How To Proceed With Troubleshooting

2009 Toyota Sienna XLE, FWDSECTION How To Proceed With Troubleshooting

HINT:

  • Use this procedure to troubleshoot the front power seat control system.
  • Techstream should be used in steps 3 and 5.
  1. VEHICLE BROUGHT TO WORKSHOP 
  2. CUSTOMER PROBLEM ANALYSIS CHECK AND PROBLEM SYMPTOM CHECK 
  3. CHECK COMMUNICATION FUNCTION OF MULTIPLEX COMMUNICATION SYSTEM (BEAN) 
    1. Use Techstream to check for normal function of the multiplex communication system.
      1. (Position control ECU and switch assembly (power seat control switch and ECU) not connected, communication line malfunctioning) If no code is output, proceed to A.
      2. (Position control ECU and switch assembly (power seat control switch and ECU) not connected, communication line malfunctioning) If any code is output, proceed to B.

    B:  Go to MULTIPLEX COMMUNICATION SYSTEM

    A: Go to next step 

  4. PROBLEM SYMPTOMS TABLE 
    1. If the fault is not listed on the problem symptoms table, proceed to A.
    2. If the fault is listed on the problem symptoms table, proceed to B.

    B: Go to step 6 

    A: Go to next step 

  5. OVERALL ANALYSIS AND TROUBLESHOOTING 
    1. DATA LIST / ACTIVE TEST .
      1. Inspection with Techstream (DATA LIST).
      2. Inspection with Techstream (ACTIVE TEST).
    2. TERMINALS OF ECU .
    3. Inspection.
  6. ADJUST, REPAIR OR REPLACE 
  7. CONFIRMATION TEST 

    NEXT: END 

RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

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

Affiliate disclosure: We may earn a commission at no extra cost to you.

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.