2019 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.

Car shifted on its own from drive to park right after warning lights stating Electrical Parking System then Emissions the Transmission came on while in stop and go traffic. Car had just come back from Acura mechanic 4 hours earlier as these warning lights had come when starting car. Immediately had car towed to dealership.

NHTSA ID

11752240

Incident

Jun 16, 2026

The subject 2019 Acura MDX model includes the tech package which adds several safety features that function through a windshield mounted camara/radar. The system has malfunctioned and none of the safety features are working. The dash displays the following messages: Collision Mitigation System Problem Adaptive Cruise Control Problem Lane Keeping Asist Problem Road Departure Mitigation System Problem automatic headlight system problem At the bottom of the dash, I see Brake System, Crash Warning and Lane Departure lights on as well. Acura is charging $2,319 to replace this unit in addition to a $270 diagnostic fee. This issue is widely reported as a significant issue in several model years for the MDX and should be part of a safety recall. The Acura technician acknowledged this issue is common. I should add this is the second major electronic issue with this MDX within the last several months. The prior issue was multiple system failure warnings that Acura determined were caused by a faulty wiring harness at a $1,604 cost, plus a $255 diagnostic fee. Please note I am the original owner of the vehicle and it has never been in a collision. Additionally, the system has recently mistakenly activated the brakes at very low speed and warned against collisions with other vehicles traveling in the opposite direction while on a curve.

NHTSA ID

11746803

Incident

Jun 19, 2026

While driving, the vehicle experienced a sudden internal mechanical and electronic transmission failure. Without warning, the vehicle shifted itself directly into Park while navigating the busy intersection of [XXX] and [XXX]. This caused a complete loss of propulsion and left the vehicle entirely immobilized in the middle of a high-speed junction. The vehicle could not be moved, creating an immediate, severe highway safety hazard that required an emergency 911 police response to manage traffic and protect the vehicle from being rear-ended. The dealership scan tool later pulled diagnostic code P0730 (Incorrect Gear Ratio) along with multiple clutch performance failures (P07A4, P07A2, P07A8). INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11746202

Incident

Jun 10, 2026

On [XXX], while traveling at highway speeds on [XXX], the vehicle suffered a sudden, complete loss of engine propulsion. The vehicle rapidly decelerated, refused to respond to accelerator input, and forced itself into a dangerous "Limp Mode" in live traffic, creating an immediate highway safety hazard. Multiple warning messages illuminated on the dashboard. The vehicle was towed to Mile High Acura under Repair Order #[XXX]. Diagnostic testing pulled stored Code P0087 for Low Fuel Pressure at the Fuel Rail. An inline fuel pressure gauge confirmed that the low-side fuel pressure was rapidly fluctuating between 55 and 64 PSI at idle. The dealership escalated the data to the Acura Corporate Tech Line (Ref #[XXX]), which reviewed the vehicle's onboard snapshot data and officially determined a terminal defect in the low-pressure fuel pump assembly, mandating the replacement of the low-side pump and both fuel relays. Dealership service records confirm that this vehicle previously had a low-pressure fuel pump recall performed in 2021 under NHTSA Campaign Number 21V-215 (Acura Code CAI). The sudden failure of this replacement component matches the exact failure conditions detailed in the subsequent NHTSA Campaign Number 23V-858 (Acura Codes KGC/KGD). In that expanded campaign, American Honda Motor Co. openly admitted to federal regulators that the early replacement "service parts" distributed and installed during the 21V-215 window were manufactured with the exact same defective, swelling density impellers prone to subsequent deformation and complete failure. Despite their own corporate Tech Line explicitly confirming that the root cause of this dangerous highway power loss was the low-pressure fuel pump—the exact component of the 21V-215 and 23V-858 safety recall campaigns—Acura Client Relations denied 100% safety remedy coverage. Acura refused to provide the technical basis for their denial in writing. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11745700

Incident

May 31, 2026

On 04/03/2026, 6:04 PM, Acura MDX 2019, Base, SH-AWD, at 105,254 miles on the odometer, posted U3000-49 control module internal electronic failure. The fault appears to be at the 36160-TYS-A02 camera assembly monocular results in a series of cascading errors on the dash with indicators on for LKAS (Lane Keeping Assist), ACC (Adaptive Cruise Control), CMBS (Collision Mitigation Brake System), brake and transmission warning lights that blink continuously. The sudden lost of safety system especially at highway speeds places extreme risk to occupants of vehicle and other drivers sharing the roadway. The current TSB 23-008 does not repair fault, origin of fault not software, but requires replacement of front camera assembly (36160-TYS-A02) and recalibration at owner expense. There appears to be a lot of 36160-TYS-A02 camera monocular that either have insufficient solder, cold solder, bad crimps or otherwise that over time results in failure.

NHTSA ID

11744263

Incident

Apr 3, 2026

Under normal driving conditions warning lights for "electric parking brake" and "emissions system problem" came on the dashboard and the 'brake' light began flashing. No change in performance. Auto parts store diagnostic indicated EVAP valve as the possible problem code, along with two other unrelated codes - none connected to brakes or emissions. The 12-volt battery tested strong. Drove another 100 miles with lights still on, but the 'brake' light would turn off after about 5 mins of highway driving/no braking. The next day the warning lights continued. After normal city driving I shut the car off, waited 30 seconds, pushed the start button twice (accessory mode) and held the brake pedal down while pulling up on the brake release button for 10 seconds. Started the car without any error messages.

NHTSA ID

11744197

Incident

Jun 12, 2026

When I was at 41,528 miles, May 18, the LKAS, ACC & RDMS errors all turned on at the same time. So those systems just stopped working randomly. When I restarted the car, all errors turned off but it turned on again after 10 days, May 28 with 91,966 miles. I brought it to the Acura dealership and they couldn't replicate it. I think this is an issue because one of the highlights of this car is safety but at random times, those safety systems suddenly stops working and the dealership couldn't do anything about it.

NHTSA ID

11741836

Incident

May 18, 2026

Clunking or Looseness in the Outer Tie Rod. The issue is related to TSB-B23-019 Bulletin. The exact same issue is occurring that has happened with years 2022-2023. I have had at the dealership to fix the issue and they never mentioned the outer tie rod cotter pin or castle nut loosening.

NHTSA ID

11740641

Incident

Jan 1, 2025

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 - 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.

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.