X70 - Code 556 or 557: Check Fuel Pump Relay Coil Resistance

DTC 556 indicates a fuel pump primary circuit fault.

DTC 557 indicates a low speed fuel pump primary circuit fault.

Possible causes:
- Open or shorted circuit,
- Damaged Constant Control Relay Module (CCRM).
- Damaged Powertrain Control Module (PCM).

- Key "OFF".

- Disconnected CCRM.

- Measure resistance of CCRM from Pin 18 to Pin 13.

- Is resistance between 65 and 120 ohms?

Yes -- Go to X72. X72 - Check Continuity of Fuel Pump Circuit

No -- Replace CCRM. Remove breakout box. Reconnect PCM. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)