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Home >> Lincoln >> 1994 >> Mark VIII V8-4.6L DOHC >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Pinpoint Tests >> XB - Variable Control Relay Module (VCRM) >> XB123 - Check HFP Relay and Circuits
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XB123 - Check HFP Relay and Circuits



- Key "OFF".

- Variable Control Relay Module (VCRM) disconnected.

- Disconnect High Speed Fuel Pump (HFP) relay.

- Key "ON".

- Is fuel pump off?

Yes -- Key "OFF". Go to XB124 (to check HFP circuit). XB124 - Check HFP Circuit For Short to Ground

No -- Key "OFF". Service short to power in power-to-pump / Fuel Pump Monitor (FPM) circuit. Reconnect all components. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)
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