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.

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

"My 2016 Acura MDX completely seized on the highway after a loud knocking sound, which perfectly matches the connecting rod bearing failure under Recall 23V-751. Even if my specific VIN isn't showing up as open on the website, I know the NHTSA has a major open investigation into 1.4 million of these V6 engines because hundreds of vehicles are failing exactly like mine outside the original recall scope. I need Acura to open a corporate goodwill case to inspect my engine and cover this repair."

NHTSA ID

11762641

Incident

Sep 11, 2025

"Vehicle experienced a sudden flashing check engine light pulled over checked oil restarted car flashing check engine light went away then started flashing again a few miles down the road (Cylinder 3 misfire) accompanied by severe engine knocking. The engine locked up/seized while hot. car was stuck on the road and was unable to shift to neutral. After cooling down, the engine restarted but produces a heavy metallic scraping and loud squealing noise from internal friction. This matches the exact failure mechanism of connecting rod bearing failure under investigation PE25008, but Honda/Acura has excluded this VIN from active recalls. I was forced to pay $389 out-of-pocket for an emergency tow."

NHTSA ID

11762341

Incident

Sep 3, 2026

The contact owns a 2016 Acura MDX. The contact received notification of NHTSA Campaign Number: 26V365000 (Structure, Suspension) and would like to be removed from the recall distribution list. The vehicle was taken to a local authorized dealer, and recall repairs were performed. The vehicle was repaired. The manufacturer was made aware of the issue. The contact had not experienced a failure.

NHTSA ID

11762126

Incident

Aug 8, 2026

2016 Acura MDX. The red LED section of the inner tailgate taillight (lid light) has failed and no longer illuminates. The white backup bulb in the same assembly still works. The LED section is sealed inside the assembly and cannot be serviced, so the entire lid light must be replaced. This vehicle received safety recall M49 (NHTSA 19V-256) in 2019 for moisture intrusion into the inner taillights. The same failure has now occurred again. Honda's own Part 573 report for recall FLI (NHTSA 25V-259) states that the redesigned assemblies installed under 19V-256 do not sufficiently prevent moisture intrusion, and that moisture entered through two new pathways: between the gasket and the seal ribs of the lid light, and at the interface between the gasket and the body dust sealer. My failure appears to be exactly that condition. The NHTSA VIN lookup shows zero unrepaired recalls for this VIN. When I contacted Acura, I was told the issue was repaired in 2019. That response addresses M49, not FLI. I have not been able to get confirmation of whether FLI applies to this VIN or was ever performed. Loss of the rear position lights reduces visibility and is a citable equipment violation.

NHTSA ID

11760292

Incident

Aug 24, 2026

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.

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.

Service Bulletin - Under certain circumstances, after coming to a stop and engaging idle stop the vehicle may not restart automatically due to excessive cylinder pressure and/or low cranking torque. Typically, the client can immediately restart the vehicle by selecting Park and pressing the ENGINE START/STOP button.