TSB: REVISION NOTICE July 01, 2019 Rev2: ? Applicability has been updated to 2019 ? 2020 model year Toyota vehicles. ? The Techstream Preparation and Process Overview sections have been updated. October 30, 2017 Rev1: ? Applicability has been updated to include 2018 model year vehicles. Any previous printed versions of this bulletin should be discarded. SUPERSESSION NOTICE The information contained in this bulletin supersedes SB No. T-SB-0012-13. Service Bulletin No. T-SB-0012-13 is obsolete and any printed versions should be discarded. Be sure to review the entire content of this bulletin before proceeding. Flash reprogramming allows the Electronic Control Unit (ECU) software to be updated
full bulletin at NHTSA ↗2006 Toyota Highlander powertrain problems
severe 19 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Failure mileage
Complaints
19
Recalls
0
Avg fix
$2,500
1crash
2injuries
When does it fail?
Of the 19 powertrain complaints filed for the 2006 Toyota Highlander, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
No new NHTSA powertrain complaint has been filed on this vehicle in over 5 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
TechTip: Condition - The vehicle may be difficult to start or have an abnormally low or rough idle after the battery has been disconnected or power to the Engine ECM has been interrupted.
full bulletin at NHTSA ↗TechTip: Condition: Engine No Start and/or Poor Engine Power DTCs set immediately after performing service on the Inverter such as SSC D0M for IPM replacement or Inverter Assembly Installation.
full bulletin at NHTSA ↗TSB: World Standard (WS) Automatic Transmission Fluid (ATF) was introduced to reduce maintenance costs and increase the mileage between scheduled maintenance checks. Here are some important tips when working with ATF-WS in Toyota vehicles requiring it's use.
full bulletin at NHTSA ↗TSB: The purpose of this bulletin is to provide precautions to follow when installing an automatic transmission/transaxle assembly to avoid MIL "ON" shifting issues and/or transmission damage. Use the information in this bulletin when installing an automatic transmission/transaxle assembly.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2006 Highlander shows a consistent pattern of transmission hesitation in the 5-speed automatic that catches owners off guard in traffic. From a full stop or slow speed, applying throttle triggers a 2–3 second delay before the transmission engages, often followed by a sudden lurch that catches drivers and passengers off guard. When easing off the throttle and reapplying it, the transmission hangs between gears before slamming into gear with force. Multiple owners report the feeling of the ignition cutting off momentarily then the engine catching—a behavior dealers attribute to electronic throttle control or "fly-by-wire" design, claiming it's intentional for fuel economy and that all Highlanders operate this way. Attempted ECU reprogramming at dealers sometimes made it worse. One owner's transmission was replaced at 9,500 miles but exhibited similar behavior afterward.
More serious failures include complete brake pressure loss (codes C1256, C1391) with the pedal sinking to the floor and a whistling sound, and involuntary forward/backward lurching when placing the vehicle in gear despite brake application. A hybrid model had its 4WD system cut power to all wheels during tire slip rather than engage 4WD. One owner faced a $4,259.81 transfer case replacement that a known TSB (TC008-07) might have prevented. No recall or acknowledged defect from Toyota; service departments consistently denied the problems were anything other than normal operation.
Same Toyota Highlander powertrain reports on nearby years: 2005 · 2008
Failure modes owners describe
Transmission hesitation and delayed shift response
The 5-speed automatic transmission exhibits 2–3 second delays when accelerating from stops or slow speeds, and erratic behavior when letting off the throttle then reapplying it. The transmission hangs between gears before lurching or slamming into gear, causing unpredictable acceleration and jerking. Owners report the vehicle feels like the ignition cuts off momentarily before catching again. This occurs across varied driving scenarios including highway merges, stop-and-go traffic, and parking lot exits.
When: 2006 model year; reported from new through 35,550 miles; onset observed within first few months of ownership
Symptoms owners cite: 2–3 second hesitation upon rapid acceleration; Transmission stays between gears and hesitates before shifting; Transmission lunges or slams into gear suddenly; Vehicle jerks or lurches forward after delay; Unpredictable acceleration response; Erratic downshifting even during uphill throttle application; Transmission 'gear hunting' on flat and uphill roads; Hard braking required after transmission finally engages
Repairs/costs cited: Dealers attempted ECU/chip reprogramming; Toyota replaced one transmission at 9,500 miles but replacement exhibited similar (though less severe) behavior. No successful repair documented in narratives.
Recalls/TSBs owners mention: Toyota and dealers claim this is inherent electronic throttle or 'fly-by-wire' design; dealers told customers the issue is how all Highlanders operate or attributed it to ECU learning driving habits. No recall; no Technical Service Bulletin (TSB) addressing this behavior documented in complaints. Dealers refused to acknowledge defect.
Complete brake system failure (loss of brake pressure)
Brake pedal suddenly sank to the floor with complete loss of stopping power. Multiple dashboard warning lights illuminated. OBD codes C1256 (accumulator low pressure) and C1391 (abnormal leak of accumulator pressure) recorded. Brakes momentarily returned after stopping but failed again within 2–3 minutes with loud, high-pitched whistle indicating accumulated pressure loss. Vehicle had to be towed.
