2017 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.

I am reporting repeated failures of the front safety camera / Collision Mitigation Braking System (CMBS) on my 2017 Acura MDX Tech (FWD). The vehicle has experienced intermittent and sudden loss of all ADAS safety functions, including CMBS, Lane Keeping Assist, Adaptive Cruise Control, and Road Departure Mitigation. The failures occur without warning, while driving at normal speeds. The dash displays “Safety Support System Problem,” “Collision Mitigation System Problem,” “Lane Keeping Assist Problem,” and related alerts. When this happens, all forward‑facing safety systems shut down, increasing the risk of collision. The issue is persistent and unpredictable. It has occurred in clear weather, dry roads, and normal driving conditions. The vehicle does not have the Advance package or surround‑view system; this is the standard Tech‑package front camera. Multiple Acura service departments have confirmed the problem is caused by a faulty front monocular camera module (part number 36160‑TZ5‑A36). Acura has superseded this part several times (A63, A64, A65, A66), indicating an ongoing design or reliability issue. Replacement cost is extremely high, and the failure disables federally‑relevant safety systems. This is a safety‑critical component. When the camera fails, the vehicle loses collision‑avoidance capability, lane‑keeping assistance, and adaptive cruise control. The failure happens while the vehicle is in motion, creating a risk of rear‑end collisions or lane‑departure accidents. I am requesting NHTSA review this issue for potential defects in the Acura MDX front safety camera system.

NHTSA ID

11755602

Incident

Aug 6, 2026

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 ID

11755216

Incident

Jun 21, 2026

Problem Description: I am reporting a safety-related issue affecting multiple driver assistance systems on my 2017 Acura MDX. While driving, the vehicle displays several warning messages at the same time, including: Adaptive Cruise Control (ACC) Problem Lane Keeping Assist System (LKAS) Problem Road Departure Mitigation (RDM) System Problem Collision Mitigation Braking System (CMBS) Problem When these warnings appear, all of these safety systems become unavailable. The warning indicators remain on, and the systems do not function even after restarting the vehicle. The 12-volt battery was replaced approximately one month before this issue began, and the engine starts and runs normally. Despite the new battery, the warnings continue to appear, making the vehicle's advanced safety features unusable. This appears to be a widespread issue reported by many owners of the 2017 Acura MDX. Since multiple critical safety systems fail simultaneously, I believe this may be related to a defect in the vehicle's electrical system, charging system, control modules, wiring, or communication network. Because these features are designed to help prevent accidents, their sudden loss creates a significant safety concern. I respectfully request that Acura investigate this issue and consider issuing a recall or extending warranty coverage if a common manufacturing defect is identified.

NHTSA ID

11754620

Incident

Jul 18, 2026

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 ID

11754357

Incident

Jul 25, 2026

The contact owns a 2017 Acura MDX. The contact stated that the second-row passenger’s side seat belt became stuck and failed to retract as needed, causing the seat belt to become inoperable. The cause of the failure was not yet determined. The local dealer and manufacturer were notified of the failure, but no assistance was provided. The failure mileage was approximately 200,000.

NHTSA ID

11750292

Incident

Jul 2, 2026

Mileage

200,000 mi

I am reporting a severe safety defect regarding the sudden, unprovoked failure of the AcuraWatch driver-assist camera system (affecting LKAS, ADAS, and the Collision Mitigation Braking System), which directly and unexpectedly alters the vehicle’s powertrain and driving dynamics without driver input. While driving, the front windshield monocular camera module experienced an internal electronic failure, immediately lighting up multiple critical safety warning indicators on the dashboard and permanently disabling all forward collision prevention and lane-keep capabilities. I urge NHTSA to open a safety defect investigation into 2016–2019 Acura MDX models regarding camera system degradation and its hazardous, cascading impact on transmission shift timing and vehicle deceleration behavior.

NHTSA ID

11748193

Incident

May 1, 2026

We are asking for your assistance and getting our reimbursement back from Acura/Honda automotive for a safety recall for our rear tail light which had moisture which was an NHTSA safety recall We purchased and had replaced the rear tail plate that had been recalled prior to the recall coming out. We have given them all this information and they still have not provided us with a refund for the safety recall on the tail light on our vehicle this has been going on for a couple years. The individuals at Honda automotive corporate are very disrespectful and as a handicap woman who uses this vehicle as a family vehicle it was a great essence to get the taillight part repaired and purchased because I almost got into a couple accidents because the tail lights were not working. We have submitted all our reimbursement paper to them as well as the receipts and proof of payments and they still have not refunded us we ask for your help in this matter as it is greatly appreciated because this was a safety recall and they know that, and they still have disregarded reimbursing us for the parts that we purchased prior to the recall, if you need anything else from us, we have submitted our reimbursement form our payment proof, as well as the proof that it was purchased and done at the Acura certified dealership. Our car is a certified vehicle that we purchased from Acura and we always get our work for service done at certified Acura dealerships. Any assistance in this matter would be greatly appreciated as this has been going on for a couple years and I tried to work with them, but they are very difficult in getting our money back every time they ask for something we send it and they say they need more. It is like back-and-forth. It has been an extremely stressful situation for something that is a safety issue and that was a defect by our automotive maker and we should not have to go through that as a consumer.

NHTSA ID

11748123

Incident

Aug 12, 2024

Safety Recall# AOT 2014-20 MDX REAR SUBFRAME REPAIR SAFETY RECALL June 2026 we were made aware that our 2017 Acura MDX SH – AWD had a recall for the rear subframe Safety repair. We immediately contacted Acura Joe Rizza Orland Park, Illinois at the time they said they did not have the Safety recall parts available for the rear subframe but they were on order so they scheduled us to bring the vehicle in on July 1, 2026 to complete the safety recall. invoice included. Just prior to this in May 2026 we were experiencing safety issues with our vehicle, vibrating very severely and pulling when we brought it in they told us it was the drive propeller shaft which, as you will see in the enclosed documents that when the rear subframe prematurely rusts it causes key suspension problems, especially with the drivetrain and propeller shaft . As this was a safety issue, and we felt very concerned about this because the car was NOT safe to drive. We had it repaired prior to receiving this safety recall soon after rear subframe which all makes vehicle unsafe. There’s direct correlation that safety recall the premature rust on the rear subframe which caused structural integrity to degrade and caused severe vibration and pulling on our propeller shaft. Due to the severity and safety as we felt very concerned for our safety with this severe vibration we Paid to have the propeller shaft replaced, then found out a couple of weeks later that the actual rear subframe that has a direct correlation to the propeller shaft get recalled for safety issues. Our vehicle vehicle is a certified vehicle always serviced at Acura dealerships as shown on a car fax .Due to these Safety reasons and the paperwork provided along with the invoices we are asking for a refund in the amount that we paid in total $1313.37 for repair of the propeller shaft which the safety recall the rear subframe caused it to misalign cause abnormal noises severe vibrations SEVERE safety issues for Our family vehicle.

NHTSA ID

11747996

Incident

May 13, 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.

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.

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