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.
Circuit Description
When ignition switch is turned on, 9-14 volts is applied to terminal IGSW at ECM. EFI relay control circuit in ECM then sends a signal to terminal MREL at ECM to switch EFI relay on. This signal causes current to flow to coil, closing contacts of EFI relay and supplying power to terminal +B of ECM. If ignition switch is turned off, ECM continues to switch on EFI relay for a maximum of 2 seconds for initial setting of throttle valve.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.