The 2006 Sienna has a documented pattern of tire failure unrelated to driver abuse or neglect. Owners report ply separation, sidewall rupture, and tread delamination across multiple brands—Cooper CS5, Dunlop SP4000 DSST, Goodyear Integrity, Bridgestone, Firestone, Hercules, and Douglas. Many failures occur between 8,000 and 25,000 miles despite regular rotation and maintenance at dealers.
Dunlop SP4000 DSST run-flats are especially problematic. These tires wear to bare cords in 10,000–20,000 miles on an 80,000-mile warranty, and the thick sidewalls hide pressure loss until the tire is nearly flat. The indirect tire pressure system doesn't alert drivers early; one owner drove for over a year at 22 psi instead of the recommended 35 psi before discovering the problem. When tires fail, the pressure light often doesn't activate until after blowout occurs on the highway.
Owners report violent shaking above 35 mph, banging sounds as tread separates, and sidewalls collapsing. Repair costs range from $350 to over $1,000 per set. Toyota denied warranty claims for owners outside specific VIN ranges, even when dealers identified manufacturer defects. The spare tire recall (14V273000) moved the spare to the cargo area as a temporary fix but left it unsecured for years with no permanent solution in sight.
Failure modes owners describe
Ply/Tread Separation and Sidewall Failure
Internal structural failure where tire plies or tread separate from the carcass, or sidewall bulges/ruptures develop. Owners report wire strands and steel belts exposed, fabric separation at the tread-to-sidewall junction, and outright blowouts. This occurs across multiple tire brands (Cooper CS5/CS4, Goodyear Integrity, Dunlop SP4000/DSST, Bridgestone Insignia, Hercules Roadtour, Firestone FR710, Douglas, and others).
When: Between 8,000 and 85,000 miles; many failures occur early (under 25,000 miles) despite regular rotation and maintenance. Several incidents at 10,000–21,000 miles on new or relatively new tires.
Symptoms owners cite: Violent shaking or steering wheel vibration over 35 mph; Loud banging or grinding noise from tires; Visible tread belt separation or bulging sidewalls; Wire strands protruding from tire; Sudden blowout at highway speeds without warning light activation; Uneven or abnormal tread wear (inside surface, edges, cupping)
Repairs/costs cited: Replacement tires required; costs cited range from $165–$350 per tire, often $1,000+ for a full set. Some owners paid out of pocket because tires were outside warranty or VIN range. Several complaints state manufacturers denied coverage or deferred to warranty pro-ration.
Recalls/TSBs owners mention: Toyota denied claims for some owners (e.g., complaint #1, VIN outside supplemental warranty range per complaint #9). Dunlop offered pro-ration at 48% (complaint #9). Goodyear denied refund claim (complaint #8). Some dealers cited wheel alignment or inflation pressure as cause, contradicting subsequent alignment checks showing alignment was acceptable. Multiple owners report dealerships and Toyota refused to acknowledge defect or provide assistance.
Run-Flat Tire Inadequate Pressure Detection
Dunlop SP4000 DSST run-flat and other run-flat tires on models equipped with ABS-type (indirect) tire pressure monitoring fail to alert drivers to low pressure until tires are nearly flat. The thick sidewalls designed for run-flat capability mask pressure loss visually. Owners drive extended periods on under-inflated tires, damaging sidewalls and causing eventual failure.
When: Occurring across vehicle service life; one owner ran tires at 22 psi (vs. 35 psi recommended) for over one year without dealer detecting it during maintenance.
Symptoms owners cite: Tire pressure warning light does not illuminate until tire is severely low or flat; Pressure warning light activation delayed by days or weeks after pressure loss begins; Inability to visually detect low pressure due to thick run-flat sidewalls; Repeated low pressure requiring weekly re-inflation; Sidewall collapse after prolonged under-inflation driving
Repairs/costs cited: Tire replacement required. One owner replaced all four tires at cost not specified after running on under-inflated tires for a year. Multiple owners replaced run-flats with conventional tires to regain tire pressure monitoring effectiveness.
Recalls/TSBs owners mention: Toyota acknowledged run-flat pressure system issues and issued a service bulletin in 2018, but owners report Toyota refused to retrofit standard tires or provide compensation. One dealer manager agreed the run-flat and indirect TPMS pairing was unsafe (complaint #3) but Toyota would not remedy it. Dealers told owners to ignore warning lights or attributed them to cold weather.
Premature Tire Wear (Run-Flats and Standard Tires)
Dunlop SP4000 DSST and other tires wear excessively fast despite proper maintenance, rotation, and inflation. Tread depth becomes critical (0–2/32″) well before warranty mileage (typically 80,000 mile 'wear out' warranty). Wear is often uneven across tires or within individual tires, suggesting alignment or suspension issues that dealers fail to detect or correct.
