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2021 Acura Tlx

Owner reports · Recalls · Investigations

Similar to other model years

Owner complaints for the 2021 Acura Tlx do not stand out strongly from the model-year median of 65.

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How this year compares

Owner complaints by model year

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Counts vary with age, sales and reporting. They are not failure rates.

What owners reported most

All reported categories

Tap a category to read its complaints. One report may name several components.

When problems were reported

Mileage at the reported incident

Limited mileage data: 7 of 68 reports include usable mileage. There isn’t enough coverage to show a useful chart.

NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.

What to inspect

Issues worth paying extra attention to based on owner reports.

  • Power Train. Review the 26 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Electrical System. Review the 9 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Service Brakes. Review the 9 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →

NHTSA owner reports · September 18, 2026 snapshot.

3 crash reports0 fire reports3 injury reports

Forward Collision Avoidance complaints

7 reports
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Mileage unknown · Dec 28, 2025
Forward Collision AvoidanceLane Departure

Problem with all safety feature sensors like Adas, lane assistance. Small car icon which always green turned orange, and none of those features working.

NHTSA ODI #11707420

Mileage unknown · Feb 2, 2025
Forward Collision Avoidance

On a slightly snowing evening driving on the highway, a warning was displayed indicating "Some Driver Assist Systems Cannot Operate, Radar Obstructed" and the green icon turned orange. Traveling about 45 mph, I slowed down to get over and the car drastically slowed down without me pressing the brake. After about 10 more minutes …

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On a slightly snowing evening driving on the highway, a warning was displayed indicating "Some Driver Assist Systems Cannot Operate, Radar Obstructed" and the green icon turned orange. Traveling about 45 mph, I slowed down to get over and the car drastically slowed down without me pressing the brake. After about 10 more minutes of driving the icon turned green again. This has happened on more than one occasion creating a serious safety risk, typically during inclement weather.

NHTSA ODI #11640171

Mileage unknown · Aug 30, 2023
Forward Collision AvoidanceUnknown Or Other

I was traveling on the highway (on a very rainy day), when my car's green signal lights and orange engine light began blinking. Immediately, an orange warning sign on the dash read, "Some Driver Assist Systems Cannot Operate, Radar Obstructed". A few seconds after that occurred, I accelerated to pass a vehicle & as soon as I swi…

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I was traveling on the highway (on a very rainy day), when my car's green signal lights and orange engine light began blinking. Immediately, an orange warning sign on the dash read, "Some Driver Assist Systems Cannot Operate, Radar Obstructed". A few seconds after that occurred, I accelerated to pass a vehicle & as soon as I switched lanes to get over, my car went from speeds of about 85 MPH, abruptly down to 15-20 MPH. My safety was immediately put at risk as the driver I passed began tailgating me as if my actions were intentional. I attempted repeatedly to speed up, but my car just wouldn't go any faster. Once, I proceeded to get in the right line, I was almost hit by a group of tractor trailers. I called my spouse in a panic, who advised me to get off at the next exit. I followed his advice, pulled over, turned off my car & started it again. The lights turned off & proceeded to get back on the highway. About 3 minutes later, the orange light flashed the same message, "Some Driver Assists...." I immediately called Leith Acura & tried explaining what was occurring. Once hanging up with Leith, the dash continued to display "call ended" with Leith's number flashing every few seconds. The radio also turned off with a "No audio connection for FM Radio". Too afraid to accelerate, I drove minimal speed all the way to VA. Also afraid to drive back in the same condition, I contacted Crown Acura, who set an appointment for June 23, cancelling Leith. Service advisor [XXX] informed me that the technicians were unable to duplicate what occurred and placed me in a rental vehicle until my car was assessed and diagnosed. The next day I was informed my vehicle was ready and told the technology was reset. Before & after this, my phone calls are stuck in a limbo state where it will ring through Bluetooth, the number will display, but there is no way to pick up the call via phone or car display. "Brake" warning also blinks when there are no objects in front of me. *I have videos* INFORMATION REDACTED PURSUANT TO THE FREEDOM O

