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 complaint #11758463 — an unverified report by a vehicle owner.
The contact owns a 2020 Acura MDX. The contact stated that while driving approximately 35 MPH, there was an abnormal knocking sound coming from the vehicle before the vehicle stalled. The vehicle failed to restart. The maintenance warning light was illuminated. The contact stated that the failure was associated with NHTSA Campaign Number: 23V751000 (Engine and Engine Cooling). The vehicle was towed to the residence. The local dealer was contacted to schedule an appointment, but the vehicle had not been diagnosed or repaired. The manufacturer was not contacted. The approximate failure mileage was 60,541.
NHTSA complaint #11757385 — an unverified report by a vehicle owner.
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 complaint #11757405 — an unverified report by a vehicle owner.
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 complaint #11757151 — an unverified report by a vehicle owner.
Engine turns off while in drive or stopped at a red light/stop sign. It has happened 7-10 times withing the last couple of months, but 3-4 times within the last week. Out of the four times it happened, my family's safety was at risk, because the car was in drive, and could've caused us to get into an accident. During the other occasions, we were moving in reverse and stopped at a stop sign. Complaint was made with Acura of Bay Shore in Long Island, NY, at which time an update of computer engine was performed but issue wasn't fixed due to back-order part that needs to be replaced. Unfortunately, just yesterday (August 13, 2026) car turned off at light causing a road hazard to vehicles and my family stuck in a large intersection. Multiple engine lights turned on, but I was unable to turn the car on or move it. approximately 10 min later, I was able to turn the car on and move it to safe location. I spoke to Acura of Bay Shore, and it is a known issue but till this date, isn't fixed. Vehicle is a hazard and can cause serious bodily harm/or death. thank you
NHTSA complaint #11756994 — an unverified report by a vehicle owner.
The contact owns a 2020 Acura MDX. The contact stated that on six occasions the vehicle stalled and failed to restart immediately. The contact stated that while the idle button was on, the failure occurred. The contact was concerned about being in a crash. The vehicle was taken to the local dealer, where it was diagnosed, and two batteries were replaced, and a software update was performed. The dealer would be checking the software to be sure that it was operating as intended. The manufacturer was contacted, and a case was opened. The manufacturer provided a refund for the battery. The failure mileage was approximately 48,300.
NHTSA complaint #11757014 — an unverified report by a vehicle owner.
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 complaint #11757065 — an unverified report by a vehicle owner.
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 complaint #11756817 — an unverified report by a vehicle owner.
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 complaint #11756581 — an unverified report by a vehicle owner.
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 complaint #11756035 — an unverified report by a vehicle owner.
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 complaint #11755686 — an unverified report by a vehicle owner.
The contact owns a 2016 Acura MDX. The contact stated that while driving at an undisclosed speed, several unknown warning lights illuminated. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The dealer was not made aware of the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 133,000.
NHTSA complaint #11755328 — an unverified report by a vehicle owner.
I was driving home late at night with my family in the car. The car suddenly loss power and the check engine light came on and began flashing. I pulled over and turned the car off and back on. The light went away. I began driving again and after a short while, a bunch of lights popped up on the dashboard and the car began to loose power again and started making weird rattling noises from the engine. Just moments before pulling over again I realized the car was on fire and evasively pulled over and frantically got my sleeping children out of the car and we created distance from the vehicle since it was on fire underneath. We called the fire department and they responded very quickly and put out the fire. We secured a few belongings and the children’s car seats and my brother in law picked us up. The car was towed from the scene. I called the incident into the insurance the next day and filed a claim. After a few days once the adjuster came out, it was determined that the insurance company would not be covering the claim because the cause of the fire was internal engine failure. It had shot a bearing cap through the oil pan and that is what caused the fire. I contacted Honda about the issue and have yet to hear back from them. This was over a month ago. I am now stuck repairing the vehicle on my own since I cannot afford to take the car to the dealer and I am mechanically inclined as it is what I do for a living. The car is currently in my garage and after taking the engine apart, I found that the main bearing for cylinder #6 had failed and in turn fell apart and broken the piston for that cylinder and the broken debris destroyed the engine block and even bent the valves on the from head for that cylinder. I now have to rebuild my entire engine with no warning whatsoever that this was going to happened. The car was maintained on schedule and nothing was ever overlooked or not performed. It was a great car until the engine decided to grandad itself out of nowhere.
NHTSA complaint #11755216 — an unverified report by a vehicle owner.
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 complaint #11755315 — an unverified report by a vehicle owner.
The contact called on behalf of the owner of a 2016 Acura MDX. The contact stated that the owner reported an abnormal knocking sound coming from the engine while starting the vehicle. No warning light was illuminated. The vehicle was towed to the independent mechanic, where the timing belt tensioner was replaced; however, the failure persisted. The mechanic disassembled the oil filter and discovered metal shavings inside the filter. The mechanic related the failure to NHTSA Action Number: PE25008 (Engine). The manufacturer was notified of the failure; however, no assistance was provided because the VIN was not included in NHTSA Campaign Number: 23V751000 (Engine and Engine Cooling). The vehicle was not repaired. The failure mileage was approximately 60,000.
NHTSA complaint #11754481 — an unverified report by a vehicle owner.
I was merging onto the highway and when I attempted to accelerate, the engine warning light began to flash and the car could not accelerate. The engine began to make a rattling noise. I called the dealer and they asked if I could make it there (it was about 25 miles away). I said I would try. As I got about 10 miles away the noise grew louder and the oil light came on. I immediately pulled over. The dealer said the engine blew the connecting rod and destroyed the engine and the engine would need to be replaced. The car just had all the fluids replaced by the dealer 3 weeks prior. All service work over the 10 years was done by the dealer.
NHTSA complaint #11754357 — an unverified report by a vehicle owner.
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 complaint #11754009 — an unverified report by a vehicle owner.
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 complaint #11754100 — an unverified report by a vehicle owner.
Catastrophic Engine failure. Engine shook, then loss power. Multiple lights went off. Repair shop found metal shavings in the oil pan. Later diagnosed by specialist with cam/rocker engine issue. Recommended action was engine replacement.
NHTSA complaint #11751144 — an unverified report by a vehicle owner.
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 complaint #11751202 — an unverified report by a vehicle owner.