IllustrationTransfer Case has gone out. No longer getting power to the rear wheels as it is a AWD car. Problem has not been checked by the dealer yet. There were no warning lights on the dashboard when it went out.
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.
About this comparison →How this year compares
Owner complaints by model year
Compare all Tlx years →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
What owners actually said
68 reportsThe all wheel drive failed do to transfer case splines being sheered off between the transmission and transfer case. No warning lights are on to warn of the rear wheel tires not receiving power to them. I was not aware of this problem and this could have contributed to and accident, as I though the AWD was working, but it wasn't…
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The all wheel drive failed do to transfer case splines being sheered off between the transmission and transfer case. No warning lights are on to warn of the rear wheel tires not receiving power to them. I was not aware of this problem and this could have contributed to and accident, as I though the AWD was working, but it wasn't.
Transfer case needs replacing
My vehicle was performing as expected, but there was a smell of burning oil or rubber. When I took the car into the dealership the found that the transmission was slipping and the transfer box was failing. In the video they sent of the initial inspection there is obvious brown sludge leaking from the transmission. I was told tha…
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My vehicle was performing as expected, but there was a smell of burning oil or rubber. When I took the car into the dealership the found that the transmission was slipping and the transfer box was failing. In the video they sent of the initial inspection there is obvious brown sludge leaking from the transmission. I was told that a complete transmission and transfer case was required.
Driving towards the gas station, still at lows speeds while I was in the neighborhood so speed limit was 15mph. I can hear and feel the car struggle to move forward, about 2 minutes into the drive a hear a big TOON and check engine light is on for about a minute before going away. I filled gas and headed back home and I heard a …
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Driving towards the gas station, still at lows speeds while I was in the neighborhood so speed limit was 15mph. I can hear and feel the car struggle to move forward, about 2 minutes into the drive a hear a big TOON and check engine light is on for about a minute before going away. I filled gas and headed back home and I heard a larger TOON but this time all the warning light came up. These are all errors reported by the car at the same time - Vehicle Stability System - Hill Start Assist Problem - Addictive Cruise Control System Problem - Collision Mitigation Braking System Problem - Road Departure Mitigation System Problem - Emission System Problem - All Wheel Drive System Problem - Brake System Problem These are all errors that appeared on the Acura app - Emission System Problem - Vehicle Stability System - Electric Parking Brake Problem - Electric Power Steering Problem - Adaptive Cruise Control Problem
I am submitting this complaint regarding a sudden and premature transfer case failure on my 2021 Acura TLX Type S equipped with Acura’s Super Handling All-Wheel Drive (SH-AWD) system. The failure occurred during normal driving conditions and without prior warning indicators. Based on my experience and numerous similar reports fr…
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I am submitting this complaint regarding a sudden and premature transfer case failure on my 2021 Acura TLX Type S equipped with Acura’s Super Handling All-Wheel Drive (SH-AWD) system. The failure occurred during normal driving conditions and without prior warning indicators. Based on my experience and numerous similar reports from other owners of this vehicle, this appears to be an ongoing and systemic issue that warrants formal investigation and recall consideration. While accelerating under normal road conditions, I heard a loud and distinct “pop” noise from underneath the vehicle. The sound was abrupt and mechanical in nature, as if an internal drivetrain component had failed. Immediately following the noise, the vehicle’s driving characteristics changed noticeably. Although the car continued to move forward and there were no immediate warning lights illuminated on the dashboard, the drivetrain behavior was clearly altered. After the incident, the vehicle began operating as though the majority of drivetrain load was being directed to the front wheels. The vehicle now feels significantly front-heavy during acceleration and general driving. There is a distinct change in weight transfer and torque delivery that was not present prior to the failure. The balance that is characteristic of a rear-biased SH-AWD performance system is no longer present. There were no grinding sounds, fluid leaks, or vibration at the time of failure. There were also no warning messages, check engine lights, AWD system warnings, or drivetrain alerts displayed to notify me of any malfunction. The failure occurred suddenly and without notice.I respectfully request that NHTSA open a formal investigation into premature transfer case failures on 2021–2023 Acura TLX Type S vehicles equipped with SH-AWD. This issue should be evaluated for recall eligibility or mandated corrective action to ensure driver safety. Thank you for reviewing this complaint.
