Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT TRANSPONDER KEY ECU ASSY
1. Disconnect the T20 ECU connector.
  
  Fig 1: Disconnecting T20 ECU Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance of the wire harness side connector.
  Standard
  
  Fig 2: Measuring Resistance Between GND & Body Ground Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure the voltage of the wire harness side connectors.
  Standard
  
  Fig 3: Measuring Voltage Between GND Terminals Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS TABLE (See PROBLEM SYMPTOMS TABLE )