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 MPX-B1 and IG2 fuse.
CHECK:

Check continuity of MPX-B1 and IG2.

OK:

Continuity
1. NG : Replace the failure fuse.
2. OK : Go to next steps.
Check voltage between terminals IG, CPUB and GND of transponder key ECU connector.
PREPARATION:

Turn the ignition switch ON.

CHECK:

Measure voltage between terminals IG and GND.

OK:

Voltage: 10 - 14 V

PREPARATION:
1. Turn the ignition switch OFF.
2. Disconnect the transponder key ECU connector.
CHECK:

Measure voltage between terminals CPUB and GND.

OK:

Voltage: 10 - 14 V
1. OK : Proceed to next circuit inspection shown in problem symptoms table (See PROBLEM SYMPTOMS TABLE ).
2. NG : Go to next steps.
Check wire harness and connector between transponder key ECU and body ground (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
1. NG : Repair or replace wire harness or connector.
2. OK : Proceed to next circuit inspection shown on problem symptom table (See PROBLEM SYMPTOMS TABLE ).