Diagnosis & Repair
WARNING: This page is about a different car, the 2002 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.
- Turn ignition off. Access ECM and body ECU behind glove box. See Figure. Disconnect ECM harness connector E5. See Figure. Disconnect body ECU harness connector B10. See Fig 1. Disconnect instrument cluster harness connector C12. See Fig 2. Check continuity in Yellow wire between terminal No. 11 at ECM harness connector E5 and terminal No. 6 at body ECU harness connector B10. Check continuity in Blue/White wire between terminal No. 18 at ECM harness connector E5 and terminal No. 9 at instrument cluster harness connector C12. If continuity exists in both wires, go to next step. If continuity does not exist in either wire, repair wiring as necessary.
- Connect all disconnected components. Turn ignition on. Using a DVOM, backprobe ECM harness connector and measure voltage between ground and terminals No. 1 (Black/White wire) and No. 16 (White wire) at ECM harness connector E5. If battery voltage exists at both terminals, go to next step. If battery voltage does not exist at either terminal, repair power distribution circuit(s) as necessary. See WIRING DIAGRAMS article.
- Turn ignition off. Using a DVOM, backprobe ECM harness connector and check continuity between ground and terminal No. 17 (Brown wire) at ECM harness connector E8. If continuity exists, replace ECM. If continuity does not exist, repair wiring as necessary. See WIRING DIAGRAMS article.