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, SECURITY, MPX-IG and DACC fuse.
CHECK:

Cheek continuity of MPX-B1, SECURITY, MPX-IG and DACC fuse.

OK:

Continuity
1. NG : Replace the failure fuse.
2. OK : Go to next step.
Check voltage between terminals +B1, +B2, ACC, IG+ and E of theft deterrent ECU connector.
PREPARATION:
1. Turn the ignition switch OFF.
2. Disconnect the theft deterrent ECU connector.
CHECK:

Measure voltage between terminals +B1, +B2, and E.

OK:

Voltage: 10 - 14 V

PREPARATION:
1. Turn the ignition switch ON.
2. Disconnect the theft deterrent ECU connector.
CHECK:

Measure voltage between terminals ACC, IG and E.

OK:

Voltage: 10 - 14 V
1. OK : Proceed to next circuit inspection shown on problem symptom table (See PROBLEM SYMPTOMS TABLE ).
2. NG : Go to next step.
Check wire harness and connector between theft deterrent 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 : Check and repair wire harness and connector between theft deterrent ECU and battery.