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.
2002 Acura 3.5RLFACTORY OEM SERVICE PROCEDURE
Driver's Multiplex Control Unit
- Remove driver's underdash fuse/relay box. See DRIVER'S UNDERDASH FUSE/RELAY BOX under REMOVAL & INSTALLATION. Remove driver's multiplex control unit from driver's underdash fuse/relay box. Disconnect control unit connectors. Inspect connectors and terminals. Check for bent, loose, or corroded terminals. Perform first part of driver's multiplex control unit input tests. See Fig 1 . Repair as necessary and recheck system operation. If driver's multiplex control unit inputs are okay, go to next step.
- Reconnect driver's multiplex control unit to underdash fuse/relay box. Perform second part of input tests at back of fuse/relay box (backprobe). See Fig 1 . Repair as necessary.
- If all tests have proven okay, driver's multiplex control unit must be faulty. Replace driver's multiplex control unit and recheck system operation.
Factory Service Tools
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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.