Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT FUSE (MPX-B1, SECURITY, MPX-IG, AM1, D-ACC, D/C CUT H-)
1. Remove the MPX-B1 fuse from the passenger side J/B.
2. Remove the SECURITY, MPX-IG, AM1 and D-ACC fuses from the driver side J/B.
3. Remove the D/C CUT H-fuse from the FL block assy.
4. Measure the resistance.
  Standard: Below 1 Ω
  
  NG: REPLACE FUSE
  
  OK: Go to next step.
INSPECT RELAY (D-IG1, D-ACC)
1. Remove the D-IG1 and D-ACC relays from the driver side J/B.
2. Measure the resistance.
  Standard:
  
  Fig 1: Inspecting Relay (D-IG1, D-ACC)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 2: Identifying Terminals Resistance Specification Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  NG: REPLACE RELAY
  
  OK: Go to next step
CHECK WIRE HARNESS (THEFT WARNING ECU ASSY - BODY GROUND)
1. Disconnect the T5 ECU connector.
2. Measure the resistance and voltage between the wire harness side connector and body ground.
  Standard:
  
  Fig 3: Checking Wire Harness (Theft Warning ECU Assy - Body Ground)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 4: Identifying Terminals Voltage And Resistance Specification Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  NG: REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR
  
  OK: Go to next step
  
  PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See PROBLEM SYMPTOMS TABLE )