XB156 - Check Fuel Pump Circuits For Shorts or Opens

- Key "OFF".

- Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- Connect a test lamp between test pin 8 and test pin 37 at the breakout box.

- Key "ON", engine "OFF".

- Observe test lamp for an indication of a fault while performing the following: (The light will go out if an open circuit is detected. The light will also go out, and the fuel pump will run, if a short to power or High Speed Fuel Pump (HFP) circuit short to ground is detected.)

- Shake, wiggle, bend the following circuits: Fuel Pump Monitor (FPM)/, power-to-pump (Variable Control Relay Module (VCRM) to fuel pump, including circuit to HFP relay), fuel pump ground and HFP circuit between the HFP relay and VCRM.

- Lightly tap on the Inertia Fuel Shutoff switch, HFP relay and VCRM (to simulate road shock).

- Is a fault indicated?

Yes -- Isolate fault and service as necessary. Remove breakout box. Reconnect all components. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Go to XB158 (to check left Heated Oxygen Sensor (HO2S) for intermittent short to power). XB158 - Check Left O2S Circuit For Intermittent Short to Power