LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2001 >> Sienna XLE >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Systems >> System Tests >> Test No. 1: Ignition Switch Does Not Operate In Each Position
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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. Body ECU may also be referred to as integration relay. Check the following fuses: DOOR (25-amp), GAUGE (10-amp) and POWER (30-amp). These fuses are located in the fuse/relay box at driver's side of instrument panel. See Figure. Also, check DOME fuse (10-amp). DOME 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 . For additional wiring for power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS.
  3. Check power relay. See POWER RELAY  under COMPONENT TESTS. If power relay is okay, go to next step. If power relay is defective, replace power relay and recheck ignition switch operation.
  4. Note location of body ECU at driver's side of instrument panel on the fuse/relay box. See Figure. Body ECU may also be referred to as integration relay. Electrical connector I13 (7-pin or 25-pin) and electrical connector I16 (18-pin) are located at body ECU and a 12-pin electrical connector is located at rear of body ECU. See Figure.
  5. Turn ignition on. Using voltmeter, check voltage between terminal No. 7 (IG terminal) and ground circuit at terminal No. 10 ("E" terminal) at body ECU 12-pin electrical connector. See Figure. Voltage should be 10-14 volts. Go to next step.
  6. Turn ignition off. Disconnect electrical connectors at body ECU. Using voltmeter, check voltage between terminal No. 1 ("B" terminal) and ground circuit at terminal No. 10 ("E" terminal) at body ECU 12-pin electrical connector. See Figure. Voltage should be 10-14 volts. On models with power door locks, using voltmeter, check voltage between ground circuit at terminal No. 10 ("E" terminal) at body ECU 12-pin electrical connector and terminals No. 15 (Blue/White wire) and No. 24 (Black/Red wire) at body ECU electrical connector I13. See Figure. Voltage should be 10-14 volts.
  7. On all models, if all voltage readings are within specification, reinstall electrical connectors and go to SYMPTOM INDEX  table and diagnosis by additional symptoms. If any voltage is not within specification, check for open in wiring harness and electrical connectors between ground connection and terminal No. 10 at body ECU 12-pin electrical connector. 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.
  8. 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.
scientia non olet · About LEMON Manuals