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-B3 and MPX-IG fuse.
CHECK:

Check continuity of MPX-B3 and MPX-IG fuse.

OK:

Continuity
1. NG : Replace the failure fuse.
2. OK : Go to next step.
Check voltage between terminal B, IG and E of combination switch.
PREPARATION:

Disconnect the combination switch.

CHECK:

Measure voltage between terminals B and E of the combination switch.

OK:

Voltage: 10 - 14 V

PREPARATION:
1. Turn the ignition switch ON.
2. Disconnect the combination switch.
  CHECK:
  
  Measure voltage between terminals IG and E of combination switch.
  
  OK:
  
  Voltage: 10 - 14 V
1. OK : Proceed to next circuit inspection shown on problem symptoms table (See PROBLEM SYMPTOMS TABLE ).
2. NG : Go to next step.
Check wire harness and connector between combination switch 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 ECU and battery.