NHTSA ODI #11541773

Mileage unknown · Feb 16, 2023
Forward Collision Avoidance

On two occasions the Collision Mitigation Braking System (CMBS) has improperly activated with HARD braking leaving me fighting for control. On one occasion, I was driving at 35 MPH on a divided boulevard in my home subdivision with no vehicles in sight. The second occasion occurred on the Florida Turnpike at 75 MPH while in the …

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On two occasions the Collision Mitigation Braking System (CMBS) has improperly activated with HARD braking leaving me fighting for control. On one occasion, I was driving at 35 MPH on a divided boulevard in my home subdivision with no vehicles in sight. The second occasion occurred on the Florida Turnpike at 75 MPH while in the outside lane. There was no vehicle in front of me or to the side at that time. That was a scary moment. I want to emphasize that the CMBS employed HARD braking along with the flashing dash warning. After each instance I took the vehicle to an Acura dealer. First to Fountain Acura in Orlando who could find no DTC codes and blew me off by telling me it was my E-Pass transponder and window tint that caused the problem. That was utter nonsense. The second time I took the vehicle to AutoNation Acura North Orlando where I had purchased the vehicle as Certified Pre-owned (CPO) in April of 2022. They took my concern seriously, provided a loaner and kept the vehicle for four days. They also were unable to duplicate the issue and could find no DTC codes. They called Honda’s “tech line” and told me that same nonsense about tint and transponders. This “washing of hands” rather than taking ownership of this life-threatening problem made me start looking for others with the same issue. No surprise, I found 103 other Acura 2021 TLXs as well as RDXs and Honda models with NHTSA complaints for the same exact experience I had. Is AHM’s “tech line” telling all owners it is their fault for the improper activation of the CMBS? It seems to me that a change in the CMBS triggering algorithm needs to be made otherwise the more vehicles with the defective algorithm the more crashes will occur. This improper activation seems unique to 2021 vehicles. NHTSA records currently show no similar complaints for 2020, 2022, or 2023 model year vehicles.

NHTSA ODI #11507643

Mileage unknown · Jan 7, 2023
Forward Collision AvoidanceCrash

My wife and I were on the first day of vacation, driving from Virginia to FL by way of SC. Around 1pm I was driving the car on interstate 20 West in South Carolina near Bishopville. There were no cars in my lane in front of me and the car suddenly activated what Acura refers to as the CMBS system. The purpose of this is to stop …

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My wife and I were on the first day of vacation, driving from Virginia to FL by way of SC. Around 1pm I was driving the car on interstate 20 West in South Carolina near Bishopville. There were no cars in my lane in front of me and the car suddenly activated what Acura refers to as the CMBS system. The purpose of this is to stop us if it thinks we are going to run into another vehicle. I'm not 100% sure but I think this is related to the adaptive cruise control. We had not used cruise control that day because traffic on rt 95 South was extremely heavy. We had finally turned off on Rt 20 and traffic wasn't as heavy so we felt we could safely use the cruise control. We were traveling at about 73 mph and the car suddenly started hard braking. It was flashing BRAKE in big letters in the dash. There was another vehicle behind so I kept pushing on the gas pedal to keep going but the car literally would not release the brakes. The vehicle from behind hit us. There is a video cam in my car so I have a video that shows the car traveling smoothly then all at once bouncing and jerking as it keeps applying the brakes. We also have photos of the front of the car showing that the cameras that this system uses were clear and unobstructed. The other driver was charged but it was absolutely the fault of the Acura for this malfunction. Acura Roadside Assistance tried to tell us how to disable this system but the info they provided was for another year model and didn't work. We went on YouTube and found the correct information and have disabled this system. There were other videos on YouTube describing this exact issue with this system failure with Acura vehicles. We have also filed a report with Acura Customer Care. It is case #[XXX]. We have also reported this to our insurance company (Travelers) and to State Farm, the company that is handling the claim for repair. The State Farm Claim # is [XXX]. INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI #11500621

Mileage unknown · Jun 5, 2022
Forward Collision Avoidance

In many instances while driving about 40-60 MPH and with no vehicles in front the car would suddenly brake.

