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 operation of pad switch. (Check whether or not audio system can be operated with radio and player.)
1. NG : Go to step 4 .
2. OK : Go to next step.
Check wire harness between steering pad switch and TEL ECU.
PREPARATION:

Disconnect the steering pad switch and TEL ECU connectors.

CHECK:

Check continuity of the wire harness between terminal TLSW (1) of the steering pad switch and terminal TSW+ of the TEL ECU.

OK:

Continuity
1. NG : Replace or repair wire harness or connector (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
2. OK : Go to next step.
Check TEL ECU.
PREPARATION:

Disconnect the TEL ECU connector.

CHECK:

Check continuity at terminal TSW-.

OK:

Continuity
1. Replace or repair wire harness (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
2. OK : Replace TEL ECU.
Service check mode (Gateway ECU) (See PRE-CHECK ).
1. OK : Check gateway system (Steering pad switch) (See GATEWAY SYSTEM - DIAGNOSIS ).
2. NCON: Go to next step.
Check gateway ECU.
PREPARATION:

Disconnect the gateway ECU connector.

CHECK:

Check the voltage of terminal +B.

OK:

+B: 10 - 14 V

CHECK:

Check the voltage of terminal ACC when the ignition switch is in ACC or ON position.

OK:

ACC: 10 - 14 V

CHECK:

Check continuity at terminal GND.

OK:

GND: Continuity
1. NG : Replace or repair wire harness or connector (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
2. OK : Replace steering pad switch (See REMOVAL ).