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Test Procedure

  1. Disconnect the anti-theft ECU connector. Measure the voltage between ground and terminal +B1 (T6-2) of anti-theft ECU connector. See Fig 1. If voltage is 10-14 volts, go to UNLOCK WARNING SWITCH CIRCUIT (KEY UNLOCK WARNING SYSTEM) under POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE - ES 300 article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT. If the voltage is not 10-14 volts, go to the next step.
  2. Check the continuity between terminal E (T6-11) of the anti-theft ECU and body ground. See Fig 2. If continuity exists, check and replace the anti-theft warning ECU assembly. If continuity does not exist, repair and replace wire harness or connector as necessary.
Fig 1: Identifying Anti-Theft ECU Connector Terminal +B1
G00191808Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 2: Identifying Anti-Theft ECU Connector Terminal E
G00191809Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002