2025 Acura MDX Engine Problems

Car engine went into idle mode while the Idle Stop was engaged while stopped on an expressway off ramp. Car engine did not turn back on and entire car shut down. It took about 1 minute to re-start the car and engine. Safety was compromised because car shut off in an unsafe location. No accidents or injuries occurred. This happened about a year ago and car battery and starter were replaced by the Acura Dealer November 2025. There were no warning lights or messages prior to this problem appearing. Prior to this event, car had been slow to turn over for about 1 week. I previously submitted a complaint to NHTSA in Fall 2025, case #11694662, when this happened the first time.

NHTSA ID

11765668

Incident

Sep 19, 2026

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 NHTSA 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 NHTSA's review. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 5

NHTSA ID

11764853

Incident

Sep 16, 2026

I was driving w a passenger on a busy 4 lane road and trying to make a left turn. When I tried to hit the gas after coming to a stop, my car would not move. I did not know what was happening, as it turned out the car had shifted into park and turned off. Extremely dangerous scenario. I had to take my foot off the brake, restart the the car and put it in drive again to move. I brought it to the dealer the following day, they said they fixed it with a gear shield as the trans had dirt in it and a new starter. However, yesterday, prob about 6 or so months later it happened again. I went directly to the dealer. They kept the car over night. Today I was told the my battery charge was too low and the auto idle engine on/off turned off due to it being not having enough charge. Totally different excuse than the first time. Also, when I dropped it off I was told someone else had dropped their 2025 MDX off that same day for the same reason. I am very concerned, worried and nervous when I drive it. It helps if I turn the auto on/off idle stop off, but I must do that every time I start the car as it resets each time the car is turned off. Obviously I forget sometimes. It is a major concern that I feel the dealership is not taking seriously or showing much concern for my safety. Thank you for your help.

NHTSA ID

11762274

Incident

Sep 3, 2026

I have a 2025 Acura MDX SH-AWD. Several times while stopped in traffic, the Auto Idle Stop system shut the engine off and the vehicle displayed ‘RESTART ENGINE.’ The vehicle did not restart automatically. I'm concerned that this could cause a safety hazard if it happens in traffic. I want to file a safety complaint.

NHTSA ID

11761810

Incident

Aug 31, 2026

When at a red light the engine cuts off and does not restart when foot comes off the brake. Sometimes it takes several minutes to start. We were stuck in an intersection and almost were rear ended. Took it ti the dealership. had a new battery up in. By the time we got home, it did it again. Took it back to the dealership, they replaced the started. No problems for 4 months. Now it is doing the same thing again, along with the air conditioner not cooling. The first time we took it in for oil change we told them it was not cooling and were told there was nothing wrong with it. Took it back this weekend and found out there is a compressor issue. The compressors are not available for repair. Other minor issues are codes are randomly appearing on the gauges and the screen blacks out.

NHTSA ID

11761234

Incident

Mar 13, 2026

Idle Auto Start/Stop will not restart after cutting on leaving me stranded in traffic.

NHTSA ID

11759837

Incident

Aug 26, 2026

My 2025 Acura MDX suffers from a severe safety defect regarding the Auto Idle Stop (auto start-stop) system. When the vehicle comes to a complete stop at intersections or traffic lights, the engine shuts off as intended. However, upon releasing the brake pedal to accelerate, the engine completely fails to auto-restart.Instead of restarting, the vehicle drops out of the auto-restart sequence entirely, shifts itself out of drive, and displays a critical safety message on the dashboard: "To start engine: Brake + Push".This completely strands the vehicle in live traffic, forcing me to manually shift into Park, press the foot brake, and push the engine start button while traffic accumulates behind me. This creates an immediate rear-end collision hazard.The dealership has already attempted to diagnose and repair this issue under warranty by replacing both the vehicle's battery. This hardware replacement did not fix the problem; the failure continues to occur unpredictably less than a week (and 25 miles) after replacement. The root cause appears to be a software, Powertrain Control Module (PCM), or sensor tracking defect where the vehicle fails to recognize it is in an automated restart sequence.I am filing this complaint to be officially included in the ongoing NHTSA Engineering Analysis EA25004 regarding Honda/Acura Auto Idle Stop failures, as the current hardware recall remedies are entirely ineffective for the 2025 model year.