My car has suffered a well known issue in the 21-25 Acura TLX community. At 71,000 miles my transfer case splines stripped also with the transmission splines. Resulting in me having to pay out of pocket to replace both the transmission and transfer case. I’m really hoping Acura does a recall for this issue. I really like this ca…
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My car has suffered a well known issue in the 21-25 Acura TLX community. At 71,000 miles my transfer case splines stripped also with the transmission splines. Resulting in me having to pay out of pocket to replace both the transmission and transfer case. I’m really hoping Acura does a recall for this issue. I really like this car and don’t want to have to replace them again. Like I mentioned before. I’m in a Facebook tlx group and people are constantly posting about theirs blowing.
Adaptive Damper System error on dashboard. Took the car to the dealer and they confirmed two issues. Codes C1646-14 and C1647-14 indicating the stroke sensor has lower limit abnormality. Dealer recommended replacing both rear shocks due to over extension. Once shocks were replaced, codes returned. During further investigation, c…
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Adaptive Damper System error on dashboard. Took the car to the dealer and they confirmed two issues. Codes C1646-14 and C1647-14 indicating the stroke sensor has lower limit abnormality. Dealer recommended replacing both rear shocks due to over extension. Once shocks were replaced, codes returned. During further investigation, corrosion was found in the stroke sensor wiring harness. Harness is the root cause of the issue. Car is available at the dealer for inspection if necessary. From a safety perspective, if I continued to drive the car I could have experienced a malfunction in the braking system which could have led to brake failure, failure of safety features, or a car stall.
My gas tank is failing from the fuel seal, my safety is in danger since it throws a lot of gasoline, take the car to the dealer but they say it's not a factory problem
To Whom It May Concern: The purpose of my complaint is to bring to your attention reprehensible policies and misconduct displayed by the automaker, Acura, the premium subsidiary brand of the American Honda Motor Company. On 11/18/2025, I brought in my 2021 Acura TLX Tech w/SH-AWD in for a problem related to the brakes. The front…
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To Whom It May Concern: The purpose of my complaint is to bring to your attention reprehensible policies and misconduct displayed by the automaker, Acura, the premium subsidiary brand of the American Honda Motor Company. On 11/18/2025, I brought in my 2021 Acura TLX Tech w/SH-AWD in for a problem related to the brakes. The front brakes were and continue to make a jarring, very loud, high-pitched squeaking noise at low speeds. After 4 hours at Radley Acura of Falls Church, VA, the technician stated "could not duplicate" the concern. The problem persisted and I again returned on 12/18/2025 for the same issue. My vehicle has been at the dealership awaiting a response from Acura Client Relations on a claim that I submitted on 12/19/2025. Radley Acura diagnosed the issue as a well-known defect of 2021 TLX models, as evidenced by Acura's own service bulletin describing the very issue I continue to experience (and yet were unable to diagnose on 11/18). Radley Acura is stating that although my vehicle is 28,000+ miles UNDER the manufacturer's warranty, that by time, since purchase, it is outside the manufacturer's warranty by approximately 6 months. However, on 1/27/2025 (when my car was within manufacturer warranty and only had 17,215 miles on the odometer), I completed a lease buyout of my car. In addition, I paid to have it Acura Precision Certified. As part of this paid certification, Radley had my car for over a day to allegedly perform a 182-point inspection, and address a recall open for over a year (with a remedy from Acura - but allegedly no available repair parts to fix my car, until I requested to CPO my at the time of lease buyout). During their CPO inspection, the dealership failed to address the open service bulletin on the front brakes--a documented issue Acura has been aware of since before 2/15/2022, as established by their service bulletin. Now the dealership is stating the manufacturer's defect that they failed to address is $500 out of pocket expense.
Official recalls
426V332000 · 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
2DP26001 · 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.