2008 Lexus LS 600hLFACTORY OEM SERVICE PROCEDURE

Terminals Of Ecu

  1. CHECK FRONT CONTROLLER 
    Fig 1: Identifying A50, A51, A52 And B14 Front Controller Connectors
    G05776777Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the A50 and A52 front controller connectors
    2. Measure the resistance and voltage according to the value (s) in the table below
      CONNECTOR TERMINAL REFERENCE

      Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Condition
      A52-1 (BATB) - A50-2 (E) P - W-B Power source Always 11 to 14 V
      A52-5 (ALTB) - A50-2 (E) L - W-B Power source Always 11 to 14 V
      A50-1 (FMB3) - A50-2 (E) LG - W-B Power source Always 11 to 14 V
      A50-2 (E) - Body ground W-B - Body ground Ground Always Below 1 Ω
      A50-5 (FMIG) - A50-2 (E) Y - W-B Ignition power supply Power switch ON (IG) 11 to 14 V
      Power switch OFF Below 1 V

      If the result is not as specified, there may be a malfunction on the wire harness side.

    3. Reconnect the front controller connectors.
    4. Measure the voltage according to the value (s) in the table below
    CONNECTOR TERMINAL REFERENCE

    Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Condition
    A51-12 (RDEF) - A50-2 (E) W - W-B Defogger relay Power switch ON (IG) Rear defogger switch ON Below 1 V
    Power switch ON (IG) Rear defogger switch OFF 11 to 14 V

    If the result is not as specified, the front controller may have a malfunction.

  2. CHECK AIR CONDITIONING AMPLIFIER 
    Fig 2: Identifying L76 And L77 Air Conditioning Amplifier Connectors
    G04950350Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the L76 and L77 air conditioning amplifier connectors
    2. Measure the resistance and voltage according to the value (s) in the table below
    CONNECTOR TERMINAL REFERENCE

    Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Condition
    L76-5 (IG+) - L76-1 (GND) V - W-B Ignition power supply Power switch ON (IG) 11 to 14 V
    Power switch OFF Below 1 V
    L76-6 (+B1) - L76-1 (GND) L - W-B Battery power source Always 11 to 14 V
    L76-7 (+B2) - L76-1 (GND) L - W-B Battery power source Always 11 to 14 V
    L76-1 (GND) - Body ground W-B - Body ground Ground Always Below 1 Ω
    L76-2 (FGND) - Body ground W-B - Body ground Ground Always Below 1 Ω
    L77-6 (RGND) - Body ground W-B - Body ground Ground Always Below 1 Ω

    If the result is not as specified, there may be a malfunction on the wire harness side.

  3. CHECK DISPLAY AND NAVIGATION ASSEMBLY*1, MULTI-DISPLAY*2, *3 

    HINT:

    • *1 w/ Navigation System (for HDD)
    • *2 w/ Navigation System (for DVD)
    • *3. w/o Navigation System
    Fig 3: Identifying L59 Display Connector
    G04950361Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the L59 display connector.
    2. Measure the resistance and voltage according to the value (s) in the table below.
    CONNECTOR TERMINAL REFERENCE

    Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Condition
    L59-1 (+B1) - L59-10 (GND1) R - W-B Battery power source Always 11 to 14 V
    L59-3 (IG) - L59-10 (GND1) V - W-B Ignition power supply Power switch OFF Below 1 V
    Power switch ON (IG) 11 to 14 V
    L59-10 (GND1) - Body ground W-B - Body ground Ground Always Below 1 Ω

    If the result is not as specified, there may be a malfunction on the wire harness side

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.