NHTSA ID

11759336

Incident

Aug 23, 2026

2025 Acura MDX – Auto Idle Stop Failure to Restart When my 2025 Acura MDX is stopped at a traffic light and the Auto Idle Stop system activates, the engine shuts off but on multiple occasions has failed to restart when traffic begins moving. The vehicle becomes immobilized in an active traffic lane. Vehicles behind me begin moving and honking while I am unable to move the vehicle. To regain operation, I have had to completely shut the vehicle off and restart it while stopped in traffic. I can prevent the occurrence by manually disabling Auto Idle Stop after starting the vehicle, but this requires me to remember to disable the system every time I drive. If I forget, I risk the vehicle shutting down and failing to restart at an intersection. This creates a serious safety concern for me and my passengers, including my child. I am concerned about being stranded in an intersection or other active traffic lane and potentially being struck by another vehicle. I believe the Auto Idle Stop system's failure to restart the engine presents an unreasonable safety risk and should be investigated.

NHTSA ID

11758463

Incident

Aug 16, 2026

The vehicle intermittently fails to restart after the Auto Idle Stop system shuts the engine off at a traffic stop. When this occurs, the vehicle remains disabled until it is manually restarted. This has now happened repeatedly, including twice within one recent week. The vehicle was purchased new on November 27, 2024, and currently has approximately 27,500 miles. The repair history for this same issue is: •September 19, 2025 — 13,841 miles: Battery replaced. •January 27, 2026 — 18,481 miles: Battery replaced again. •February 4, 2026 — 18,814 miles: Starter replaced. •August 14, 2026 — approximately 27,500 miles: Vehicle returned again for the same continuing problem. Diagnostics were performed, but no repair or resolution was provided. Despite replacement of two batteries and the starter, the defect continues. Our most recent experience with the dealership was particularly concerning. We were essentially told that they could not identify the problem and could not provide any further solution. That is not an acceptable outcome for a vehicle that can shut itself off while stopped in traffic and then fail to restart.

NHTSA ID

11757405

Incident

Aug 5, 2026

After an auto idle stop at a major intersection, car failed to restart automatically and was left stranded unable to restart the car. Car would not shut off or turn back on when using the power button and with foot on brake but had power but it was in limp mode - transmission warnings flashed and the D "for drive" on the screen at the drivers location. I called tripleA however before they showed up I was able to put the parking brake on and turn the car off and on ad it reset. This is similar to the issue was happening with my 2017 Honda Pilot where it would stall and not restart after the auto idle stop engaged. Very dangerous and difficult to troubleshoot when in that situation, surprised that this is still happening in Honda manufactured cars - this is very dangerous and needs to be addressed and investigated.

NHTSA ID

11757151

Incident

Aug 13, 2026

The automatic engine shutoff turned off the engine three times at stop lights and failed to restart. We were left stranded in the middle of the road, cars zipping by us fast. We felt very much at risk of being hit.

NHTSA ID

11757065

Incident

Aug 1, 2026

My vehicle is equipped with the auto stop, idle/start feature. I have had my vehicle completely shut off at least 6 times when I am at a complete stop. I have researched this problem among 2025 Acura MDX owners and it seems to be a recurring problem. The feature is suppose to save gas when I am at a stop and shut down the engine and then restart when I press the gas pedal but that is not happening.

NHTSA ID

11756817

Incident

Aug 13, 2026

I am reporting a safety issue with my 2025 Acura MDX involving the Auto Idle Stop/Start system. When the vehicle comes to a stop and the Auto Idle Stop system shuts the engine off, the engine does not always restart as it is supposed to. When this occurs, pressing the START/STOP button does not immediately restart the vehicle. This has left me unable to move the vehicle normally after the engine shuts off and creates a serious safety concern, particularly when stopped in traffic or at an intersection. I have reported this problem to my Acura dealership numerous times. I have been told that Acura is aware of the issue but has not developed a solution. Despite my repeated complaints, the problem remains unresolved. My vehicle currently has approximately 22,000 miles. I am concerned that the vehicle may fail to restart after Auto Idle Stop activates and leave me stranded in an active traffic lane or intersection, creating a risk of a collision. I am requesting that NHTSA document and investigate this safety issue involving the 2025 Acura MDX.

