LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2007 >> RX 400h FWD >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> SFI System >> MIL Circuit >> Inspection Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Inspection Procedure

HINT:

Troubleshoot each trouble symptom in accordance with the chart below.

TROUBLE SYMPTOM CHART

MIL remains illuminated Start inspection from step  1
MIL not illuminated Start inspection from step  3
  1. CHECK WHETHER MIL TURNS OFF 
    1. Connect the intelligent tester to the DLC3.
    2. Turn the ignition switch to the ON position.
    3. Turn the tester ON.
    4. Check whether any DTCs have been stored (See DTC CHECK / CLEAR ). Note them down if necessary.
    5. Clear the DTCs (See DTC CHECK / CLEAR ).
    6. Check if the MIL turns off.

      OK: MIL should turn off. 

    OK: REPAIR CIRCUIT INDICATED BY OUTPUT DTC 

    NG: Go to next step 

  2. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT IN WIRE HARNESS) 
    1. Disconnect the H29 HV control ECU connector.
    2. Turn the ignition switch to the ON position.
    3. Check the MIL is not illuminated.

      OK: MIL is not illuminated. 

    4. Reconnect the HV control ECU connector.

    OK: REPLACE HV CONTROL ECU 

    Fig 1: Identifying H29 HV Control ECU Connector
    G05275757Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: CHECK AND REPAIR HARNESS AND CONNECTOR (COMBINATION METER - HV CONTROL ECU) 

  3. CHECK THAT MIL IS ILLUMINATED 
    1. Check if the MIL is illuminated when the ignition switch is turned on.

      OK: MIL should be illuminated. 

    OK: SYSTEM OK 

    NG: Go to next step 

  4. INSPECT COMBINATION METER ASSEMBLY (MIL CIRCUIT) 
    1. See the combination meter troubleshooting procedure (See PROBLEM SYMPTOMS TABLE ).

    NG: REPAIR OR REPLACE BULB OR COMBINATION METER ASSEMBLY 

    OK: CHECK AND REPAIR HARNESS AND CONNECTOR (COMBINATION METER - HV CONTROL ECU)