When: During normal driving
Symptoms owners cite: Brake pedal goes to floor with no resistance; Complete loss of braking power; Multiple dashboard warning lights; Loud, high-pitched whistle sound from brake system; Brake failure recurs within 2–3 minutes after stopping
Repairs/costs cited: Vehicle required 200-mile tow; narratives do not specify repair performed
Involuntary vehicle movement despite brake application
After starting the engine and placing the car in gear, the vehicle involuntarily and immediately jumps forward or backward and continues to move even when the brakes are fully applied. The brake pedal has no effect on stopping the movement. Driver must rapidly pump the brakes repeatedly to bring the vehicle to a stop. This occurs every time the vehicle is placed into gear after engine start.
When: Occurs every time vehicle is placed in gear after engine start
Symptoms owners cite: Vehicle involuntarily moves forward or backward immediately upon gear engagement; Brakes have no effect on stopping the movement; Continuous motion despite brake application; Rapid brake pumping required to stop vehicle
Front differential failure
Front differential failed, producing roaring noise from front end at highway speeds and humming noise above 40 mph. Dealer diagnostic confirmed bad front differential with repair estimate of $4,500.
When: During highway driving
Symptoms owners cite: Roaring noise from front end at highway speeds; Humming noise heard above 40 mph
Repairs/costs cited: Front differential replacement estimated at $4,500
Transfer case seal failure
Transfer case bearing seal failed, causing vehicle breakdown on highway. Owner charged $4,259.81 for replacement. Toyota had issued TSB TC008-07 recommending right-hand bearing seal replacement that would have prevented failure, but dealership did not perform this maintenance despite multiple service visits while vehicle was under warranty.
When: Highway driving; vehicle was in service multiple times under warranty before failure
Symptoms owners cite: Vehicle stopped functioning on highway
Repairs/costs cited: $4,259.81 charged for transfer case replacement
Recalls/TSBs owners mention: Toyota issued TSB TC008-07 for right-hand bearing seal replacement (preventive maintenance not performed by dealer)
Hybrid system power loss (all-wheel-drive disconnect)
On the 2006 Highlander Hybrid with 4WD 'i' system, whenever the vehicle senses even minor tire slipping, it cuts power to all wheels completely rather than engaging 4WD. Vehicle becomes completely immobilized in manageable snow and off-road conditions. Toyota confirmed this is intentional design to prevent damage to hybrid system but did not disclose this behavior in purchase literature or owner manual. Toyota acknowledged receiving other complaints but refuses to correct or inform buyers.
When: Whenever vehicle senses tire slipping, even in manageable snow/off-road conditions
Symptoms owners cite: Complete power loss to all wheels when tire slip detected; Vehicle becomes immobilized in snow and light off-road conditions; No 4WD assistance provided; instead all power cut
Recalls/TSBs owners mention: Toyota stated this is designed intentional behavior to protect hybrid system; acknowledged other complaints but refuses correction or disclosure
Random acceleration surges
Vehicle experiences random sudden acceleration surges 2–3 times per year after slowing down and slowly reapplying throttle. Surge can be mitigated by reducing throttle pressure or braking. Owners attribute this to electronic throttle control rather than driver input.
When: Random, 2–3 times per year; ongoing since vehicle purchase
Symptoms owners cite: Sudden, unpredictable acceleration thrust; Occurs after slow acceleration from reduced speed; Can be lessened by reducing throttle or braking
Recalls/TSBs owners mention: No recall; service referred owner to Toyota headquarters complaint filing
Dashboard light illumination and vehicle shutdown
All dashboard lights illuminated while driving, vehicle lost power, and engine died. Vehicle required towing. No specific diagnostic codes or repair details provided in narrative.
When: During normal driving
Symptoms owners cite: All dashboard lights illuminated simultaneously; Complete loss of power; Engine shutdown while driving
Repairs/costs cited: Vehicle towed; no repair details provided
Brake actuator failure
Power brakes stopped working due to bad brake actuator. Powertrain system also shut down while driving.
When: While driving
Symptoms owners cite: Power brakes lost functionality; Powertrain system shutdown
Synthesized from 19 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
While driving my vehicle all the lights on my dashboard illuminated. My vehicle lost power and I had to pull over. It died there. I was on belfield ave and gratz street in philadelphia, pa . I subsequently had it towedback to my residence.
I purchased a Toyota highlander sport 4 months ago. I bought the v6 engine. I became concerned about a hesitation problem where the car holds back when starting from a stop and then lurches. This is dangerous at stop lights and entering freeways. The Toyota dealer says the car does this on purpose but they don't know why. This sounds like an excise for a flaw in the design. I checked…
Had powertrain trouble with your 2006 Toyota Highlander?
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 Highlander?
It's a meaningful issue. 19 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 9 complaints that reported odometer mileage, most powertrain failures cluster between 5,407 and 67,152 miles, with the median around 35,000. A quarter of owners report trouble before 5,407; a quarter make it past 67,152. 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/Highlander.
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.