Fuel Pump Relay: Testing and Inspection

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Engine Controls Schematics: PCM Fuel Tank Inputs:

CIRCUIT DESCRIPTION
The PCM controls the fuel pump relay by supplying switched ignition voltage to the fuel pump relay coil. When the ignition switch is first turned On, the PCM energizes the fuel pump relay. The relay contacts close applying power to the fuel pump. The fuel pump relay will remain On as long as the engine is running or cranking and the PCM is receiving reference pulses. If no reference pulses are present, the PCM de-energizes the fuel pump relay within 2 seconds. With the engine stopped, the fuel pump can be turned On with a scan tool.

If the PCM detects a problem on the relay control circuit, DTC P0230 will set. Use this table if DTC P0230 is not set and a problem exists with the fuel pump.

DIAGNOSTIC AIDS

NOTE: Refer to Connector Test Adapter kit J 35616-A Notice in Service Precautions.

If the problem is intermittent, refer to Intermittent Conditions.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. Command both the ON and OFF states. Repeat the commands as necessary.
3. This step determines if the condition is located on the coil side or the switch side of the circuit.
4. This step verifies that the PCM is providing voltage to the fuel pump relay.
5. This step tests for an open in the ground circuit to the fuel pump relay.
6. This step determines if a voltage is constantly being applied to the fuel pump relay.
13. This step determines if the condition with the circuit is intermittent. If the fuse does not open, inspect the supply voltage circuit between the fuse and the fuel pump for an intermittent condition.