2016 Acura MDX

The Office of Defects Investigation (ODI) has received 414 reports of connecting rod bearing failures in the 3.5L V6 engine used in the following vehicles: Model Years (MY) 2018-2020 Acura TLX, MY2016-2020 Acura MDX, MY2016-2020 Honda Pilot, MY2018-2020 Honda Odyssey, and MY2017-2019 Honda Ridgeline.  The subject engine failures were analyzed as part of a Recall Query (RQ24013).  It was determined that these engine failures are outside the scope of Honda Recall 23V-751. Further, evidence gathered in conjunction with RQ24013 does not suggest this failure is caused by the same crankshaft manufacturing defect that is addressed by Honda in Recall 23V-751.  Based on analysis of data from RQ24013, NHTSA has closed that investigation. The significant number of reports of engine failure in vehicles outside the scope of RQ24013 presents a potential safety risk that warrants further investigation.  ODI is opening this Preliminary Evaluation (PE) to further evaluate the scope and severity of the potential problem and to fully assess the potential safety-related issues.  To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to NHTSA.gov.

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.

On November 8, 2024, the Office of Defects Investigation (ODI) opened Recall Query RQ24013 to assess the scope of Honda recall 23V-751 after receiving complaints that alleged connecting rod bearing failures in vehicles that were not within the scope of recall 23V-751. In November 2023, Honda recalled 248,999 various Model Year (MY)2016–2020 Honda and Acura vehicles equipped with the 3.5L V6 engine. Honda recalled these vehicles due to a crankshaft manufacturing defect that caused premature connecting rod bearing wear and engine seizure. While the out-of-scope failures involved in these complaints appear to have a very similar failure mechanism as the recalled engines, a thorough analysis of all available data from Honda has not indicated that the same manufacturing defect exists in the out-of-scope engines as the engines recalled by 23V-751. Based on this analysis ODI has determined that Honda has properly defined the scope of recall 23V-751. Consequently, ODI will close this RQ investigation.  NHTSA will continue to investigate these complaints of engine failure as part of a new Preliminary Evaluation Investigation (PE25008). The Agency reserves the right to take additional action if warranted by new circumstances.

The contact owns a 2016 Acura MDX. The contact stated that while driving approximately 65 MPH, the vehicle lost automotive power and the vehicle decelerated. During the failure, several warning lights illuminated and unknown messages were displayed. The vehicle was driven to the local mechanic who diagnosed that the engine rod bearings had failed and informed the contact that the engine needed to be replaced. The vehicle was not repaired. The local dealer was notified of the failure and informed that the vehicle was not included in the NHTSA Campaign Number: 23V751000 (ENGINE AND ENGINE COOLING). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 210,000.

NHTSA ID

11774407

Incident

Oct 24, 2026

Mileage

210,000 mi

There is a reaccuring safety defect issue where the engine completely shutts off and stalls without warning when the car comes to a stop. This can be at a stop sign, stop lights, or just stopping the car when in traffic, even on the highway. This is due to the IDS (Auto Idle Stop system). A couple exteme safetyhazards that have occured: The car has repeatedly shut down while we are in the middle of the highway during stop and go traffic leaving us stranded in in live lanes of traffic with the car just completely shutting down and glitching. It would take multiple attempts to turn the car on in order to get out of the situation. There have been close calls on rear-end collisions as a result of this. The issue also progressively worsens during super cold or super hot weather further reflecting the starter/software issues. During other occasions, the car completely failed to restart or delayed restarts that took 5+ hours long once the car "cooled down" from being parked in the sun. We have taken the car to an authrozied acura delarship on atleast two seperate occasion to address the racall issue. On top of these more severe situations, atleast once a week i will get stuck on a stop sign were the shuts down and then i am stuck for a few minutes trying to get it to turn on. However, the issue had ZERO improvement. The defect remains entirely unresolved and feels unsafe to operate. For the safety of my family and for your own massive legal and manufaturere liability due to the immenet threat of accidents, severe injury, or death, please resolve ASAP.

NHTSA ID

11772439

Incident

Oct 16, 2026

Water leakage into the right tailgate lid light assembly caused it to malfunction. In the photo you can see water pooled in the right lower corner. There is a recall for this specific issue for the year/make/model of my vehicle (NHTSA ID 25V259000). However my VIN is not included. I took my vehicle to the dealership and they confirmed that moisture was entering the tailgate lid light assembly which caused the light to fail. There was a warranty extension issued in July 2025 that expired in November 2025 related to this issue that applied to my specific vehicle. However I was not having this safety issue at the time and did not receive notification so I was unaware of the warranty extension. [XXX] I am reporting this as a safety complaint because it is the exact issue for which a recall was issued, yet Acura did not include my vehicle based on its VIN. Therefore it is possible they did not include all vehicles for which this problem may occur. Because the failure of the taillight due to a defect is a safety issue increasing crash risk, this should have been included in the recall rather than just a 6 month warranty extension. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11771422

