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.
Driver's Multiplex Control Unit Input
Turn ignition switch to OFF position. Remove driver's underdash fuse/relay box located under instrument panel. See DRIVER'S UNDERDASH FUSE/RELAY BOX under REMOVAL & INSTALLATION. Disconnect driver's multiplex control unit from underdash fuse/relay box. Disconnect driver's multiplex control unit connectors. Inspect connectors and terminals. Check for bent, loose or corroded terminals. Repair connector terminals as necessary and retest system. Perform driver's multiplex control unit input tests. See Fig 1 . If driver's multiplex control unit input tests are okay, replace faulty driver's multiplex control unit.
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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.