2025 Acura MDX

On June 3, 2022, the Office of Defects Investigation (ODI) opened Preliminary Evaluation PE22005 after the agency received VOQs and several field reports concerning the Auto Idle Stop (AIS) feature on 2016-2019MY Honda Pilot vehicles. The complaints allege that the engine fails to restart on its own from a complete stop at a traffic light or road intersection with the AIS function engaged. The subject vehicles are equipped with a 3.5L engine with a 9-speed automatic transmission. On January 6, 2023, Honda released service bulletins 23-008 and 23-009. These service bulletins address the failure to restart issue in the 2016-2019MY Honda Pilot vehicles, as well as the 2015-2020 Acura TLX, 2016-2020 Acura MDX, 2019-2022 Honda Passport, and 2020-2023 Honda Ridgeline vehicles. The repair outlined in the service bulletins is a two-stage countermeasure to remedy the issue. The first stage is a Programmed Fuel Injection (“PGM-FI”) software update. The second stage is only deployed if the software update fails to remedy the issue. The second stage, depending on the model and model year, consists of replacement of the starter assembly, starter relays, and a valve adjustment. Additionally, Honda extended the warranty coverage to 10 years with unlimited mileage for vehicles requiring the second stage component replacement. ODI continues to receive complaints of the AIS failure to restart, with many complainants alleging the campaign countermeasures had been completed.NHTSA has reviewed Honda's Information Request Letter responses involving warranty claims, lawsuits, and consumer complaints in addition to ODI's own data. This Engineering Analysis is being opened to further consider the potential safety defect, including gathering additional data regarding Honda’s service campaign efficacy. ODI is additionally expanding the scope to encompass all vehicles addressed in Honda’s service bulletins 23-008 and 23-009 as well as newer model year vehicles, which are substantially similar to the vehicles covered by the service campaign. To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to NHTSA.gov.

I own a 2025 Acura MDX Advance with approximately 18,500 miles. While stopped at a traffic light, the vehicle's Auto Idle Stop feature engaged and shut off the engine as designed. However, when it was time for the vehicle to restart, the engine would not restart. The failure left me unable to move the vehicle at an intersection, creating a potentially dangerous situation and exposing me and other motorists to the risk of a traffic accident. A vehicle that automatically shuts off at a traffic light must be able to reliably restart when traffic begins moving. The dealership diagnosed the problem as a failed starter and replaced the starter on November 2, 2026. The vehicle was only approximately 18,500 miles old at the time of the failure. A starter failure at such low mileage is extremely concerning, particularly when it occurs in connection with the Auto Idle Stop system. I am concerned that this may be a broader safety issue involving the 2025 Acura MDX and its Auto Idle Stop/start system. Failure to restart at an intersection can create an immediate traffic hazard, particularly in busy intersections where the driver may be unable to move the vehicle out of the way of approaching traffic. I am requesting that NHTSA investigate this issue and determine whether there is a defect involving the Auto Idle Stop system, starter, or related electrical components in 2025 Acura MDX vehicles. A vehicle should not unexpectedly become immobilized in an intersection because its automatic restart system fails.

NHTSA ID

11775223

Incident

Oct 29, 2026

My vehicle is having on going start up issues a month after purchased. Failed to restart after the automatic idle-stop system They replaced the starter & starter rely and still never fix the issue. The battery on the vehicle passed the battery test and I feel like my safety and children safety is in danger! The vehicle is not even 2 years old. The vehicle has left me at a red light , stop sign , gas station stuck due to the vehicle not turning on/ struggling to turn on . The dash board would light up with check engine, and lock the wheel.

NHTSA ID

11774686

Incident

Feb 3, 2026

The auto-stop feature engaged after I stopped at a traffic light. When attempting to begin moving again the vehicle, it would not move upon pressing the gas peddle like it typically does. Vehicle gave alerts stating “system issue shift to park” but I could not shift out of Drive. Police had to be called as cars were flying by and I had two kids in the back. Very scary situation. Eventually while waiting for a tow I googled the issue and saw recommendation to turn off the car, open and close the door. At this point the alert said “transmission issue engage emergency brake” which I did and was then able to start the car and move it. I took the car to the dealer the next day and dealer said it was a starter issue and replaced the starter under warranty. They acknowledged this is a known issue caused by the starter not reengaging after the car stops with auto start stop feature engaged. There is no way to turn off this feature without manually pressing a button each time you start the car. It never happened before and I have had this vehicle since May 2025, and has never happened again since, although I now immediately turn off the feature everytime I remember to. It is an extremely dangerous situation to be in and leaves the driver not knowing how to move the car. Shutting the car off alone did not fix the issue, but opening and closing the door and waiting 30 seconds managed to get the car to start again. Luckily the police responded quickly and blocked traffic before someone hit me. I believe something like this should be worthy of a recall as it can leave people in a very dangerous situation.

