J95 - Check EEC-IV Harness

A Continuous Memory Diagnostic Trouble Code (DTC) 556 indicates that a fuel pump primary circuit failure has occurred during vehicle operation.

Possible causes are:

- Open in VPWR circuit between the Electronic Engine Controls (EEC) power relay and the fuel pump relay.

- Open coil in fuel pump relay.

- Open in fuel pump circuit (Pin 22).

- Start engine.

- Check for engine stall/stumble while performing the following (also, if possible, listen for fuel pump turning off):

- Shake, wiggle, bend the VPWR circuit between the EEC power relay and the fuel pump relay. For vehicles with the Inertia Fuel Shutoff (IFS) switch in the VPWR circuit (refer to schematic), lightly tap the Inertia Fuel Shutoff (IFS) switch to simulate road shock.

- Shake, wiggle, bend the Powertrain Control Module (PCM) vehicle harness fuel pump circuit (Pin 22) between the PCM and the fuel pump relay.

- Lightly tap the fuel pump relay to simulate road shock.

- Key "OFF".

- Inspect the PCM connector and the fuel pump relay connectors for corrosion, damaged pins, etc.

- Is fault indicated/found?

Yes -- Isolate fault and service as necessary. Clear continuous memory. Clearing Diagnostic Trouble Codes

Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- For dual Heated Oxygen Sensor (HO2S) applications with a DTC 543 only: Go to J96. J96 - Check Left/Front HO2S Circuit For Short to Power

ALL others: For further diagnosis using an EEC-IV monitor box or Scan Tool, go to Normal Scan Data Values. If an EEC-IV monitor box or Scan Tool is not available, go to J99. J99 - Road Test