Test No. 1: Ignition Switch Does Not Operate In Each Position
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 ignition switch. See IGNITION SWITCH under COMPONENT TESTS under STEERING COLUMN SWITCHES - AVALON article in ACCESSORIES & EQUIPMENT. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
- Check power source for body control ECU by first checking the following fuses located in driver side junction block: ECU-ACC (5-amp), ECU-IG No. 2 (10-amp), DOOR No. 1 (25-amp) and ECU-B (7.5-amp). Check DOOR No. 2 (15-amp) fuse located in engine compartment junction block. See BODY COMPUTER in SYSTEM WIRING DIAGRAMS article. Check DCC (30-amp) fuse located in engine compartment junction block. See POWER DISTRIBUTION in SYSTEM WIRING DIAGRAMS article. If all fuses are okay, go to next step. If any fuse is defective, replace fuse and repair wiring harness or electrical connector of affected circuit as necessary. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .
- Turn ignition off. Remove body control ECU from driver side junction block under left side of instrument panel. See Fig 1. DO NOT disconnect 25-pin electrical connectors B4 or B5 from body control ECU. The 12-pin driver side junction block-to-body control ECU connector is only accessible with body control ECU removed from junction block. See Fig 1.
- Turn ignition on. Using DVOM, check voltage by backprobing with negative lead at ground circuit GND1 (White/Black wire) of 25-pin body control ECU connector B5 terminal No. 14 and probing 12-pin driver side junction block-to-body control ECU connector on driver side junction block with positive lead at terminals No. 1 (BDR1), No. 2 (SIG) and No. 3 (ACC). Perform same check with negative lead at ground circuit GND2 (White/Black wire) of 25-pin body control ECU connector B4 terminal No. 11 and probing 12-pin driver side junction block-to-body control ECU connector on driver side junction block with positive lead at terminals No. 1 (BDR1), No. 2 (SIG) and No. 3 (ACC). See Fig 1. See BODY COMPUTER in SYSTEM WIRING DIAGRAMS article. Voltage should be 10-14 volts at all test points. Go to next step.
- Turn ignition off. Disconnect 25-pin body control ECU connectors B4 and B5. Check voltage with negative lead at ground circuit GND1 (White/Black wire) of 25-pin body control ECU connector B5 terminal No. 14 and positive lead at battery circuit "B" (White/Green wire) of 25-pin body control ECU connector B4 terminal No. 24 and then terminal No. 7 (BDR2) of 12-pin driver side junction block-to-body control ECU connector on driver side junction block. Perform same check with negative lead at ground circuit GND2 (White/Black wire) of 25-pin body control ECU connector B4 terminal No. 11 and positive lead at battery circuit "B" (White/Green wire) of 25-pin body control ECU connector B4 terminal No. 24 and then terminal No. 7 (BDR2) of 12-pin driver side junction block-to-body control ECU connector on driver side junction block. See Fig 1. See BODY COMPUTER in SYSTEM WIRING DIAGRAMS article. Voltage should be 10-14 volts. Go to next step.
- If all voltage readings are within specification, reinstall electrical connectors and diagnosis by symptom. If any voltage reading is not within specification, check and repair ground circuits and electrical connectors (GND1 and GND2; White/Black wires) between body control ECU 25-pin connector B5 terminal No. 14 and 25-pin body control ECU connector B4 terminal No. 11. See BODY COMPUTER in SYSTEM WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step.
- Check and repair power circuits and electrical connectors between battery, ignition switch and body ECU. See BODY COMPUTER in SYSTEM WIRING DIAGRAMS article. For additional wiring for power supply circuit, see POWER DISTRIBUTION in SYSTEM WIRING DIAGRAMS article. Repair wiring harness or electrical connector as necessary. After repairs have been made, perform confirmation test. See CONFIRMATION TEST .