Operation CHARM: Car repair manuals for everyone.

X166 - Check LFP Relay



- Key "OFF".

- Low Speed Fuel Pump (LFP) relay disconnected.

- Digital Volt/Ohm Meter (DVOM) on 200 ohm scale.

Fuel Pump Relay Connector:






- Measure LFP relay coil resistance between the LFP pin and VPWR pin at the fuel pump relay. Resistance should be between 40 and 85 ohms.

- DVOM on 10,000 ohm scale.

- Check LFP relay for internal shorts: Measure resistance between the LFP pin and both the power-to-pump and B(+) pins. Both resistances should be greater than 10,000 ohms.

- Are all resistance checks OK?

Yes -- Go to X167. X167 - Check LFP Circuit For Short to Power

No -- Replace LFP relay. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)