Toyota Sienna Quiz
Seat

Problem symptoms table

In this manual: Seat
Introduction — 55Service specifications — 7Maintenance — 7Engine — 264U151e automatic transaxle — 108Transfer — 19Propeller shaft — 8Drive shaft — 14Differential — 16Axle — 18Suspension — 37Tire and wheel — 54Brake control — 141Parking brake — 16Steering Column — 11Power steering — 18Air conditioning — 106Supplemental restraint system — 146Seat belt — 22Theft deterrent — 14Engine immobiliser — 17Cruise control — 65Lighting — 61Wiper and washer — 13Door lock — 42Meter — 28Audio / visual — 94Navigation — 108Park assist / monitoring — 33Horn — 5Garage door opener — 42GR-FE Engine control system — 126Supplemental restraint system — 147Other system — 14Windshield / windowglass — 43Mirror — 23Instrument panel — 6Seat belt — 22Seat — 92Engine hood / door — 104Exterior — 39Interior — 5Sliding roof — 9Multiplex communication — 18Can communication — 23
31steps
~186min
4/5difficulty
Done 0 of 31

HINT:

  • Inspect the fuse and relay before confirming the suspected areas in the table below.
  • Inspect each suspected area in numerical order for the corresponding symptom.

If the malfunction still exists after checking and confirming that all circuits and components are normal, replace the ECU.

FRONT POWER SEAT CONTROL SYSTEM ( w/o MEMORY)

Symptom

Suspected area
Power seat does not operate (slide, front vertical, lifter, reclining).
  1. P/SEAT fuse
  2. Power seat switch
  3. Wire harness or connector
Slide operation function only does not operate.
  1. Power seat switch
  2. Front seat frame with adjuster (LH side slide motor)
  3. Front seat frame with adjuster (RH side slide motor)
  4. Wire harness or connector
Front vertical operation function only does not operate.
  1. Power seat switch
  2. Front seat frame with adjuster (LH side front vertical motor)
  3. Wire harness or connector
Lifter operation function only does not operate.
  1. Power seat switch
  2. Front seat frame with adjuster (LH side lifter motor)
  3. Wire harness or connector
Reclining operation function only does not operate.
  1. Power seat switch
  2. Front seat frame with adjuster (LH side reclining motor)
  3. Front seat frame with adjuster (RH side reclining motor)
  4. Wire harness or connector
Lumbar support operation function only does not operate (Driver side only).
  1. Front power seat lumbar switch
  2. Lumbar support adjuster assembly
  3. Wire harness or connector

FRONT POWER SEAT CONTROL SYSTEM ( w/ MEMORY)

Symptom

Suspected area
Power seat does not operate (manual or memorized position).
  1. ECU power source circuit
  2. Position control ECU and switch assembly (power seat control switch and ECU)
One of the power seat functions does not operate (manual or memorized position).
  1. Power seat motor circuit
  2. Position control ECU and switch assembly (power seat control switch and ECU)
One or all manual seat functions do not operate (memorized positions OK).
  1. Position control ECU and switch assembly (power seat control switch
Memory function does not operate.
  1. Memory switch circuit
  2. Multiplex communication system
  3. Position control ECU and switch assembly (power seat control switch
No memory functions operate or all memory functions operate briefly
  1. ECU power source circuit
  2. Position control ECU and switch assembly (power seat control switch
One memory function does not operate or operates briefly and then stops
  1. Front seat frame with adjuster (power seat motor)
  2. Position control ECU and switch assembly (power seat control switch

Test yourself

A quick Toyota Sienna quiz: every answer comes with an explanation and a link to the manual page.