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.
2025 Acura MDX: won't start
13 of the 117 complaints about the 2025 Acura MDX describe won't start.
- owner complaints
- 13
- of this car's complaints
- 11%
- recalls
- 0
Is there a fix? 9 service bulletins cover this area of the car. See below
Won't start by model year
What owners say
20 minutes after parking my car, it would not start. Several different codes came up on the gauges - BRAKE issue; hill issue;stabilization issue - multiple icons and warnings. I ended up having to be jumped off.
Idle stop not functioning properly. Will get to a stop, and numerous times it will not start back up until you put it in park and restart it several times. Sometimes, it will not start on the 1st try from a cold start, or the starter will grind really slow. We have taken this to Acura several times, and they tell us it is a known problem, but just to turn the idle stop off each time.
the car shuts off at a red light, fails to auto-restart, forces the car into Park, and requires a full manual reboot or jumpstart while stuck in moving traffic. It also struggles to turn on at times mimicking a drained battery. I am needing to deactivate the auto start/stop feature in order for the vehicle to properly function. Vehicle will not start when parked at times.
While stopped at a red light at a busy intersection near an airport, the vehicle's Auto Idle Stop (AIS) system engaged and shut off the engine. When I attempted to restart by pressing the brake pedal — as instructed — the vehicle failed to restart. The dashboard displayed an error message reading "Idle Stop Function: Press Brake to Restart." My foot was on the brake pedal at the time; pressing it did not restart the engine. I then manually shut off the vehicle using the Engine Start/Stop button and attempted to restart it. The vehicle would not start. I remained stranded at the intersection for approximately 10 minutes before the vehicle finally restarted and allowed me to shift into Drive. I was the first car in the lane, so people kept piling up and honking behind me.
Description of Incident: While stopped at a red light at a busy intersection near a shopping district, the vehicle's Auto Idle Stop (AIS) system engaged and shut off the engine. When I attempted to restart by pressing the brake pedal — as instructed — the vehicle failed to restart. The dashboard displayed an error message reading "Idle Stop Function: Press Brake to Restart." My foot was on the brake pedal at the time; pressing it did not restart the engine. I then manually shut off the vehicle using the Engine Start/Stop button and attempted to restart it. The vehicle would not start. I remained stranded at the intersection for approximately 10 minutes. I had to call the cops for a patrol car because other cars were piling up behind me and I had my 6 month old son in the vehicle. Safety Impact: During this time, I was unable to move the vehicle from a live traffic intersection. This created an immediate safety hazard to myself, my family, and other drivers.
While stopped at a traffic light, the vehicle had auto shut off normally. However when I released the brake and pushed the gas it unexpectedly stalled and shut off without warning. When attempting to restart the vehicle, it would not start again. There were no prior warning indicators or messages suggesting an imminent issue. This created a hazardous situation as the vehicle was disabled in an active traffic lane. After several attempts, the vehicle either restarted after having set the emergency brake. The failure appears to be sudden and without driver input, raising concerns about reliability and safety in traffic conditions.
Last year, my 2025 Acura MDX was repaired under warranty for a known starter issue that is affecting all 2025+ MDX models. The issue is that the vehicle will stall or fail to start on random occasions leaving drivers stranded or stopped in traffic unable to move their vehicle. Honda and Acura are well aware of the fact that this is an issue, yet they continue to produce these vehicles with the same parts. This repair took several attempts and the dealership refused to even diagnose the issue for several months causing me to have to record each instance on my phone for proof. Once they eventually replaced the starter, the issue went away for approximately 10 months. Today, however, I was temporarily left stranded at a gas pump as my vehicle would not start. Honda and Acura dealerships are replacing these parts with the exact same part number, so the no-start condition comes back in about a year or less. It is incredibly dangerous to have a vehicle that you cannot move as anticipated, or if you’re in an area that you cannot leave or get away from potential danger because your vehicle won’t start. This is a less-than two-year-old vehicle that has now left me stranded on several occasions including in the middle of traffic on a motorway. I know for a fact that several other owners of the Acura MDX are having the exact same issue and ask that you please launch an investigation into this as Honda is well aware of it and still refuses to address the blatant safety risk it poses to its customers.
We have had multiple incidents when the car is at a stop light with the idle stop not active, the vehicle engine will just die. The light turns green and the vehicle is not running, it will take multiple times pushing the start button for it to start back up. This has resulted in multiple almost rear end incidents due to other drivers assuming we would go when light turned green. More recently this weekend on a trip from Columbus OH to St. Louis MO; stopped to get gas east of Indianapolis, after pumping gas the vehicle would not restart. It took multiple tries to get it to restart; this happened again the following day at a stop during the day at a shopping center, we ran in to get subs for lunch, came back out, would not start, I have a video of the sound and flashing lights but I can't upload a video here.
Incident 1 (Loss of Propulsion in Traffic) - 12/16/25 The vehicle failed to restart immediately after the auto start-stop system attempted to re-engage the engine. Upon attempting to accelerate, the engine did not restart, resulting in a complete loss of propulsion while in active traffic. The vehicle became temporarily inoperable and unresponsive, creating a hazardous condition with elevated risk of rear-end collision and inability to safely clear traffic or intersections. Incident 2 (Failure to Start – Reliability Concern) - 4/1/26 On a separate occasion, the vehicle failed to start entirely upon initial startup (first use of the day). The engine did not turn over as expected, rendering the vehicle inoperable. This incident raises significant concerns about system reliability and dependability, particularly given its occurrence independent of the auto start-stop event. Safety Concern: The first incident demonstrates a critical safety defect involving unexpected loss of propulsion in live traffic conditions. The second incident, while occurring at startup, indicates a broader pattern of failure affecting the vehicle’s ability to reliably start and operate. Together, these incidents suggest a potential defect in the starting/ignition or auto start-stop system that may compromise safe vehicle operation and increase the risk of crash or stranding.
On several occasions, when the vehicle has been driving and comes to a stop in traffic. the auto start stop kills the engine when the brake is fully depressed. When we take our foot off the brake the engine will not start and a notification is shown on the dash. to start the engine push brake and ignition button. When we follow those directions the it does not start the engine. It usually requires us to release brake several times and continue to push start button. This issue has almost caused two accidents because we are stuck and the traffic behind does not see brake lights, because we have to release the brake. This occurred on the interstate in heavy traffic, and was almost struck from behind by a vehicle traveling at interstate speed, because all vehicles went around us and the upcoming vehicle did to see brake lights.
Auto Idle Stop/Auto Start-Stop Issue- On multiple occasions, occurring randomly, the vehicle will not start at stoplights after auto-idle stop is engaged. Sometimes this happens after the vehicle has been running for over an hour. Currently, the vehicle must be completely powered down and then restarted to revive engine.
Service bulletins that may apply
Related recalls
No recalls on record for this model year.
Questions about the 2025 Acura MDX won't start
Is won't start a common problem on the 2025 Acura MDX?
13 of 117 owner complaints about the 2025 Acura MDX (11%) mention won't start. The model year with the most reports is 2025.
Is there a recall or service bulletin for this on the 2025 Acura MDX?
There are 0 recalls and 9 service bulletins for the same area of the car. Check them below with your VIN.
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