2008 Toyota Sequoia SR5, 5.7 Y, RWDFACTORY OEM SERVICE PROCEDURE

Inspection Procedure

NOTE: When replacing the VSC actuator assembly, perform zero point calibration (See CALIBRATION  ).

HINT:

If the transfer shift actuator cannot change from 2WD to 4WD or 4WD to 2WD or cannot lock the center differential, inspect and repair the touch select 2-4 and high-low systems first.

  1. INSPECT SKID CONTROL ECU (EXI2 TERMINAL) 
    1. Disconnect the A19 ECU connector.
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      A19-6 (EXI2) - Body ground 4WD with center differential locked (Center differential lock detection switch ON) Below 1.5 V
      A19-6 (EXI2) - Body ground 2WD or 4WD with center differential free (Center differential lock detection switch OFF) 10 to 14 V

    NG: Go to step 2 

    Fig 1: Identifying A19 ECU Connector Terminal
    G05649550Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE VSC ACTUATOR ASSEMBLY  (See REMOVAL  )

  2. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - 4WD CONTROL ECU) 
    1. Confirm that the skid control ECU connector and 4WD control ECU connector are properly connected.
    2. Disconnect the A19 and A28 ECU connectors.
    3. Inspect both the connector case and the terminal for deformation and corrosion.

      OK: No deformation or corrosion. 

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      RESISTANCE REFERENCE

      Tester Connection Condition Specified Condition
      A19-6 (EXI2) - A28-14 (4WD) Always Below 1 Ω
      A19-6 (EXI2) - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 2: Identifying A19 And A28 ECU Connector Terminal
    G05649551Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  3. CHECK HARNESS AND CONNECTOR (4WD CONTROL ECU - BODY GROUND) 
    1. Confirm that the 4WD control ECU connector and shift actuator connectors are properly connected.
    2. Disconnect the A28 ECU connector.
    3. Inspect the connector case and the terminal for deformation and corrosion.

      OK: No deformation or corrosion. 

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      RESISTANCE REFERENCE

      Tester Connection Condition Specified Condition
      A28-14 (4WD) - Body ground 4WD with center differential locked (Center differential lock detection switch ON) Below 1 Ω
      2WD or 4WD with center differential free (Center differential lock detection switch OFF) 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 3: Identifying A28 ECU Connector Terminal
    G05649552Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  4. RECONFIRM DTC 
    1. Clear the DTC(s) (See DTC CHECK/CLEAR  ).
    2. Start the engine.
    3. Check if the same DTC(s) is output (See DTC CHECK/CLEAR  ).

      Result 

      RESULT REFERENCE

      Result Proceed to
      DTC is output A
      DTC is not output B

    B: CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)  (See HOW TO PROCEED WITH TROUBLESHOOTING )

    A: REPLACE 4WD CONTROL ECU  (See REMOVAL )

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.