Tl* the contact owns a 2006 Toyota sienna. The contact received notification of NHTSA campaign numbers: 17v657000 (power train) and 14v273000 (tires) however, the parts needed for the repair were not available. The contact stated that the manufacturer exceeded a reasonable amount of time for the recall repair. The contact called the rockingham Toyota of broadway dealer at (603) 893-3526 located…
2006 Toyota Sienna powertrain problems
severe 35 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Failure mileage
Complaints
35
Recalls
0
Avg fix
$2,500
4crashes
3injuries
What stands out
Owners have filed 35 powertrain complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
Among the 16 model years of Toyota Sienna in our records for powertrain problems, this one ranks #3 by owner-complaint volume.
The failure pattern owners describe
Buyer takeaway: The 2006 Sienna's powertrain exhibits chronic issues spanning transmission hesitation, unexpected acceleration on shifting, and loss of gear engagement—some creating serious safety risks. Before buying, have a pre-purchase transmission inspection including full test drive through low-speed gear transitions; verify shifter and shift-lock function; and ask the seller about any transmission work or hesitation history.
Owners describe a powertrain that behaves unpredictably, starting from early use. Transmission hesitation at low speeds (5-10 MPH) during acceleration from stops is the most consistent complaint—the vehicle lurches forward harshly once it finally engages, creating rear-end collision risk. Some report the transmission drops into Neutral as they slow, then hesitates on re-engagement; dealers acknowledge this but claim it's intentional and that other Toyota models received a computer patch the Sienna never got.
More dangerous: several owners report unintended acceleration when shifting into Drive, reaching 60 MPH without touching the throttle. Two separate car-wash incidents occurred. Owners emphasize no floor mats were present and they know where the brake is, pushing back on Toyota's skepticism.
Transmission failure at highway speed has sent vehicles coasting to a halt with no forward gears available. One owner lost power at 65 MPH on Interstate 90; a radiator inlet pipe had corroded, draining transmission coolant and causing the fluid to burn. Owners report the check engine light never came on despite dangerously high coolant temps, and no diagnostic codes were stored—they question why.
Shift-lock and shifter problems plague the fleet: the shift lever moves freely out of Park when the ignition is off in some vehicles. Vehicles parked on level driveways have rolled forward without any gear being selected. One driver was pinned against her garage door. A recall (17V657000) was issued for 2004-2005 and 2007-2009 models, leaving 2006 in a gap; parts became unavailable at dealers anyway.
Gear-specific issues include transmission stuck in 2nd or 3rd gear for extended periods, and shifter bushings breaking so the lever disconnects from the cable, trapping the vehicle in reverse. Traction control randomly engages on dry, straight pavement without storing error codes.
Same Toyota Sienna powertrain reports on nearby years: 2005 · 2007 · 2008
Failure modes owners describe
Unintended acceleration on shifting into Drive
Vehicle accelerates to high speed (reaching 60 MPH in one case) immediately upon shifting from Neutral into Drive without driver depressing accelerator pedal. Occurs when leaving car wash or in normal driving conditions. Brakes reported as ineffective. Drivers report no floor mats present and clear knowledge of brake location.
When: At the moment of shifting into Drive from Neutral
Symptoms owners cite: Vehicle accelerates to 60 MPH without accelerator input; Brake pedal appears ineffective; Occurs during routine gear shifting at low speeds
Repairs/costs cited: Vehicle inspected by Toyota; deemed in perfect mechanical condition. Toyota claimed not responsible.
Transmission hesitation and surging during acceleration and deceleration
Vehicle hesitates when accelerating from stops or low speeds (5-10 MPH), surges unexpectedly, or jerks into gear. Transmission struggles to decide which gear to engage. Affects driver safety when pulling into traffic. Dealers attribute to normal function or drive-by-wire system design but offer no correction.
