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 3.2TL BaseFACTORY OEM SERVICE PROCEDURE
Multiplex Control Unit: 3.5RL
- Remove driver's underdash fuse/relay box. See DRIVER'S UNDERDASH FUSE/RELAY BOX (3.5RL) under REMOVAL & INSTALLATION. Remove driver's multiplex control unit from underdash fuse/relay box. Disconnect control unit connectors. Inspect connectors and terminals. Check for bent, loose, or corroded terminals. Perform 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, control unit may be faulty. Substitute known-good driver's multiplex control unit and retest system. If problem is still present, reinstall original control unit and go to next step.
- Remove driver's door panel. See DOOR PANEL under REMOVAL & INSTALLATION. Remove door multiplex control unit (built into power window switch). Disconnect control unit connector. Inspect connectors and terminals. Check for bent, loose or corroded terminals. Perform first part of door multiplex control unit input test. See Fig 2 . Repair as necessary and recheck system operation. If door multiplex control unit tests are okay, go to next step.
- Reconnect door multiplex control unit connector. Perform second part of door multiplex control unit input test at back of door multiplex control unit connector (backprobe). See Fig 2 . Repair as necessary. If all input tests are okay, control unit may be faulty. Substitute known-good door multiplex control unit and retest system. If problem is still present, reinstall original control unit and go to next step.
- Remove passenger's multiplex control unit from behind right kick panel. Disconnect control unit connectors. Inspect connectors and terminals. Check for bent, loose or corroded terminals. Perform first part of passenger's multiplex control unit input test. See Fig 3 . Repair as necessary and recheck system operation. If passenger's multiplex control unit inputs are okay, go to next step.
- Reconnect passenger's multiplex control unit. Perform second part of input test at back of passenger's multiplex control unit connectors (backprobe). See Fig 3 . Repair as necessary. If all tests are okay, control unit may be faulty. Substitute known-good passenger's multiplex control unit and retest system.
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.
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