Test No. 9: Only One Manual Or Return Function Does Not Operate
WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
- Check power seat motors. See POWER SEAT MOTORS under COMPONENT TESTS. If power seat motors are okay, go to next step.
- Disconnect 10-pin electrical harness connector P20 from power seat ECU. Disconnect suspect power seat motor 2-pin electrical harness connector. Using an ohmmeter, check for opens and shorts in wiring harnesses and electrical connectors between power seat ECU and suspect power seat motor. See MEMORY SYSTEMS in SYSTEM WIRING DIAGRAMS article. If wires, wiring harness and connectors are okay, go to next step. If wires, wiring harness and connectors are not okay, repair and/or replace as required. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
- Check power seat ECU ground circuits. If ground circuit resistance is greater than one ohm, repair or replace ground circuit. If ground circuit is okay, substitute original power seat ECU with a known-good unit and recheck manual switch operation of power seat system. If manual switch operation of power seat system operates properly, original power seat ECU was defective. If manual switch operation of power seat system still does not operate properly, perform power seat ECU pin voltage check. See PIN VOLTAGE TESTS . Check wiring harness and electrical connectors for an intermittent problem. Repair wiring harnesses or connectors as necessary. If voltage values, harnesses and connectors are okay, replace power seat ECU. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .