Toyota Sienna Service Manual: Problem symptoms table

Toyota Sienna Service Manual / Seat / Front power seat control system / Problem symptoms table

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

FRONT POWER SEAT CONTROL SYSTEM ( w/ MEMORY)

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

How to proceed with troubleshooting

HINT: Use this procedure to troubleshoot the front power seat control system. The intelligent tester should be used in steps 3 and 5. 1 VEHICLE BROUGHT TO WORKSHOP 2 CUSTOMER P ...

Terminals of ECU

1. POSITION CONTROL ECU AND SWITCH ASSEMBLY (POWER SEAT CONTROL SWITCH AND ECU) Disconnect the P58 and P59 connectors. Check the voltage of each terminal of the wire harness sid ...

Other materials:

DRL Relay Circuit
DESCRIPTION The Multiplex network body ECU controls the DRL No.2 relay WIRING DIAGRAM INSPECTION PROCEDURE 1 PERFORM ACTIVE TEST BY INTELLIGENT TESTER Connect the intelligent tester to DLC3. Turn the ignition switch ON and push the intelligent tester main switch ON. Sel ...

Using the radio
Radio operation Select “AM” or “FM” on the audio source selection screen to begin listening to the radio. Audio control screen Pressing the “AUDIO” button displays the audio control screen from any screens of the selected source. Audio source selection screen appears Pre ...

Reassembly
1. INSTALL RACK STEERING PISTON RING (a) Coat a new O-ring with power steering fluid and install it onto the power steering rack. (b) Expand a new rack steering piston ring with your fingers. NOTICE: Be careful not to over expand the rack steering piston ring. (c) Coat a new rack steer ...