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.
Control Unit
PCM is located below center console.
PCM analyzes all electrical data signals from input devices to control fuel injection, ignition and emissions. PCM includes a back-up fail-safe control system. If a malfunction develops in PCM microcomputer, back-up control system will maintain necessary engine functions to permit operation of vehicle.
PROM is factory-programmed engine calibration data, which modifies PCM for specific transmission, engine, emission, vehicle weight and rear axle ratio application. EEPROM (Electronically Erasable Programmable Read Only Memory) provides fuel delivery back-up so engine runs in case of PROM or PCM failure. Anytime PCM is replaced, install original PROM and/or EEPROM into replacement PCM. If battery voltage is removed, PROM and EEPROM information is retained.
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.