NHTSA ODI #11467646

11 miles · Mar 7, 2022
Forward Collision AvoidanceService Brakes

The contact leased a 2021 Acura TLX. The contact stated that while driving the vehicle, a loud abnormal, squealing noise would emit from the brake pedal upon depression without warning. The contact had taken the vehicle back to the dealer where they acknowledged the failure but stated that the parts for the repair were not yet a…

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The contact leased a 2021 Acura TLX. The contact stated that while driving the vehicle, a loud abnormal, squealing noise would emit from the brake pedal upon depression without warning. The contact had taken the vehicle back to the dealer where they acknowledged the failure but stated that the parts for the repair were not yet available. The contact was given a loaner vehicle of the same model; however, the same failure occurred with the loaner vehicle. The contact returned to the dealer for the third time and was given a loaner vehicle of a different model. Upon return of the original vehicle, the brake noise had stopped; however, the forward collision avoidance brake warning light would intermittently illuminate on the instrument panel without incident. The vehicle was taken back to the dealer where she was informed that the electrical system needed to be reset; however, once the system was reset, the original brake noise failure returned. The vehicle was taken back to the dealer where it remained in their possession. The manufacturer had been notified of the failure and a case was filed. The vehicle had yet to be repaired. The failure mileage was 11.

NHTSA ODI #11455498

Official recalls

4

26V332000 · Air Bags:sensor:occupant Classification:front Passenger

May 21, 2026

Honda (American Honda Motor Co.) is recalling certain 2018-2021, 2023 Acura TLX, 2019-2024 RDX, 2017-2020, 2022-2026 MDX, 2017-2021, 2023, 2025 Honda Ridgeline, 2017-2022 Pilot, 2019-2021 Passport, 2018-2026 Odyssey, 2019-2022 Insight, 2019-2021 HR-V, 2018-2020 Fit, 2020-2022 CR-V Hybrid, 2017-2022 CR-V, 2017-2018, 2021 Civic Type R, 2017-2021 Civic hatchback, 2016-2020 Civic coupe, 2016-2022 Civic, 2017-2022 Accord Hybrid, and 2016-2022 Accord vehicles. The front passenger seat weight sensor may crack and short circuit, which can cause the air bags to deploy unintentionally during a crash.

Consequence & remedy

Consequence: Air bags that deploy unintentionally during a crash increase the risk of injury.

Remedy: Dealers will replace the seat weight sensors, free of charge. Owner notification letters were mailed July 7, 2026. Owners may contact Honda's customer service at 1-888-234-2138. Honda's numbers for this recall are BOL, WO9, OOA, WOM, XOH, NOC, POD, BOE, UOF, POB, EOG, AOI, QO8, TOJ, DO7, and SOK. This recall expands previous NHTSA recall number 24V064. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning May 29, 2026.

25V391000 · Service Brakes, Hydraulic:pedals And Linkages

Jun 12, 2025

Honda (American Honda Motor Co.) is recalling certain 2021-2025 Acura TLX, 2023-2025 Acura MDX, and 2023-2025 Honda Pilot vehicles. The brake pedal pivot pin was not secured properly, which can cause the pedal to shift out of position. As such, these vehicles fail to comply with Federal Motor Vehicle Safety Standard numbers 108, "Lamps, Reflective Devices, and Associated Equipment" and 135, "Light Vehicle Brake Systems."

Consequence & remedy

Consequence: A brake pedal that shifts out of position can prevent the driver from applying the brakes as intended, increasing the risk of a crash or injury.

Remedy: Dealers will inspect and replace the brake pedal assembly as necessary, free of charge. Owner notification letters were mailed July 29, 2025. Owners may contact Honda's customer service at 1-888-234-2138. Honda's numbers for this recall are FLX and XLY.

24V950000 · Fuel System, Gasoline:storage:tank Assembly

Dec 19, 2024

Acura (American Honda Motor Co.) is recalling certain 2021-2023 TLX vehicles. The fuel filler neck and fuel tank may have been improperly welded, which can result in a fuel leak.

Consequence & remedy

Consequence: A fuel leak in the presence of an ignition source increases the risk of a fire.

