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Test No. 1: Ignition Switch Does Not Operate In Each Position

  1. Check ignition switch. See IGNITION SWITCH  under COMPONENT TESTS. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch. See IGNITION SWITCH  under REMOVAL & INSTALLATION.
  2. Power source for Body Electronic Control Unit (ECU) should be checked. Check the following fuses: ECU-ACC (5-amp), DOOR No. 1 (25-amp), ECU-IG No. 2 (10-amp) and ECU-B (7.5-amp). These fuses are located in the fuse/relay box at driver's side of instrument panel. See Figure. Also, check DOOR No. 2 fuse (15-amp). DOOR No. 2 fuse is located in fuse/relay box at driver's side front corner of engine compartment. See Figure. If all fuses are okay, go to next step. If any fuse is defective, replace fuse and repair wiring harness or electrical connector on wiring circuit as necessary. See WIRING DIAGRAMS .
  3. Note location of body ECU at driver's side of instrument panel on the fuse/relay box. See Fig 1. Electrical connector B4 (25-pin) and electrical connector B5 (25-pin) are located at each side of body ECU and a 12-pin electrical connector at rear of body ECU. See Fig 1.
  4. Turn ignition on. Using voltmeter, check voltage between ground circuit at terminal No. 14 (White/Black wire: GND1 terminal) at electrical connector B5 and terminals No. 1 (BDR1 terminal), No. 2 (SIG terminal) and No. 3 (ACC terminal) at the 12-pin electrical connector. See Fig 1. Also, check voltage between ground circuit at terminal No. 11 (White/Black wire: GND2 terminal) at electrical connector B4 and terminals No. 1 (BDR1 terminal), No. 2 (SIG terminal) and No. 3 (ACC terminal) at the 12-pin electrical connector. See Fig 1. Voltage should be 10-14 volts. Go to next step.
  5. Turn ignition off. Disconnect electrical connectors at body ECU. Using voltmeter, check voltage between ground circuit at terminal No. 14 (White/Black wire: GND1 terminal) at electrical connector B5 and terminal No. 24 (White/Green wire; "B"terminal) at electrical connector B4 and terminal No. 7 (BDR2 terminal) at the 12-pin electrical connector. See Fig 1. Also, check voltage between ground circuit at terminal No. 11 (White/Black wire: GND2 terminal) at electrical connector B4 and terminal No. 24 (White/Green wire; "B"terminal) at electrical connector B4 and terminal No. 7 (BDR2 terminal) at the 12-pin electrical connector. See Fig 1. Voltage should be 10-14 volts. Go to next step.
  6. If all voltage readings are within specification, reinstall electrical connectors and go to SYMPTOM INDEX (BODY CONTROL SYSTEM)  table and diagnosis by symptom. If any voltage is not within specification, check for open in wiring harness and electrical connectors between ground connections and terminal No. 11 at electrical connector B4 and terminal No. 14 at electrical connector B5. See WIRING DIAGRAMS . If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
  7. Check wiring harness and electrical connectors between battery, ignition switch and body ECU. See WIRING DIAGRAMS . For additional wiring for power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS. Repair wiring harness or electrical connector as necessary and recheck system operation.
    Fig 1: Locating Body Electronic Control Unit & Identifying Electrical Connectors
    G00015630Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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