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 Service Bulletin No. T-SB-0012-13 is obsolete and any printed versions should be discarded.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 ↗2008 Toyota Highlander powertrain problems
severe 15 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Failure mileage
Complaints
15
Recalls
0
Avg fix
$2,500
2crashes
2injuries
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
Owners describe multiple distinct powertrain failures in the 2008 Highlander. The most dangerous: sudden acceleration while braking or parking, with vehicles lurching forward despite brake application. One owner's wife struck a building at low speed during parking, causing rib bruises and over $8,000 in repairs; another nearly crashed through a bank window. Dealers could not reproduce these events and claimed no defect existed.
Transmission engagement problems appear frequently. The transmission fails to shift into forward gears at low speeds—especially after slowing to 5 mph or during parking maneuvers—leaving the vehicle unresponsive to throttle input. Some owners report the transmission staying in first gear or coasting in neutral when attempting to shift, while others note the transmission refusing to disengage on downshifts from highway speed (55 mph), dragging the vehicle to a stop.
A recurring complaint involves the vehicle rolling forward when shifted into reverse on downward slopes, with the hill-hold feature failing in those conditions. Owners must apply brakes while pressing the accelerator to hold position—contrary to dealer claims that this is normal.
Other reported failures include transmission rattle at highway speed (60 mph, sounding like loose internal parts), complete AWD transfer box seal failure requiring $5,000+ repair and not covered by warranty, and one transmission axle failure at 4,000 miles accompanied by brake failure. One owner reported an accelerator pedal stuck at full throttle at very low mileage.
Same Toyota Highlander powertrain reports on nearby years: 2005 · 2006 · 2011
Failure modes owners describe
Sudden/unintended acceleration while braking or parking
Vehicle accelerates abruptly while owner is applying brakes, most often during low-speed parking maneuvers. Owners report the vehicle lurches forward without warning, ignoring brake input. One incident resulted in collision with a building causing injury; another nearly caused impact through a plate glass window.
When: Low-speed parking and braking maneuvers, December 2009 reported incidents
Symptoms owners cite: Unexpected acceleration while foot on brake pedal; Sudden lurch forward during parking; Vehicle continues accelerating despite brake application; Vehicle accelerates in reverse after braking during garage entry; Intermittent over-rev before automatic transmission shifts
Repairs/costs cited: One incident required over $8,000 in vehicle repairs; dealers claim no issue found during inspection
Recalls/TSBs owners mention: Dealers told owners vehicle is not on recall list; no warranty coverage offered; Toyota did not respond to written complaints
Transmission failure to engage or shift into gear
Transmission fails to engage into forward gear or remains in neutral when shifting, particularly at low speeds after slowing down or during turns. Vehicle does not respond to accelerator input. Gears may fail to disengage during downshift from highway speeds.
When: Low-speed situations after slowing to 5 mph; parking maneuvers; initial startup
Symptoms owners cite: Fails to shift into gear at low speeds; Does not respond to throttle input; Feels like clutch is disengaged in automatic; Transmission does not disengage when slowing from highway speeds; Noticeable whine between 55–62 mph; Vehicle stuck in first gear; cannot shift to other gears; Coasts in neutral when trying to shift
Repairs/costs cited: Dealer mechanic claimed whine is normal and computer-controlled; transmission slippage reported but not repaired by dealer
Vehicle rolls forward in reverse on downward slopes
When transmission is in reverse and vehicle is positioned nose-down on a slope, vehicle rolls forward instead of backing up. Hill-hold feature does not function on downward slopes. Owner must hold brake with one foot while pressing accelerator with the other to maintain position.
When: On downward slopes with transmission in reverse
Symptoms owners cite: Vehicle rolls forward when in reverse on downward slope; Hill-hold feature inoperative on slopes; Behaves like manual transmission with disengaged clutch; Occurs even on shallow inclines
Recalls/TSBs owners mention: Dealer claimed this is normal operation for the vehicle
Transmission noise and internal rattle
Owner experienced loud transmission rattle while driving on freeway at 60 mph. Noise continued for 3–4 minutes and sounded like a loose internal part. Noise stopped after shifting between gears.
When: Highway speeds around 60 mph; December 2009
Symptoms owners cite: Rattling noise from transmission; Sounds like loose part inside transmission; Noise increases in volume
AWD transfer box seal failure and fluid loss
Large oil puddle discovered beneath vehicle following routine oil change at dealer. Dealer diagnosed complete failure of AWD transfer box with no engine damage. Owner states dealer had noted possible small leak at previous oil change (63,000 miles) but provided no follow-up notification during subsequent services.
When: After oil change; prior leak noted at approximately 63,000 miles
Symptoms owners cite: Large puddle of oil (2 ft × 2 ft or larger) under vehicle; Complete failure of AWD transfer box seal; Prior small leak noted by dealer but not monitored or reported to owner
Repairs/costs cited: Estimated repair cost $5,000+; not covered by warranty
Recalls/TSBs owners mention: Dealer stated failure not covered by warranty
Transmission axle failure
While driving at 20–25 mph, transmission axle failed suddenly. Owner heard loud bang; brakes also failed at the same time. Vehicle required towing. Manufacturer was to send investigator.
When: At 4,000 miles; 20–25 mph driving speed
Symptoms owners cite: Loud bang while driving; Brakes failed simultaneously; No warning lights; Vehicle became immobile
Recalls/TSBs owners mention: Manufacturer planned to send investigator to inspect vehicle
Hybrid inverter failure (non-hybrid model)
Vehicle stopped moving mid-maneuver while engine was running. Dealer diagnosed hybrid inverter failure. Note: 2008 Highlander is not a hybrid model, suggesting possible diagnostic error or component confusion.
When: While pulling out of parking space
Symptoms owners cite: Vehicle stops moving despite running engine; Loss of drive power during low-speed maneuver
Repairs/costs cited: Diagnosed as hybrid inverter failure
Sticking accelerator pedal
Accelerator pedal became stuck at full throttle during low-mileage operation. Owner confirms issue was not related to floor mats. Problem has not recurred since initial incident.
When: Low mileage
Symptoms owners cite: Accelerator stuck at full throttle; Not floor-mat related
Synthesized from 15 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 0 most recent
Had powertrain trouble with your 2008 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 2008 Toyota Highlander?
It's a meaningful issue. 15 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 12 complaints that reported odometer mileage, most powertrain failures cluster between 5,000 and 34,000 miles, with the median around 14,000. A quarter of owners report trouble before 5,000; a quarter make it past 34,000. 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/2008/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.