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.
Main Relay
Main relay is located in underhood fuse/relay box located at right front corner of engine compartment. On all models, the main relay supplies power to the ECM, fuel injectors (8 amps) and Mass Airflow (MAF) sensor (4 amps). Relay is controlled by the ECM which has a second power feed. This enables the ECM to remain powered up after the ignition is turned off. During ECM power down, the ECM records all temperature readings and powers the Idle Air Control (IAC) valve to the cold start position. Failure of this relay will result in the ECM not being powered up, resulting in engine not starting due to absence of fuel and ignition.
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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.