Remedy: Dealers will replace the fuel tank assembly, free of charge. Owner notification letters were mailed February 3, 2025. Owners may contact Honda customer service at 1-888-234-2138. Acura's number for this recall is JKX.

24V064000 · Air Bags:sensor:occupant Classification:front Passenger

Feb 1, 2024

Honda (American Honda Motor Co.) is recalling certain 2020-2022 Pilot, Accord, Civic sedan, HR-V, Odyssey, 2020 Civic coupe, Fit, 2021-2022 Civic hatchback, 2021 Civic Type R, Insight, 2020-2021 CR-V, CR-V Hybrid, Passport, Ridgeline, Accord Hybrid, 2020 Acura MDX, 2022 Acura MDX, 2020-2022 Acura RDX, and 2020-2021 Acura TLX vehicles. The front passenger seat weight sensor may crack and short circuit, failing to suppress the air bag as intended.

Consequence & remedy

Consequence: An air bag that deploys unintentionally during a crash can increase the risk of injury.

Remedy: Dealers will replace the seat weight sensors, free of charge. Owner notification letters were mailed March 28, 2024. This is a phased recall. Owners may contact Honda customer service at 1-888-234-2138. Honda's numbers for these recalls are XHP and VHQ.

Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗

NHTSA investigations

2

DP26001 · All Wheel Drive Allegation

Opened Mar 6, 2026 · Closed Aug 4, 2026

Status: closed (inferred from source dates) · Power Train:automatic Transmission; Power Train:automatic Transmission:internal:shaft:output; Power Train:transfer Case (4-WHEEL Drive)

The Office of Defects Investigation (ODI) has completed its review of a Petition dated January 9, 2026, requesting an investigation into the loss of the optional all-wheel drive capability in model year (MY) 2021-2023 Acura TLX and MY 2022-2023 Acura MDX vehicles. The Petition alleges failures in the interfacing splines between the front wheel drive transaxle and the rear wheel drive power take off unit. Failure of these splines prevents the transfer of drive power to the rear axle, making the vehicle front wheel drive only. The Petition further alleges that this failure reduces vehicle directional control. Most traditional AWD systems utilize mechanical and passive measures. These systems have the tendency to distribute torque along the path of least resistance, such as a wheel that has lost contact with the ground or is on a low friction surface such as ice. To compensate for this, many manufacturers use the brake system to redirect torque to the wheels with more traction.  However, in this style of AWD system, a failed drive shaft or similar disconnection prior to the brakes often results in drive power being lost to the disconnected component. The consequence of this loss is the inability to maintain speed with surrounding traffic which increases the risks of collisions and injuries to the vehicle occupants. The Subject Vehicles are built upon a platform that was designed primarily as Front Wheel Drive (FWD). The SH-AWD system functions more as a performance enhancement feature rather than a stability feature. Even if the SH-AWD is nonoperational, the vehicles retain full mobility via FWD. In addition, the Vehicle Stability Assist (VSA) remains functional, ensuring directional stability through traditional engine and brake-based traction control. Although the condition raised by the Petitioner may degrade the vehicle’s performance characteristics, there is insufficient information to indicate a potential unreasonable safety risk. ODI reviewed 62 Vehicle Owner Questionnaires (VOQs) and several EWR Field Reports alleging the loss of SH-AWD and its impact on the driving dynamics of the subject vehicles. During its analysis, ODI determined that the failure is localized to the mechanical interface between the FWD transaxle and the PTU. Specifically, the failure is the shearing or stripping of the interfacing splined shafts between the FWD transaxle and the PTU, resulting in a permanent loss of torque transfer to the rear of the vehicle. Upon reviewing the technical details of SH-AWD, ODI has found that this failure does not result in any loss of motive power or lead to a loss of vehicle control. Several complaints indicated that the operators were unaware of the mechanical fault until encountering a low friction surface or the condition was identified by a technician during routine maintenance. The SH-AWD system lacks any form of direct feedback for monitoring real time torque transfer to the rear wheels. Therefore, the system will continue to display information indicating power is being supplied to the rear wheels even when power is actually only supplied to the front wheels. ODI’s review did not identify sufficient evidence to indicate that the misinformation has presented a safety issue in the field. ODI did not identify any reports of loss of motive power or vehicle control that could be attributed to the loss of SH-AWD. ODI is not aware of any crashes involving the Subject Vehicles that resulted from the loss of SH-AWD. After thoroughly assessing the material submitted by the Petitioner, consumer complaint information in NHTSA’s databases, and other relevant information already in possession of the Agency, NHTSA has not found sufficient evidence to indicate that the loss of AWD as alleged by the Petitioner is likely to present a safety related defect that would warrant a formal investigation. After full consideration of the available information, and in view of NHTSA’s enforcement priorities, the Petition is denied.  A denial report will be posted in the Federal Register.  The closing of the petition does not constitute a finding by NHTSA that a safety related defect does not exist, and the agency reserves the right to take additional action if warranted by future circumstances.  The Petition can be viewed at NHTSA.gov under ODI Number 11712885.

