Flash reprogramming allows the Electronic Control Unit (ECU) software to be updated without replacing the ECU. Flash calibration updates for specific vehicle models/ECUs are released as field-fix procedures described in individual Service Bulletins. This bulletin details the Global Techstream+ (GTS+) ECU flash reprogramming procedures and outlines use of the Technical Information System (TIS) and the Calibration Update Wizard+ (CUW+). To ensure the correct ECU software is installed, ECUs will require a Security Signature before the ECU will initialize the flash reprogramming sequence. This bulletin also details the process for acquiring a Security Signature from TIS during the GTS+ ECU flash
full bulletin at NHTSA ↗2025 Toyota Grand Highlander engine problems
moderate Owners of the 2025 Toyota Grand Highlander have filed 8 NHTSA complaints about the engine at roughly $3,100 to repair (U.S. federal records, as of October 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
Complaints
8
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2024 Grand Highlander | 10 |
| 2025 Grand Highlander (this page) | 8 |
When does it fail?
Of the 8 engine complaints filed for the 2025 Toyota Grand 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
Owners are still filing on this — the most recent NHTSA engine complaint for this vehicle was logged 21 days ago.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine 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.
Flash reprogramming allows the Electronic Control Unit (ECU) software to be updated without replacing the ECU. Flash calibration updates for specific vehicle models/ECUs are released as field-fix procedures described in individual Service Bulletins. This bulletin details the Global Techstream+ (GTS+) ECU flash reprogramming procedures and outlines use of the Technical Information System (TIS) and the Calibration Update Wizard+ (CUW+). To ensure the correct ECU software is installed, ECUs will require a Security Signature before the ECU will initialize the flash reprogramming sequence. This bulletin also details the process for acquiring a Security Signature from TIS during the GTS+ ECU flash
full bulletin at NHTSA ↗This is to advise of various price adjustments that will affect Toyota Genuine Motor Oil and Long Life Coolant, effective March 1, 2024. These products are ordered through the Toyota Complete Maintenance Care (TCMC) website.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 4 most recent
Engine temperature overheated during long idle on an out of town event. The vehicle put in park and engine running in idle with AC running. Vehicle coolant temp reach high mark in the red area. Vehicle temp alarm gave a warning to shutdown. I estimated the car idle time 40 min due to traffic accident ahead. The incident occurred on 9/11/26. The car was taken to dealer 9/17/26 for…
The contact owned a 2025 Toyota Grand Highlander. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed with radiator failure. The contact was informed that there was a hole in the radiator. The contact was informed that the radiator needed to be replaced. The vehicle was repaired. The…
A piece of road debris/rock struck the radiator/heat exchangers in my 2025 Toyota Grand Highlander Hybrid that immediately damaged the radiator/heat exchangers to result in coolant leakage and sudden loss of propulsion and terminated the engine from moving and required a tow to a Toyota dealer and thus a replacement of the heat exchanger/radiator. It came apparent from their experience that…
The contact owns a 2025 Toyota Grand Highlander. The contact stated that while driving 70 MPH, the air conditioner failed to operate. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed and determined that the condenser had failed and needed to be replaced. The dealer informed the contact that the front grille had large open apertures and no…
Had engine trouble with your 2025 Toyota Grand 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 engine problem on the 2025 Toyota Grand Highlander?
It's a documented issue but not catastrophic. 8 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Based on the 8 complaints filed, engine issues most often appear around 14,917 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine 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 engine?
No active recalls currently cover engine 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/2025/Toyota/Grand 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.