Acura MDX start-stop problems

Filed Nov 2, 2026 · Engine · IN

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 the federal safety agency 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.

Filed Oct 27, 2026 · Engine · 90,000 miles · FL

The contact owns a 2019 Acura MDX. The contact stated that while operating the vehicle, the engine failed to restart after the Auto START/STOP was engaged. The contact stated that while at a stop light, the engine failed to automatically restart after releasing the brake pedal. The contact shifted to park(P) and restarted the vehicle. The contact stated that the failure had occurred on several occasions. Additionally, while the contact’s wife was driving, the vehicle stalled and had to be manually restarted. The local dealer and the manufacturer were notified of the failure. The contact stated that the vehicle had experienced the failure listed in the federal safety agency Action Number: EA25004 (ENGINE AND ENGINE COOLING). The failure mileage was 90,000.

Filed Oct 26, 2026 · Electrical, Engine · 14,000 miles · TN

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 the federal safety agency 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.

Filed Oct 26, 2026 · Acceleration · NJ

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.

Filed Oct 21, 2026 · Engine · OH

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.

Filed Oct 15, 2026 · Engine · 70,357 miles · CA

The contact owns a 2020 Acura MDX. The contact stated that the vehicle was previously repaired under Technical Service Bulletins: 22-009, 22-024, and 23-002; however, the failure persisted following the repairs. The contact stated that while stopped at an intersection, the engine failed to restart after the Auto Start/Stop feature engaged, and the transmission independently shifted to Neutral (N). The contact shifted the transmission to Park (P) and pressed the Engine Start/Stop button to restart the vehicle. The vehicle was taken to the dealer, where it was determined that the starter required replacement. The dealer requested that the manufacturer replace the starter; however, the request was denied. The contact associated the failure with the federal safety agency Action Number: EA25004 (Engine and Engine Cooling). The failure mileage was 70,357.

Filed Oct 14, 2026 · Engine · TX

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 the federal safety agency 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)

Filed Oct 13, 2026 · Electrical · PA

Faulty and auto-stop/start system glitch where the engine fails to turn back on. This issue frequently occurs while driving in traffic or at a stop light. This issue happens daily become extremely dangerous as car unexpected turns off and fails to turn back on a busy road. There is no option to turn off the auto-stop/start system to avoid the glitch.

Filed Sep 17, 2026 · Engine, Fuel system · PA

issue occurring with automatic start/stop function. car stalls on occasion trying to restart, goes into neutral, even though battery is new and in good condition. hard to replicate and occurs randomly. car has to be turned off and on again. this is the 4th time this has happened over the course of 3 years. seems to be happening to others based on forums as well.

Filed Sep 16, 2026 · Electrical, Engine · TX

I own a 2025 Acura MDX A-Spec purchased in XXX from John Eagle Acura in [XXX]. The vehicle has less than 10,000 miles. Component/system: The Auto Idle Stop/start system has malfunctioned. During the past week, the engine unexpectedly shut off while stopped at red lights and stop signs approximately 4–5 times. When it was supposed to restart, the vehicle sometimes failed to restart normally and required multiple attempts. The vehicle and components are available for inspection upon request. Safety risk: These incidents occurred at intersections while I was stopped in traffic. When the engine failed to restart, I was unable to immediately proceed while vehicles were behind me, creating a potential collision and traffic hazard. I regularly have my two young children in the vehicle, making this especially concerning. Dealer inspection: I brought the vehicle to John Eagle Acura after experiencing the problem. The service advisor indicated that this is a known issue, and the vehicle was serviced for the concern. The failure occurred repeatedly in real-world driving, but I do not know whether the dealer was able to reproduce it during inspection. Manufacturer/other inspection: The vehicle was inspected by an authorized Acura dealership. It has not been inspected by police or insurance representatives. Warnings/symptoms: I received no prior notification or warning from Acura regarding this issue. The first incidents occurred during the week before my dealership visit. The engine shut off while stopped and then did not restart normally. I did not observe a warning lamp or message specifically indicating that the vehicle would fail to restart. After experiencing the problem, I learned that the federal safety agency has an ongoing investigation, EA25-004, involving Auto Idle Stop failures on Honda and Acura vehicles, including 2023–2025 Acura MDX models. I am submitting this complaint so these repeated incidents can be documented as part of the federal safety agency's review. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 5