Additional source detail variants (3)

Power Train:automatic Transmission

The Office of Defects Investigation (ODI) has completed its review of a Petition dated January 9, 2026, requesting an investigation into the loss of the optional all-wheel drive capability in model year (MY) 2021-2023 Acura TLX and MY 2022-2023 Acura MDX vehicles. The Petition alleges failures in the interfacing splines between the front wheel drive transaxle and the rear wheel drive power take off unit. Failure of these splines prevents the transfer of drive power to the rear axle, making the vehicle front wheel drive only. The Petition further alleges that this failure reduces vehicle directional control. Most traditional AWD systems utilize mechanical and passive measures. These systems have the tendency to distribute torque along the path of least resistance, such as a wheel that has lost contact with the ground or is on a low friction surface such as ice. To compensate for this, many manufacturers use the brake system to redirect torque to the wheels with more traction.  However, in this style of AWD system, a failed drive shaft or similar disconnection prior to the brakes often results in drive power being lost to the disconnected component. The consequence of this loss is the inability to maintain speed with surrounding traffic which increases the risks of collisions and injuries to the vehicle occupants. The Subject Vehicles are built upon a platform that was designed primarily as Front Wheel Drive (FWD). The SH-AWD system functions more as a performance enhancement feature rather than a stability feature. Even if the SH-AWD is nonoperational, the vehicles retain full mobility via FWD. In addition, the Vehicle Stability Assist (VSA) remains functional, ensuring directional stability through traditional engine and brake-based traction control. Although the condition raised by the Petitioner may degrade the vehicle’s performance characteristics, there is insufficient information to indicate a potential unreasonable safety risk. ODI reviewed 62 Vehicle Owner Questionnaires (VOQs) and several EWR Field Reports alleging the loss of SH-AWD and its impact on the driving dynamics of the subject vehicles. During its analysis, ODI determined that the failure is localized to the mechanical interface between the FWD transaxle and the PTU. Specifically, the failure is the shearing or stripping of the interfacing splined shafts between the FWD transaxle and the PTU, resulting in a permanent loss of torque transfer to the rear of the vehicle. Upon reviewing the technical details of SH-AWD, ODI has found that this failure does not result in any loss of motive power or lead to a loss of vehicle control. Several complaints indicated that the operators were unaware of the mechanical fault until encountering a low friction surface or the condition was identified by a technician during routine maintenance. The SH-AWD system lacks any form of direct feedback for monitoring real time torque transfer to the rear wheels. Therefore, the system will continue to display information indicating power is being supplied to the rear wheels even when power is actually only supplied to the front wheels. ODI’s review did not identify sufficient evidence to indicate that the misinformation has presented a safety issue in the field. ODI did not identify any reports of loss of motive power or vehicle control that could be attributed to the loss of SH-AWD. ODI is not aware of any crashes involving the Subject Vehicles that resulted from the loss of SH-AWD. After thoroughly assessing the material submitted by the Petitioner, consumer complaint information in NHTSA’s databases, and other relevant information already in possession of the Agency, NHTSA has not found sufficient evidence to indicate that the loss of AWD as alleged by the Petitioner is likely to present a safety related defect that would warrant a formal investigation. After full consideration of the available information, and in view of NHTSA’s enforcement priorities, the Petition is denied.  A denial report will be posted in the Federal Register.  The closing of the petition does not constitute a finding by NHTSA that a safety related defect does not exist, and the agency reserves the right to take additional action if warranted by future circumstances.  The Petition can be viewed at NHTSA.gov under ODI Number 11712885.