When: Primarily at low speeds (5-10 MPH) and when accelerating from stops
Symptoms owners cite: Hesitation during acceleration from stops; Surging forward unexpectedly; Vehicle jerks or lurches into gear; Transmission takes time deciding which gear to engage; Vibration at higher speeds; Slow shift from 1st to 2nd gear
Repairs/costs cited: AAMCO replaced valve body, torque converter, transmission cooling system. After repair, transmission remained sluggish with slow gear changes. One dealer reprogrammed ECM; problem recurred after 2 weeks.
Recalls/TSBs owners mention: Toyota dealer claimed ECM warranty (8 yr/80k miles) covers only manufacturing defects, not ECM misbehavior. No TSBs available for 2004-2006 Siennas regarding this issue.
Transmission slipping and dropping into Neutral at stops
Transmission drops into Neutral as vehicle slows for stops, then hesitates to re-engage when accelerating. Leaves driver vulnerable to rear-end collisions and causes harsh lurching when transmission finally engages. Reported from vehicle's earliest use.
When: As vehicle decelerates approaching stops; reprises during acceleration after stop
Symptoms owners cite: Transmission drops into Neutral during deceleration; Hesitation/delay before re-engaging on acceleration; Vehicle lurches harshly into gear; Risk of rear-end collision due to hesitation
Repairs/costs cited: Service technician acknowledged problem and stated other Toyota models received a 'computer patch' that fixed the issue, but no such patch available for Sienna.
Recalls/TSBs owners mention: Toyota acknowledged problem exists on other models; computer patch available for those but not for Sienna.
Transmission failure at highway speed
Engine races, transmission loses forward gears, and vehicle coasts to halt while traveling at traffic speed on highway. No gear produces movement forward, though Reverse works. Transmission fluid darker than normal. Forward sprag failure documented in one case. Transmission replaced under powertrain warranty.
When: While traveling at highway cruise speed
Symptoms owners cite: Engine races; Loss of forward gears; Vehicle drifts to halt; Vehicle cannot be shifted to produce forward motion; Reverse gear still functional; Transmission fluid darker than normal
Repairs/costs cited: Transmission replaced under powertrain warranty. Failure attributed to forward sprag failure.
Recalls/TSBs owners mention: Transmission replaced under powertrain warranty.
Transmission oil leak and overheating from radiator/coolant line failure
Radiator inlet pipe fails or corrodes, causing transmission oil to leak out. Transmission oil overheats due to loss of coolant flow. High coolant temperatures spike without triggering check engine light. Transmission fluid smells burnt. Owner questions why no diagnostic codes stored.
When: At higher mileage (133,279 miles reported) without prior warning
Symptoms owners cite: Slow response to gear shifting; Difficulty moving into gear; Unable to start or move after stopping; Transmission fluid burnt smell; No check engine light despite high coolant temp; No DTC codes stored in OBDII
Repairs/costs cited: Radiator replaced at $1,150.26. Transmission declared bad; replacement quoted at $3,780. After repair, transmission difficult to engage.
Transmission bearing noise and deterioration
Whirring/grinding noise develops at low speeds (25-45 MPH), most apparent when lifting foot off gas. Diagnosed as side carrier bearing inside differential failing. Occurs at relatively low mileage in careful driver. Indicates transmission design flaw.
When: At 76,000 miles; noise between 25-45 MPH
Symptoms owners cite: Whirring sound like turbo whine; Grinding noise between 25-45 MPH; Noise most apparent when lifting foot off gas (no load)
Repairs/costs cited: Transmission replacement quoted at $5,700.
Stuck-in-gear or inability to shift gears
Transmission gets stuck in particular gears (commonly 2nd or 3rd), runs extended periods in one gear, then clunks harshly into next. Intermittent nature makes dealer diagnosis difficult; dealers claim unable to duplicate and refuse repair. Also includes shifter cable failure and shifter lever becoming inoperable.