When: Premature wear observed at 10,000–30,000 miles; multiple owners report needing replacement before 25,000 miles on an 80,000 mile warranty. One owner had 4/6/5/5 to 6/8/8/7 tread depth measurements after only 40,000 miles on a set that should provide 80,000 miles.
Symptoms owners cite: Rapid tread wear becoming visible at tire rotations; Uneven wear across the four tires (some at 4/32″, others at 8/32″ on same vehicle); Edge wear and cupping evident on all tires; Zero tread depth on inside of left front tire at 14,900 miles (run-flat example); Wear pattern inconsistency not correctable by alignment alone
Repairs/costs cited: Full replacement sets costing $1,000+ (confirmed in complaints #17, #29). Warranty adjustments limited by pro-ration clause: owners often pay 50% of replacement cost if one or two tires wear out before full warranty consumption. One owner cited $558 out of pocket after Toyota paid for two of four replacement tires.
Recalls/TSBs owners mention: Toyota issued supplemental tire warranty for some production date ranges (complaint #9 references VIN-specific effectivity list), but excluded many owners by VIN. Toyota refused replacement for owners outside the warranty VIN window. Dealers claimed proper maintenance and normal wear, despite owners providing rotation records and maintenance receipts.
Loose or Missing Spare Tire Assembly (Recall Campaign 14V273000)
Recall campaign 14V273000 addressed a defective spare tire carrier mechanism that allowed the spare tire to detach from the undercarriage or come loose in the luggage compartment after the recall 'fix' (temporary relocation). The permanent solution was not designed or implemented for years, leaving tires unsecured in cargo areas where they roll, vibrate, and pose injury risk during hard braking or sharp turns.
When: Spare tire detachment or looseness reported from 2007 through 2015, coinciding with the recall's extended timeline. Recall initially issued; permanent fix delayed 6+ months with no estimated time of arrival (complaint #13).
Symptoms owners cite: Spare tire detaches and rolls onto roadway while driving; Unsecured spare tire loose in luggage compartment, rattling and moving during turns or braking; No secure mounting hardware provided in temporary recall remedy; Spare tire vibration audible and distracting to occupants
Repairs/costs cited: Recall remedy involved moving spare from undercarriage to luggage compartment (temporary) or strapping/placing it in cargo area without permanent mounting bracket. Permanent fix (new stainless steel cable and bracket mechanism) was not available for extended period. Some owners report dealers cut cables without consent as an interim measure.
Recalls/TSBs owners mention: Toyota issued recall campaign 14V273000 (2014) but delayed permanent remedy for years, citing unavailable parts. Multiple owners report Toyota refused to provide estimated repair timeline or acknowledge safety risk of unsecured tire. Some owners told by Toyota to call roadside assistance if tire was needed rather than carry a secured spare.
Tire Pressure Monitoring System (TPMS) Malfunction or Delayed Warning
Both direct and indirect TPMS fail to alert owners before tires are critically low or flat. Direct TPMS pressure sensor does not activate warning light until tire is nearly or fully flat, delaying driver response. Indirect TPMS (wheel-speed based) is insensitive to gradual pressure loss, especially on run-flat tires with thick sidewalls. After tire replacement, TPMS warning light may continue to illuminate even with proper pressure, or fail to illuminate on subsequent tire failures.
When: Failures reported throughout vehicle service life; one owner had TPMS light issues for months after new tires installed; another experienced blowout with no warning light activation (complaint #16).
Symptoms owners cite: No warning light when tire is leaking slowly or running low; Light illuminates only after tire is flat or severely compromised; Persistent warning light after new tires installed despite proper pressure in all tires; Light turns off after reset, then reappears without clear cause; Light does not illuminate during subsequent blowout event
Repairs/costs cited: Tire replacement when failures occur. TPMS sensor and valve replacement attempted in some cases (one complaint #2 mentions valve replacement, but blowout occurred 5 days later). Owners report $95 diagnostic fees at dealers with no resolution, and dealers blaming external factors (cold weather, etc.).
Recalls/TSBs owners mention: Toyota and dealers stated TPMS is functioning 'according to design' (complaints #3, #31) despite owners' safety concerns. One dealer admitted system design is unsafe but would not retrofit (complaint #3). Dealers refused to acknowledge or address systemic warning delay issue, instead advising owners to ignore lights or perform manual pressure checks.
Synthesized from 57 NHTSA owner complaints — unverified consumer
allegations, summarized for patterns. The verbatim filings appear below.