Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Fuel Pump Relay & Fuel Pump Resistor
Fuel pump speed is controlled at low speed or high speed depending on if engine is cranking or engine load. When engine is cranking, circuit opening relay is energized and provides full battery voltage to fuel pump relay. Fuel pump relay delivers full battery voltage to fuel pump and fuel pump operates at high speed. When start signal is released and engine is idling or under light load, ECM then grounds the fuel pump relay at ECM terminal FPR. Fuel pump relay closes and provides voltage through the fuel pump resistor to the fuel pump. Fuel pump now operates at low speed.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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