When: Intermittent; one case reported from 1 month after purchase
Symptoms owners cite: Transmission stuck in 2nd or 3rd gear for extended times; Hard clunk when finally shifting to next gear; Hesitation; vehicle won't accelerate into next gear; Shifter lever becomes inoperable; Shifter cable failure
Repairs/costs cited: Multiple dealer visits yielded no repairs because problem could not be reproduced in shop. Shifter cable replaced once but failure recurred.
Recalls/TSBs owners mention: Dealers refuse to repair, claiming inability to duplicate issue.
Shift lock solenoid failure and gear shift lever dysfunction
Shift lever can be moved out of Park when ignition is off and brake pedal not depressed. Occurs 50% of the time and is reproducible. Creates danger for children to inadvertently shift vehicle. Also includes inability to shift out of Park unless brake pedal depressed, or shift lever stuck entirely.
When: Intermittent; can happen multiple times daily
Symptoms owners cite: Shift lever moves out of Park with key out and brake not pressed; Shift lever free and loose in Park; Inability to shift out of Park without brake pedal; Gear shift lever stuck; vehicle won't run
Repairs/costs cited: One case involved towing with stuck shifter.
Recalls/TSBs owners mention: Recall 17V657000 (POWERTRAIN) issued for 2004-2005 and 2007-2009 models, but 2006 model falls into gap. Parts for recall repair became unavailable at dealers.
Vehicle rolling out of Park unintentionally
Vehicle rolls forward (or forward and backward) when parked on level ground and in driveway, even with engine running. No gear was manually selected; vehicle begins moving on its own. One case resulted in vehicle pinning driver against garage door.
When: While vehicle parked; occurs during engine shutdown or immediately after parking
Symptoms owners cite: Vehicle rolls forward from Park; Vehicle rolls both forward and backward from Park; Rolling occurs without manual gear selection; Vehicle continues rolling despite Park being selected
Repairs/costs cited: One case pinned driver between garage door and vehicle hood, causing injury. Dealers unable to find failures in some cases.
Recalls/TSBs owners mention: Recall 17V657000 (POWERTRAIN) performed in one case, but failure persisted. Toyota claimed vehicle can be driven despite safety risk.
Ignition key falls out or won't turn off
Key falls out of ignition when parked and vehicle shut off. No warning lights illuminate. Prevents driver from confirming vehicle is properly off.
When: Upon attempting to turn off vehicle after driving
Symptoms owners cite: Ignition key falls out; Key won't stay in ignition; No warning indicators
Recalls/TSBs owners mention: Manufacturer made aware but provided no assistance.
Gear shift bushing broken; shifter cable disconnection
Bushing for gear shift breaks, causing lever to disconnect from cord. Vehicle becomes stuck in reverse gear with no ability to shift. Multiple YouTube videos document this as known issue.
When: Vehicle can become stuck without warning
Symptoms owners cite: Shifter lever disconnects from cable; Vehicle stuck in reverse; Nearly caused collision when unable to shift to Drive
Repairs/costs cited: Known issue documented on YouTube by multiple users.
Traction control false engagement
Traction control system randomly engages on dry pavement while driving straight at speeds as low as 35 MPH and up to 65 MPH on highway. Causes sudden braking and steering pull for 1-2 seconds. No error code generated. Traction control light continues blinking.
When: Random engagement during normal driving on dry, straight pavement
Symptoms owners cite: Traction control engages without cause; Sudden braking applied; Steering pulled to one side; Traction control light blinks; No error code stored
Synthesized from 35 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 1 most recent
Had powertrain trouble with your 2006 Toyota Sienna?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2006 Toyota Sienna?
It's a meaningful issue. 35 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $2,500.
At what mileage does the powertrain typically fail?
Across the 21 complaints that reported odometer mileage, most powertrain failures cluster between 45,000 and 161,000 miles, with the median around 75,800. A quarter of owners report trouble before 45,000; a quarter make it past 161,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2006/Toyota/Sienna.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.