NHTSA ID

11756581

Incident

Apr 14, 2025

My vehicle was stopped at a busy intersection, idling in the automatic stop mode. When my husband moved his foot from the brake to the accelerator, the car stalled, orange alarm alerts went off, and the car was completely dead and stalled without power. The car needed to be restarted, and it took a few attempts to accomplish that task. I have had the same problem before with this car and have had it into the dealer at least two times without resolution.

NHTSA ID

11756035

Incident

Aug 10, 2026

Auto Idle Restart failed three times in traffic at red light. Have to shift to Park and push Start button. Nothing happens for several seconds, then engine starts.

NHTSA ID

11755686

Incident

Aug 8, 2026

The contact owns a 2025 Acura MDX. The contact stated that while at a complete stop at a traffic light, the vehicle unexpectedly shut off and failed to restart. After approximately 15 minutes, the vehicle restarted, and the contact drove into a parking lot before driving to the residence. No warning lights illuminated. The dealer was notified of the failure the following day, and a service appointment was scheduled. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 14,000.

NHTSA ID

11755315

Incident

Aug 5, 2026

Mileage

14,000 mi

I am writing to formally report a serious and recurring safety defect with my 2025 Acura MDX A-Spec (VIN [XXX]) involving the Auto Idle Stop system. The engine repeatedly fails to restart after the Auto Idle Stop feature shuts it off. When my wife releases the brake pedal (for example, at a traffic light), the vehicle either stalls completely or experiences a major delay before restarting sometimes lasting more than 20 seconds, leaving the my wife unable to accelerate. This creates an immediate and unacceptable safety hazard, particularly in intersections or heavy traffic. I previously brought the vehicle to Acura of Langley regarding this exact issue. Despite that visit, the problem has continued. Most recently, on today, while my wife was driving with my kids, the vehicle again entered Auto Idle Stop at a traffic light. When the light turned green, the engine completely shut off and would not restart for more than 20 seconds. This left her stranded in traffic and unable to move the vehicle, creating a clear risk of collision. This is not an isolated complaint. The National Highway Traffic Safety Administration (NHTSA) has opened Engineering Analysis EA25004 into precisely this condition “No Restart After Auto Start/Stop Engages” affecting, among other models, 2016–2025 Acura MDX vehicles. American Honda has also issued dealer communications specifically seeking 2023–2025 MDX vehicles with client complaints of no auto re-start after Auto Idle Stop for inspection prior to any repair attempts. Class-action investigations and prior litigation involving related Idle Stop failures further underscore the known nature and seriousness of this defect. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11754100

Incident

Jul 31, 2026

I am submitting this complaint regarding my **2025 Acura MDX**, which I currently lease. The vehicle has an ongoing starting system malfunction that has not been resolved despite multiple service visits. I believe this issue presents a significant safety risk. The primary issue involves the **Auto Idle Stop/Auto Start-Stop system**. When the vehicle automatically shuts off at a red light, stop sign, or while idling, it will occasionally fail to restart when I release the brake or attempt to accelerate. Instead of restarting normally, the vehicle hesitates, stutters, or remains off. This creates a dangerous situation because the vehicle is unexpectedly disabled while in traffic, increasing the risk of being rear-ended or causing an accident. In addition to the Auto Idle Stop issue, the vehicle also has problems during the initial startup. When I attempt to start the vehicle using the push-button ignition, it frequently fails to start on the first attempt. I often have to press the start button a second time before the engine starts, and even then, the engine stutters or hesitates before finally turning over. This should not occur in a brand-new 2025 vehicle. I have taken the vehicle to the dealership multiple times for this issue: * During the first visit, I was told the battery was the cause. * During the second visit, the starter was replaced. * After the problem continued, I returned again. The dealership tested both the battery and the replacement starter and advised that both components were operating properly. * The dealership then opened a case with Honda/Acura engineering for further investigation. Despite these repeated repair attempts, the issue remains unresolved. I have been told that it is likely a software issue and that engineers are "looking into it." In the meantime, I was instructed to simply disable the Auto Idle Stop feature every time I start the vehicle. This is not an acceptable solution. I do have videos but it will now allow me to up

NHTSA ID

11754009

Incident

Jul 30, 2026

Four times in 18 months, with the most recent happening last month and today, I was at a stoplight and turned my manual idle off. The light changed and the car would not move despite me stepping on the gas. It told me to restart the car which I did but the first attempt didn’t work to restart. After a few minutes I tried restarting again and it struggled but did. I was very worried as there was a car behind me who thought we were moving with the green light and fortunately he moved to the other lane to avoid a collision as it took me a minute to figure out the car had stopped before putting in my hazards.

