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.

READ VALUE OF HAND-HELD TESTER (TRANSPONDER KEY ECU (SWITCH CONDITION))
1. Connect the hand-held tester to the DLC3.
2. Turn the ignition switch to the ON position, and turn the hand-held tester main switch ON.
3. Select the item "ANTENNA COIL" in the DATA LIST, and read its value displayed on the hand-held tester.
  Standard:
  
  OK: NORMAL
  
  NG: FAIL
Result:

Fig 1: Transponder Key ECU (Switch Condition) Chart
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

A: REPLACE TRANSPONDER KEY ECU ASSY

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

C: Go to next step.
CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)
1. Disconnect the T20 ECU and l13 amplifier connectors.
  
  Fig 2: Disconnecting T20 ECU & I13 Amplifier Connectors
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance of the wire harness side connectors.
Standard

Fig 3: Transponder Key ECU Condition Chart
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE TRANSPONDER KEY AMPLIFIER