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.
Computer Controlled Shutdown
The PCM controls the PCM power relay when the ignition is turned to the ON or START position, by grounding the PCMRC circuit. After the ignition is turned to the OFF, ACC or LOCK position, the PCM stays powered up until the correct engine shutdown occurs.
The ISP-R circuit provides the ignition state input to the PCM. Based on the ISP-R signal the PCM determines when to power down the PCM power relay.
The PCM software monitors the parameters for the controlled systems to make sure that all values have met a threshold for shutdown.
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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.