Power Train:automatic Transmission:internal:shaft:output

The Office of Defects Investigation (ODI) has completed its review of a Petition dated January 9, 2026, requesting an investigation into the loss of the optional all-wheel drive capability in model year (MY) 2021-2023 Acura TLX and MY 2022-2023 Acura MDX vehicles. The Petition alleges failures in the interfacing splines between the front wheel drive transaxle and the rear wheel drive power take off unit. Failure of these splines prevents the transfer of drive power to the rear axle, making the vehicle front wheel drive only. The Petition further alleges that this failure reduces vehicle directional control. Most traditional AWD systems utilize mechanical and passive measures. These systems have the tendency to distribute torque along the path of least resistance, such as a wheel that has lost contact with the ground or is on a low friction surface such as ice. To compensate for this, many manufacturers use the brake system to redirect torque to the wheels with more traction.  However, in this style of AWD system, a failed drive shaft or similar disconnection prior to the brakes often results in drive power being lost to the disconnected component. The consequence of this loss is the inability to maintain speed with surrounding traffic which increases the risks of collisions and injuries to the vehicle occupants. The Subject Vehicles are built upon a platform that was designed primarily as Front Wheel Drive (FWD). The SH-AWD system functions more as a performance enhancement feature rather than a stability feature. Even if the SH-AWD is nonoperational, the vehicles retain full mobility via FWD. In addition, the Vehicle Stability Assist (VSA) remains functional, ensuring directional stability through traditional engine and brake-based traction control. Although the condition raised by the Petitioner may degrade the vehicle’s performance characteristics, there is insufficient information to indicate a potential unreasonable safety risk. ODI reviewed 62 Vehicle Owner Questionnaires (VOQs) and several EWR Field Reports alleging the loss of SH-AWD and its impact on the driving dynamics of the subject vehicles. During its analysis, ODI determined that the failure is localized to the mechanical interface between the FWD transaxle and the PTU. Specifically, the failure is the shearing or stripping of the interfacing splined shafts between the FWD transaxle and the PTU, resulting in a permanent loss of torque transfer to the rear of the vehicle. Upon reviewing the technical details of SH-AWD, ODI has found that this failure does not result in any loss of motive power or lead to a loss of vehicle control. Several complaints indicated that the operators were unaware of the mechanical fault until encountering a low friction surface or the condition was identified by a technician during routine maintenance. The SH-AWD system lacks any form of direct feedback for monitoring real time torque transfer to the rear wheels. Therefore, the system will continue to display information indicating power is being supplied to the rear wheels even when power is actually only supplied to the front wheels. ODI’s review did not identify sufficient evidence to indicate that the misinformation has presented a safety issue in the field. ODI did not identify any reports of loss of motive power or vehicle control that could be attributed to the loss of SH-AWD. ODI is not aware of any crashes involving the Subject Vehicles that resulted from the loss of SH-AWD. After thoroughly assessing the material submitted by the Petitioner, consumer complaint information in NHTSA’s databases, and other relevant information already in possession of the Agency, NHTSA has not found sufficient evidence to indicate that the loss of AWD as alleged by the Petitioner is likely to present a safety related defect that would warrant a formal investigation. After full consideration of the available information, and in view of NHTSA’s enforcement priorities, the Petition is denied.  A denial report will be posted in the Federal Register.  The closing of the petition does not constitute a finding by NHTSA that a safety related defect does not exist, and the agency reserves the right to take additional action if warranted by future circumstances.  The Petition can be viewed at NHTSA.gov under ODI Number 11712885.

