internal intermittent condition.

For an intermittent condition, refer to Intermittent Conditions. Diagnostic Strategies

TEST

Steps 1-5:

Steps 6-14:

Steps 15-22:

Steps 23-30: