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.
Fault Memory
Both the FICU and ICU store faults for self-diagnosis. If a fault occurs, the computer memory will store a code and corrective action will take place. For example: the coolant temperature sensor develops an open circuit. In this case, both control units will assume a calculation value of a fully warmed engine.
The fault will be displayed by a flashing of the engine control indicator light. By inserting a fuse into the top of the fuel relay for 4 seconds, the diagnostic terminals will be grounded and the memories will be displayed by a flashing sequential code on the instrument cluster.
If the ignition system is operating in a fully retarded position because of engine knock or a problem has developed in the knock sensor system the indicator light will flash while driving.
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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.