NHTSA ID

11751202

Incident

Jul 17, 2026

I had driven 1.5 hours of highway driving. Exited highway and at the first stop light the car stalled on a busy four lane road. I have had the recall software update. Took a minute or 2 to get the car restarted

NHTSA ID

11749909

Incident

Jul 12, 2026

I was stopped at a red stop light waiting to turn left when my 2025 Acura MDX engine auto-stopped per the auto-stop feature. When the light turned green, I removed my foot from the brake and pressed the gas. The engine did not auto-start and displayed a message on the dash telling me to depress the brake and press the ignition button to continue driving. I did this several times, each time the dash would go black for a few seconds then come back up with the same message. Eventually, after getting the car to completely turn off, waiting 30 seconds, and restarting it, I was able to get the engine to start. While all of this was happening, I was passed unsafely by several angry drivers who were behind me, including one who tried to cut around me after I was able to get the car restarted, nearly clipping the front-right corner of my vehicle. I have an appointment with the dealer to have the issue investigated, but the appointment is not for another week. There was no indication of trouble prior to the first time this occurred. We have had this issue at least three times in the past week.

NHTSA ID

11748754

Incident

Jul 6, 2026

On June 9, 2026, my 2025 Acura MDX, with only 9,139 miles, stalled at a red traffic light after the Auto Idle Stop feature activated. The engine would not restart, leaving the vehicle disabled in an active traffic lane. I was unable to shift the vehicle out of Park and was stranded for approximately 5 to 10 minutes with my two young children in the back seat. The dashboard instructed me to fully depress the brake pedal and press the ENGINE START/STOP button to restart the vehicle, but repeatedly following those instructions did not restart the engine. There were no warning lights or other symptoms before the incident. I feared another vehicle would rear-end us because I could not move the vehicle out of the travel lane. After multiple attempts to turn the vehicle off and back on, it eventually restarted, allowing me to drive home. The vehicle was towed to the Acura dealership on June 10, 2026. The dealership inspected the vehicle, diagnosed a failed starter, and told me the failure was caused by the Auto Idle Stop feature. The starter was replaced, and I was instructed to disable the Auto Idle Stop feature every time I start the vehicle to help prevent the problem from happening again. The dealership has records of the repair, and the vehicle is available for inspection upon request.

NHTSA ID

11747615

Incident

Jun 9, 2026

The contact owns a 2025 Acura MDX. The contact stated that while stopped at a red light, the vehicle suddenly lost automotive power. The message, "Transmission System Failure - Apply Parking Brake while Parked - See Dealer," was displayed. The gear shifter indicator warning light was occasionally illuminated. The contact stated that while attempting to use the Push-To-Start feature to start the vehicle, the engine hesitated while turning over. The vehicle was taken to a local dealer and was diagnosed with starter failure. The vehicle was repaired under warranty. The manufacturer was not made aware of the failure. The failure mileage was approximately 10,000.

NHTSA ID

11747338

Incident

Sep 15, 2025

Mileage

10,000 mi

No restart after auto idle stop - Car fails to restart automatically after stop and releasing the brake pedal. This has happened on a number of occasions in the last few months.This can cause a dangerous condition that can can cause an accident if stopped in an intersection or a rear end collision as the driver behind assumes the vehicle will move but does not. Car has to be shut off to restart.

NHTSA ID

11747083

Incident

Jun 28, 2026

2025 Acura MDX will turn off with the auto on/off feature at red light but has had issue several times with turning back on. The car turns completely off and have to push start button to turn back on. On one occasion the same issue happened but would not immediately start with the push start again.

NHTSA ID

11746622

Incident

Jun 23, 2026