NHTSA ID

11773863

Incident

Sep 10, 2026

The contact owns a 2025 Acura MDX. The contact stated upon coming to a complete stop at an intersection downhill, the engine turned off while the instrument panel and infotainment center remained operable. The contact was unsure if the engine Auto START/STOP system was engaged during the failure. The message "Shift to Park" was displayed. The contact attempted to shift to park(P), to turn off and restart the vehicle, but the vehicle failed to respond. The message "Transmission Error-Take to Acura Dealer" was displayed. The contact's husband arrived on the scene to assist, but the Police advised the contact that an emergency tow was required due to the potential crash. The Police requested emergency towing services, and the vehicle was towed to an impound lot. The contact associated the failure with NHTSA Action Number: EA25004 (ENGINE AND ENGINE COOLING). The selling dealer, Acura of Memphis (2611 Ridgeway Rd, Memphis, TN 38119) and the manufacturer were contacted by email. The failure mileage was approximately 14,000.

NHTSA ID

11773792

Incident

Oct 24, 2026

Mileage

14,000 mi

While driving and coming to a stop, the engine shuts down and will not restart. Error "To continue to drive, depress brake pedal and push Switch". After 10 minutes of trying to start the car it finally started.

NHTSA ID

11773609

Incident

Oct 24, 2026

On three separate occasions, 2/27/26, 9/9/26, and 9/23/26 the Idle stop/start feature was inoperable and caused the vehicle to shut down. Upon attempting to turn the vehicle back on, vehicle would not immediately start back up. Inoperable and a major safety concern since this happened at a red light that was turning green. This poses a great concern due to traffic approaching the light while green not noticing the vehicle is stopped, as the entire vehicle shuts off when this happens. There is no way to get the vehicle moving again, so if there is traffic approaching, there is no way to avoid it or get out of the way. This was inspected by the dealership on 2/27/26 and dealer replaced the starter. Then this happened again on 9/9/26 and 9/23/26 - dealer replaced starter again.

NHTSA ID

11772712

Incident

Feb 27, 2026

I have had a problem with the "Auto Idle Stop" in my 2025 Acura MDX. While at a stop light 2 different times and at a stop sign 1 time the car engine shut off as it should. Upon letting off the brake and pressing the gas the car would not go. It stayed in Park and I could not get it to go. The engine would not turn back on. I received a warning light that said "depress brake and push start". Upon doing this the car still would not start. I had to open the door, shut door, push brake and then start the car. Dealer confirmed that this has been an issue.

NHTSA ID

11771386

Incident

Sep 1, 2026

My 2025 Acura MDX A-Spec Advance (VIN [XXX]) twice failed to restart after the Auto Idle Stop system shut the engine off — on XXX (~2:00 PM CDT) and again on October 10, 2026 (2:20 PM CDT). The vehicle was immobilized and would not restart. Sterling Acura of Austin ([XXX]) diagnosed a failed starter on XXX: bench testing showed 9.7 amp draw with voltage drop below 7.3V. The dealer replaced the starter motor (part 31200-5MR-A03) under warranty, test drove 10+ miles, cleared codes, and verified the repair. A no-restart after auto idle stop leaves the vehicle without motive power in traffic, which is a safety hazard. This matches the subject of NHTSA Engineering Analysis EA25004 (No Restart After Auto Start/Stop Engages, 2016–2025 MDX). INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11771218

Incident

Oct 10, 2026

Service Bulletin - Under certain circumstances, after coming to a stop and the idle stop feature engages, the vehicle may not automatically restart. In other circumstances, vehicles may experience a slow crank or fail to start under hot ambient temperature conditions.

Dealer Message - Under certain circumstances, after coming to a stop and the idle stop feature engages, the vehicle may not automatically restart. In other circumstances, vehicles may experience a slow crank or fail to start under hot ambient temperature conditions. The customer should be able to restart the vehicle by selecting Park and pushing the ENGINE START/STOP button.

Tech Line Summary Article - Customers are complaining of a clicking noise from front of vehicle while turning at low speeds. This is a temporary solution to address the issue.

Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2024-2026 MDXs with a client complaint of the Malfunction Indicator Light (MIL) on with the DTC P0441 (EVAP System Purge Flow Malfunction) stored. To better understand the cause of this condition, AHM would like to collect specific parts from the vehicle prior to you attempting a repair of any kind.

Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2024-2026 MDXs with a client complaint of the Malfunction Indicator Light (MIL) on with the DTC P0441 (EVAP System Purge Flow Malfunction) stored. To better understand the cause of this condition, AHM would like to collect specific parts from the vehicle prior to you attempting a repair of any kind.

Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2024-2026 MDXs with a client complaint of the Malfunction Indicator Light (MIL) on with the DTC P0441 (EVAP System Purge Flow Malfunction) stored. To better understand the cause of this condition, AHM would like to collect specific parts from the vehicle prior to you attempting a repair of any kind.