Power Train:transfer Case (4-WHEEL Drive)

The Office of Defects Investigation (ODI) has completed its review of a Petition dated January 9, 2026, requesting an investigation into the loss of the optional all-wheel drive capability in model year (MY) 2021-2023 Acura TLX and MY 2022-2023 Acura MDX vehicles. The Petition alleges failures in the interfacing splines between the front wheel drive transaxle and the rear wheel drive power take off unit. Failure of these splines prevents the transfer of drive power to the rear axle, making the vehicle front wheel drive only. The Petition further alleges that this failure reduces vehicle directional control. Most traditional AWD systems utilize mechanical and passive measures. These systems have the tendency to distribute torque along the path of least resistance, such as a wheel that has lost contact with the ground or is on a low friction surface such as ice. To compensate for this, many manufacturers use the brake system to redirect torque to the wheels with more traction.  However, in this style of AWD system, a failed drive shaft or similar disconnection prior to the brakes often results in drive power being lost to the disconnected component. The consequence of this loss is the inability to maintain speed with surrounding traffic which increases the risks of collisions and injuries to the vehicle occupants. The Subject Vehicles are built upon a platform that was designed primarily as Front Wheel Drive (FWD). The SH-AWD system functions more as a performance enhancement feature rather than a stability feature. Even if the SH-AWD is nonoperational, the vehicles retain full mobility via FWD. In addition, the Vehicle Stability Assist (VSA) remains functional, ensuring directional stability through traditional engine and brake-based traction control. Although the condition raised by the Petitioner may degrade the vehicle’s performance characteristics, there is insufficient information to indicate a potential unreasonable safety risk. ODI reviewed 62 Vehicle Owner Questionnaires (VOQs) and several EWR Field Reports alleging the loss of SH-AWD and its impact on the driving dynamics of the subject vehicles. During its analysis, ODI determined that the failure is localized to the mechanical interface between the FWD transaxle and the PTU. Specifically, the failure is the shearing or stripping of the interfacing splined shafts between the FWD transaxle and the PTU, resulting in a permanent loss of torque transfer to the rear of the vehicle. Upon reviewing the technical details of SH-AWD, ODI has found that this failure does not result in any loss of motive power or lead to a loss of vehicle control. Several complaints indicated that the operators were unaware of the mechanical fault until encountering a low friction surface or the condition was identified by a technician during routine maintenance. The SH-AWD system lacks any form of direct feedback for monitoring real time torque transfer to the rear wheels. Therefore, the system will continue to display information indicating power is being supplied to the rear wheels even when power is actually only supplied to the front wheels. ODI’s review did not identify sufficient evidence to indicate that the misinformation has presented a safety issue in the field. ODI did not identify any reports of loss of motive power or vehicle control that could be attributed to the loss of SH-AWD. ODI is not aware of any crashes involving the Subject Vehicles that resulted from the loss of SH-AWD. After thoroughly assessing the material submitted by the Petitioner, consumer complaint information in NHTSA’s databases, and other relevant information already in possession of the Agency, NHTSA has not found sufficient evidence to indicate that the loss of AWD as alleged by the Petitioner is likely to present a safety related defect that would warrant a formal investigation. After full consideration of the available information, and in view of NHTSA’s enforcement priorities, the Petition is denied.  A denial report will be posted in the Federal Register.  The closing of the petition does not constitute a finding by NHTSA that a safety related defect does not exist, and the agency reserves the right to take additional action if warranted by future circumstances.  The Petition can be viewed at NHTSA.gov under ODI Number 11712885.

EA25004 · No Restart After Auto Start/stop Engages

Opened Mar 26, 2025 · No close date supplied

Status: open (inferred from source dates) · Engine And Engine Cooling:engine; Engine And Engine Cooling:engine:crank/camshaft Position Sensor; Engine And Engine Cooling:engine:engine Control Module (ecu/ecm):software; Engine And Engine Cooling:engine:hard Parts Internal/mechanical

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.

Additional source detail variants (4)

Engine And Engine Cooling:engine:crank/camshaft Position Sensor

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.

Engine And Engine Cooling:engine:engine Control Module (ecu/ecm):software

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.

Engine And Engine Cooling:engine:hard Parts Internal/mechanical

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.

Engine And Engine Cooling:engine

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.