Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2012 Toyota Sienna SEFACTORY OEM SERVICE PROCEDURE
Problem Symptoms Table
HINT:
- Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
- Inspect the fuses and relays related to this system before inspecting the suspected areas below.
POWER WINDOW CONTROL SYSTEM
| Symptom | Suspected Area | See |
|---|---|---|
| Remote Up / Down Function does not Operate | Proceed to "Remote Up / Down Function does not Operate" | Refer to Remote Up / Down Function does not Operate |
| LIN communication system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING | |
| Multiplex network master switch assembly | Refer to TERMINALS OF ECU | |
| Front power window regulator motor assembly RH | Refer to INSPECTION | |
| Rear power window regulator motor assembly LH | Refer to INSPECTION | |
| Rear power window regulator motor assembly RH | Refer to INSPECTION | |
| Driver Side Power Window does not Operate with Multiplex Network Master Switch | Proceed to "Driver Side Power Window does not Operate with Power Window Master Switch" | Refer to Driver Side Power Window does not Operate with Power Window Master Switch |
| LIN communication system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING | |
| Front power window regulator motor assembly LH | Refer to INSPECTION | |
| Multiplex network master switch assembly | Refer to TERMINALS OF ECU | |
| Main body ECU | Refer to TERMINALS OF ECU | |
| Wire harness or connector | - | |
| Front Passenger Side Power Window does not Operate with Front Passenger Side Power Window Switch | Proceed to "Front Passenger Side Power Window does not Operate with Front Passenger Side Power Window Switch" | Refer to Front Passenger Side Power Window does not Operate with Front Passenger Side Power Window Switch |
| LIN communication system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING | |
| Front power window regulator motor assembly RH | Refer to INSPECTION | |
| Front power window regulator switch assembly RH | Refer to INSPECTION | |
| Main body ECU | Refer to TERMINALS OF ECU | |
| Wire harness or connector | - | |
| Rear Power Window LH does not Operate with Rear Power Window Switch LH | Proceed to "Rear Power Window LH does not Operate with Rear Power Window Switch LH" | Refer to Rear Power Window LH does not Operate with Rear Power Window Switch LH |
| LIN communication system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING | |
| Rear power window regulator motor assembly LH | Refer to INSPECTION | |
| Rear power window regulator switch assembly LH | Refer to INSPECTION | |
| Main body ECU | Refer to TERMINALS OF ECU | |
| Wire harness or connector | - | |
| Rear Power Window RH does not Operate with Rear Power Window Switch RH | Proceed to "Rear Power Window RH does not Operate with Rear Power Window Switch RH" | Refer to Rear Power Window RH does not Operate with Rear Power Window Switch RH |
| LIN communication system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING | |
| Rear power window regulator motor assembly RH | Refer to INSPECTION | |
| Rear power window regulator switch assembly RH | Refer to INSPECTION | |
| Main body ECU | Refer to TERMINALS OF ECU | |
| Wire harness or connector | - | |
| Driver Side Power Window Auto Up / Down Function does not Operate with Multiplex Network Master Switch | Proceed to "Driver Side Power Window Auto Up / Down Function does not Operate with Power Window Master Switch" | Refer to Driver Side Power Window Auto Up / Down Function does not Operate with Power Window Master Switch |
| LIN communication system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING | |
| Front power window regulator motor assembly LH | Refer to INSPECTION | |
| Multiplex network master switch assembly | Refer to TERMINALS OF ECU | |
| Glass position initialization | Refer to INITIALIZATION | |
| Wire harness or connector | - | |
| Front Passenger Side Power Window Auto Up / Down Function does not Operate with Front Passenger Side Power Window Switch | Proceed to "Front Passenger Side Power Window Auto Up / Down Function does not Operate with Front Passenger Side Power Window Switch" | Refer to Front Passenger Side Power Window Auto Up / Down Function does not Operate with Front Passenger Side Power Window Switch |
