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 Control Test
When ignition is turned on, EEC power relay is energized, closing its contacts. Power is provided to both fuel pump relay and a timing device in EEC module. Fuel pump runs through contacts of fuel pump relay. If ignition is not turned on within 1 second, timing device in EEC module will create an open ground circuit.
Opening ground circuit de-energizes fuel pump relay (opening its contacts), which in turn de-energizes fuel pump. This circuitry provides for pre-pressurization of fuel system. When ignition switch is turned to "START" position, EEC module operates fuel pump relay to provide fuel for starting engine while cranking.
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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.