Inspection Procedure

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

Check wire harness.
PREPARATION:

Disconnect the connectors of the wireless door lock tuner and theft deterrent ECU.

CHECK:

Check continuity between terminals DATA of the wireless door lock tuner and RDA of the theft deterrent ECU.

OK:

Continuity

HINT:

Check the wire harness that has communication malfunction.

Fig 1: Checking Continuity Between Terminals DATA Of Wireless Door Lock Tuner And RDA Of Theft Deterrent ECU
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG : Repair or replace wireless door lock tuner.
2. OK : Go to next step.
Check theft deterrent ECU.
PREPARATION:

Connect the connector of the theft deterrent ECU.

CHECK:

Check the DTC.

OK:

B1242 is not output.

Fig 2: Connecting Connector Of Theft Deterrent ECU
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG : Replace theft deterrent ECU (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
2. OK : Replace wireless door lock tuner.