| Front power window regulator motor assembly RH | Refer to INSPECTION | |
| Front power window regulator switch assembly RH | Refer to INSPECTION | |
| Glass position initialization | Refer to INITIALIZATION | |
| Wire harness or connector | - | |
| Rear Power Window LH Auto Up / Down Function does not Operate with Rear Power Window Switch LH | Proceed to "Rear Power Window LH Auto Up / Down Function does not Operate with Rear Power Window Switch LH" | Refer to Rear Power Window LH Auto Up / Down Function does not Operate with Rear Power Window Switch LH |
| Rear power window regulator motor assembly LH | Refer to INSPECTION | |
| Rear power window regulator switch assembly LH | Refer to INSPECTION | |
| Glass position initialization | Refer to INITIALIZATION | |
| Wire harness or connector | - | |
| Rear Power Window RH Auto Up / Down Function does not Operate with Rear Power Window Switch RH | Proceed to "Rear Power Window RH Auto Up / Down Function does not Operate with Rear Power Window Switch RH" | Refer to Rear Power Window RH Auto Up / Down Function does not Operate with Rear Power Window Switch RH |
| Rear power window regulator motor assembly RH | Refer to INSPECTION | |
| Rear power window regulator switch assembly RH | Refer to INSPECTION | |
| Glass position initialization | Refer to INITIALIZATION | |
| Wire harness or connector | - | |
| Key-off Operation Function Operates even if Operating Conditions are not Satisfied | Proceed to "Key-off Operation Function Operates even if Operating Conditions are not Satisfied" | Refer to Key-off Operation Function Operates even if Operating Conditions are not Satisfied |
| LIN communication system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING | |
| Lighting system (door courtesy switch circuit) | Refer to Door Courtesy Switch Circuit | |
| Front power window regulator motor assembly LH | Refer to INSPECTION | |
| Front power window regulator motor assembly RH | Refer to INSPECTION | |
| Rear power window regulator motor assembly LH | Refer to INSPECTION | |
| Rear power window regulator motor assembly RH | Refer to INSPECTION | |
| Main body ECU | Refer to TERMINALS OF ECU | |
| Auto Up Operation does not Fully Close Power Window (Jam Protection Function is Activated) | Proceed to "Auto Up Operation does not Fully Close Power Window (Jam Protection Function is Activated)" | Refer to Auto Up Operation does not Fully Close Power Window (Jam Protection Function is Activated) |
| Glass position initialization (applicable location) | Refer to INITIALIZATION | |
| Improper installation (applicable location) | - | |
| Front power window regulator motor assembly LH | Refer to INSPECTION | |
| Front power window regulator motor assembly RH | Refer to INSPECTION | |
| Rear power window regulator motor assembly LH | Refer to INSPECTION | |
| Rear power window regulator motor assembly RH | Refer to INSPECTION | |
| Jam Protection Function does not Operate | Proceed to "Jam Protection Function does not Operate" | Refer to Jam Protection Function does not Operate |
| Glass position initialization (applicable location) | Refer to INITIALIZATION | |
| Front power window regulator motor assembly LH | Refer to INSPECTION | |
| Front power window regulator motor assembly RH | Refer to INSPECTION | |
| Rear power window regulator motor assembly LH | Refer to INSPECTION | |
| Rear power window regulator motor assembly RH | Refer to INSPECTION |
REAR QUARTER POWER WINDOW CONTROL SYSTEM
| Symptom | Suspected Area | See |
|---|---|---|
| Rear Quarter Window does not Operate with Power Quarter Window Switch | Proceed to "Power Vent Window Motor Circuit" | Refer to Power Vent Window Motor Circuit |
| Power vent window motor assembly LH | - | |
| Power vent window motor assembly RH | - | |
| Power quarter window switch | - | |
| Wire harness or connector | - | |
| Main body ECU | Refer to TERMINALS OF ECU |
Factory Service Tools
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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.
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