Every 2025 Sienna has the radar-based Advanced Rear Seat Reminder: it can warn at shutdown, again after locking, and activate the horn 90 seconds later if a rear occupant is still detected.
Check that your vehicle has it.
Toyota states that the radar-based Advanced Rear Seat Reminder is standard on every 2025 Sienna grade.
- Retail trim / version
- LE, XLE, XSE, Woodland Edition, Limited, Platinum, All 2025 Sienna grades
- Required equipment / service
- Standard radar-based Advanced Rear Seat Reminder
Does the documented scope match your car?
This check combines the verified year, any source-supported powertrain scope, source-named trim/package and required equipment. It does not read a VIN or factory build record.
Published availability and qualifications
Toyota states that the radar-based Advanced Rear Seat Reminder is standard on every 2025 Sienna grade.
Know what kind of control to look for.
This original category diagram is an orientation aid, not a picture of your exact trim. Use the written labels and your vehicle manual to identify the real control.
Step by step.
- 01
Leave Rear Seat Reminder enabled in vehicle settings and treat it as a backup, not a substitute for checking the cabin.
- 02
After a rear door was used, turn the power switch off and read the approximately six-second pre-warning on the multi-information display.
- 03
Physically inspect the second row, third row and footwells before exiting and locking the vehicle.
- 04
If the buzzer, flashers and post-lock message activate, unlock immediately and check every rear seating area.
- 05
If the horn escalation begins after the initial warning, respond immediately; it can continue for up to 20 minutes or until the rear passenger exits.
Important limits
- The system may miss an occupant or warn unnecessarily; always perform a physical rear-seat check.
- Metal objects, radio-wave shielding, 60 GHz devices, body position and coverings with heat-reflecting material can affect detection.
- Pressing and holding OK can temporarily silence the presented warning, but should be done only after confirming the rear is safe.
Quick checks.
- ✓If Rear seat reminder unavailable appears, remove metal or radio-shielding objects near the passenger and eliminate nearby interference where possible.
- ✓If a false warning occurs, check for moving cargo, open windows, vibration or strong wind before disabling the function.
- ✓If the unavailable message persists after clearing the cabin, have Toyota inspect the sensors.
What happened on your vehicle?
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2025 Toyota Sienna Owner's Manual — Advanced Rear Seat Reminder
Relevant section or page: Pages 173–175. We use the written official source to determine the steps and applicability shown above.
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Reviewed with a visible trail.
Scope and steps were checked by Car Cheat Codes Editorial Review. A guide is narrowed or corrected when the source does not support a broader claim.
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- Last modified
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Guide change history
- Initial verified publication.