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.
Dual Relay
The dual relay is composed of 2 relays which control current supply for entire electronic fuel injection system and which disengages system (electrically) from battery when ignition is turned off. When ignition switch is on, the main relay points close, providing voltage to the ECU and pre-resistors (if used) of the electronic fuel injection system.
The other relay within the dual relay, controls current to the electric fuel pump. These points close during cranking and when points of air flow valve are closed. This design is to cut off current to fuel pump in the event that engine stops (airflow meter closed).
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.