Owners report that the tire pressure warning light comes on and stays on even when tire pressures are normal, or flickers on and off every 20-30 minutes while highway driving. Dealerships inspect the tires, find nothing wrong, and cannot fix the problem. One owner suggests a faulty pressure sensor; another spent $500 replacing sensors after tire changes and got no improvement. Meanwhile, tires lose air steadily — one owner was filling tires every week — despite dealership inspections finding no leaks or punctures.
The tire wear pattern is severe and consistent across premium brands. One owner went through five complete tire sets by 83,000 miles (averaging 17,000 miles per set) with cupping starting at 10,000 miles and rapid inside-wall wear. Toyota's service department acknowledged this is common in Siennas but offered no fix.
Several owners report sidewall bulges that recur every seven months even when replaced with identical tires. One owner paid out-of-pocket after the dealership classified it as a road hazard. Two owners describe tire failure at the bead, with one spare tire detaching from the frame while driving at 35 mph. The spare tire cable defect triggered recall 14V273000, but parts remained unavailable for months, leaving owners driving without a spare.
Failure modes owners describe
Tire Pressure Monitoring System (TPMS) False Warnings
TPMS warning light comes on when tire pressures are actually normal, or illuminates intermittently while driving. Dealership inspections find no tire damage. One owner suspects a faulty pressure sensor as the cause.
When: 2 months after purchase; recurring in early 2008-2009; during highway driving in 2021
Symptoms owners cite: Low tire pressure warning light comes on despite normal tire pressures; Warning light flickers on/off every 20-30 minutes while highway driving; Light remains on even after inflating all tires to normal pressure; Dealerships unable to identify or fix root cause
Repairs/costs cited: One owner was told a faulty pressure sensor could be the cause; another owner purchased a new sensor that did not resolve the issue. Dealerships declined to replace the sensor system.
Recalls/TSBs owners mention: NHTSA opened a preliminary evaluation for 2004 and 2005 Sienna tire pressure and regulating systems (referenced by owners but not confirmed for 2007).
Actual Tire Pressure Loss and Leakage
Tires lose air pressure over time, requiring frequent refilling, despite dealership inspection finding no punctures or damage. One owner alleges the TPMS sensors themselves allow air to leak.
When: Recurring from Nov 2007 through Jan 2009; ongoing for 2021 owner; generally within first 1.5 years of ownership
Symptoms owners cite: Tires go low (15-20 PSI) within weeks of filling; Owner filling tires every week; 2021 owner losing 25% air pressure in all four tires; No visible punctures or foreign objects found during dealership inspections
Repairs/costs cited: One owner had tires removed and inspected at both Toyota dealership and independent tire shop (Elliott Tire & Service); no leaks or damage found. Tire shop suggested faulty sensor. Dunlop tire company contacted with case number.
Recalls/TSBs owners mention: Toyota dealerships refused multiple requests to replace the tire sensor system.
Sidewall Bulging and Tire Failure
Bulges appear on tire sidewalls, starting at 35,000 miles and recurring repeatedly at 7-month intervals on the same vehicle. All failures involved Dunlop SP4000 tires, which were replaced with identical models.
When: First occurrence at 35,000 miles; second at ~42,000 miles (seven months later); third at ~49,000 miles (seven months after second); reported at 73,000 miles cumulative
Symptoms owners cite: Bulge or swelling along tire sidewall, pulling tire away from rim; Low tire pressure light illuminates, alerting to failure; Bulges recur on different tires even after replacement with same tire model
Repairs/costs cited: Tires replaced with exact same type (Dunlop SP4000) after each failure. One owner paid $136 out-of-pocket after dealership denied warranty claim as road hazard.
Recalls/TSBs owners mention: Dealerships classified bulges as road hazards and denied replacement coverage under warranty.
Excessive and Premature Tire Wear
Tires wear out prematurely and unevenly, requiring replacement every 17,000 miles on average at 83,000 total miles. Tires develop cupping at 10,000 miles regardless of rotation schedule. Issue occurs with multiple premium tire brands.
When: Recurring throughout ownership; by 83,000 miles, five complete tire replacements were needed
Symptoms owners cite: Tires cup at 10,000 miles; Rapid wear on inside tread wall; Requires close monitoring; Pattern consistent across Bridgestone, Michelin, and Dunlop tires
Repairs/costs cited: Owner replaced tires five times with premium brands (Bridgestone, Michelin, Dunlop) with identical failure pattern.
Recalls/TSBs owners mention: Toyota dealership and corporate stated this is a common issue with Sienna models and stated they rarely see a Sienna with more than 20,000 miles on a set of tires. No solution offered.
Tire Structural Failure - Sidewall and Bead Separation
Tires fail suddenly at the rim bead, losing the rubber seal and blowing out. One occurrence resulted in spare tire separation from vehicle frame.
When: At 1.5 years of ownership; spare tire failure at 140,000 miles
Symptoms owners cite: Tire blows out next to rim, leaving rubber around bead; Cracking visible around rim on other tires; Spare tire detaches from underneath vehicle frame without warning
Repairs/costs cited: Dealership would not warranty TPMS sensor broken during flat tire repair on 1.5-year-old vehicle; plastic sensor broke off rim.
Recalls/TSBs owners mention: Spare tire failure is related to recall NHTSA Campaign 14V273000 regarding a defective cable allowing spare to drop from frame.
TPMS Sensor Damage During Tire Changes and High Replacement Costs
TPMS sensors are damaged during routine tire changes and replacement, but Toyota provides no warning labels to mechanics. Owners are charged $134 per sensor plus labor (approximately $500 per set) for repairs that could have been prevented with a simple warning sticker.
When: During tire service; timing varies by service occasion
Symptoms owners cite: TPMS warning system fails to function after tire is changed; Owners charged unexpectedly high repair costs; No warning stickers on wheels or door to alert to sensor vulnerability
Repairs/costs cited: Toyota charges $134 per sensor plus labor; owner estimates $500 per tire change set due to sensor damage.
Recalls/TSBs owners mention: No warning system in place; owner suggests Toyota add warning stickers at wheel and door to prevent damage.
Spare Tire Retention Cable Defect and Recall Parts Delay
Spare tire cable is defective and can allow spare to drop from underneath vehicle frame. Recall campaign 14V273000 was issued, but parts were unavailable for extended periods, leaving owners without spare tires for months.
When: Identified summer of first reported year; recall notification May 2014; ongoing parts shortage through 2014
Symptoms owners cite: Spare tire detaches without warning while driving (35 mph documented); Service representative recommends removing spare due to defective cable; Recall parts unavailable at dealers; Lack of follow-up notification when parts eventually become available
Repairs/costs cited: Spare tires were removed from vehicles pending recall repair; parts unavailability prevented completion of recall work.
Recalls/TSBs owners mention: NHTSA Campaign 14V273000 issued for spare tire cable defect. Toyota/dealers unable to confirm parts availability timeframes; some owners never received follow-up notification and remain unable to complete recall repair.
Synthesized from 20 NHTSA owner complaints — unverified consumer
allegations, summarized for patterns. The verbatim filings appear below.