Incident

Sep 18, 2026

Driving home from a trip June 2019 on the highway at 60mph with 3 children and my husband, my 2016 Acura MDX experienced complete engine failure - alarms started to sound and I experienced a loss of acceleration, lights in the dash included Engine Problem, Transmission Problem, Emission System Problem, Critical Failure Detected Stop Driving When Safe etc. The vehicle shifted into neutral. I was able to pull off the road onto the shoulder. The engine was still running but would not shift into park. I contacted Acura TLC to have the vehicle towed but we were stranded on the side of a very busy highway in 90 degree heat with 3 kids waiting. Not only was it unsafe to be driving 60mph and lose engine power, I had to also negotiate three lanes of traffic to safely reach the shoulder. The dealership that serviced my vehicle stated it needed a "software update" - the vehicle was with them the week before this happened for regular maintenance and they failed to do the supposed software update. I complained about engine issue in this vehicle from the first time I took for service and nothing was ever done about my complaints. I have all my service records from Acura service indicating my complaints. In 2026 we took the vehicle back to Acura for diagnostics and were told the engine and transmission needed to be replaced due to a KNOWN issue by Honda Motor Corp with the transmission cooler system contamination. The repair estimate is $36,506.15.

NHTSA ID

11770575

Incident

Jun 28, 2019

My 2016 Acura MDX (VIN [XXX]) is covered by Acura safety campaign 4170A8. The campaign covers rear subframe corrosion at the suspension mounting points that can cause the rear wheels to become misaligned or inadequately retained, affecting handling, stability, and braking. On XXX, I brought the vehicle to Sunnyside Acura, [XXX] (Repair Order XXX). The dealer did not perform the recall remedy and noted "cannot complete as rear toe arms are seized." They ordered replacement rear toe arms (52370-TZ5-A91 and 52375-TZ5-A91) that day. More than a month later, the recall repair has still not been completed: I filed a complaint with the dealership. They called me but did not follow through. On XXX, the dealer postponed the repair because no loaner vehicle was available. The repair was rescheduled for XXX. The dealer did not contact me. I contacted Acura Client Relations more than a week ago and have received no response. I am driving a vehicle with a known, open safety defect that Acura has acknowledged but has not repaired. I am asking NHTSA to help ensure Acura and its dealer complete the recall remedy promptly. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11765749

Incident

Aug 19, 2026

The contact owns a 2016 Acura MDX. The contact stated that while driving approximately 50 MPH, the vehicle suddenly lost motive power and failed to accelerate while the accelerator pedal was depressed. The check engine warning light illuminated. The contact stated that the failure posed a potential safety risk in daily traffic. The contact pulled over to the shoulder of the road, and the vehicle was towed to a local dealer for diagnosis. The dealer diagnosed the vehicle with engine bearing failure into the engine oil pan and cylinder #5 failure. The contact associated the failure with NHTSA Campaign Number: 23V751000 (Engine and Engine Cooling) and NHTSA Action Number: PE25008 (Engine). The manufacturer was notified of the failure by telephone. The failure mileage was approximately 150,000.

NHTSA ID

11764368

Incident

Sep 4, 2026

Mileage

150,000 mi

Heard a knocking noise in the engine, had it serviced at an independent mechanic (towed as to not create more damage and the knocking noise was louder). Mechanic told me that the rod bearing/engine had failed and would need to be replaced. $7000-$10000 for replacement. He also indicated that this was under recall for 2016-2020 cars. I checked my VIN and my car is not part of the recall but the car has 130000 miles and has been serviced regularly. I am requesting that it be part of the recall since this is a known/reported issue for this year/model. I called American Honda and they said because of the mileage and age, that it would not be part of the recall.

NHTSA ID

11764314

Incident

Sep 12, 2026

Car Keyless Entry Module/ TPMS Module having problem and alarms keep going off at anytime. It also stops car while driving because of no fob detection. It also automatically tries to turn the car on/off even when it was parked.

NHTSA ID

11762759

Incident

Sep 5, 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.

Owner Notification Letter - Under certain circumstances, after coming to a stop and the idle stop feature engaging, the vehicle may not automatically restart. Acura is providing a product update with a new PGM-FI software update to fix this issue.

Service Bulletin - An uneven sealing surface allows moisture to enter the inner taillight(s), causing one or both of the inner taillights not to work.

Dealer Message - Acura is also implementing an additional (1) twenty-four (24) month period for 2015 model year Acura TLX vehicles, commencing at the expiration of the 10-year warranty extension period for each vehicle, and (2) eighteen (18) month period for 2016 model year Acura TLX/MDX vehicles, commencing at the expiration of the 10-year warranty extension period for each vehicle, for valve adjustment and starter replacement related to this condition under warranty.

Service Bulletin - An uneven sealing surface allows moisture to enter the inner taillight(s), causing one or both of the inner taillights not to work.