Acura MDX Investigations

9 ODI actions on file.

• DPDP26001CLOSEDOpened 3/6/2026
  All wheel drive allegation
  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.

• PEPE25008OPENOpened 8/20/2025
  Engine failure
  ENGINE

  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.

• EAEA25004OPENOpened 3/26/2025
  No Restart After Auto Start/Stop Engages
  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.

• RQRQ24013CLOSEDOpened 11/8/2024
  Engine failure
  ENGINE

  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.

• EAEA21002OPENOpened 9/17/2021
  Desiccated Air Bag Inflator Rupture
  AIR BAGS:FRONTAL:DRIVER SIDE:INFLATOR MODULE

  From 2000 through 2017, Takata produced millions of air bag inflators using two types of phase-stabilized ammonium nitrate ("PSAN") propellant -- propellant 2004 and propellant 2004L. After prolonged exposure to high temperature cycles and humidity, inflators using propellant 2004 can degrade, causing the propellant to burn too quickly when ignited. The rapid burning can cause the inflator to rupture during deployment, potentially causing serious or even fatal injury to vehicle occupants. See 2016 Blomquist Report at www.nhtsa.gov/sites/nhtsa.gov/files/documents/expert_report-hrblomquist.pdf.Consequently, all frontal inflators using propellant 2004 that do not contain a "desiccant" (a substance that traps and holds moisture) in US vehicles are under recall. These "non-desiccated" inflators either have been or are required to be replaced.In some cases, the remedy part for these recalled inflators was, or will be, an inflator using either propellant 2004 or 2004L that does contain a desiccant. None of these "desiccated" remedy parts (which were installed in older model year vehicles) are currently under recall for a degradation concern. Certain subsets of desiccated PSAN inflators using propellant 2004 for use as original equipment, however, have been recalled for a degradation concern. All Takata inflators produced with propellant 2004L contain desiccant, and none of these desiccated inflators using propellant 2004L are under recall for a degradation concern. There have been no reported field ruptures in any non-recalled desiccated PSAN inflators.It is understood that desiccants fully saturate at some threshold, at which point any additional moisture will not be captured. This means the degradation process observed in non-desiccated inflators using propellant 2004 may also occur in non-recalled desiccated inflators using propellant 2004, assuming additional moisture enters the inflator and high temperature cycling occurs. Based on available information, desiccant saturation can occur within the first five years in the worst environments, and the time required for full saturation is affected by multiple factors. While no present safety risk has been identified, further work is needed to evaluate the future risk of non-recalled desiccated inflators using propellant 2004.Three entities -- Takata (now known as TK Global), the Independent Testing Coalition, and Exponent -- have been studying the long-term behavior of Takata desiccated PSAN inflators using propellant 2004L (as well as 2004) in the presence of moisture and temperature cycling. The research efforts, which include development of predictive modeling techniques and field sample analysis, are ongoing. To date, none of the researchers have identified field evidence showing that propellant 2004L is undergoing a degradation process that leads to aggressive deployment and potential rupture. However, the time in service of such inflators remains short compared to that of the inflators using propellant 2004. Further study is needed to assess the long-term safety of desiccated inflators using propellant 2004L.The Office of Defects Investigation is opening this investigation to examine whether a safety defect related to propellant degradation exists in non-recalled desiccated PSAN frontal inflators manufactured by Takata. This investigation will require extensive information on Takata production processes and surveys of inflators in the field. Lists of recall actions that may have used desiccated PSAN inflators as remedy parts, as well as the makes and models originally manufactured with them, is available with the downloadable version of this document (see nhtsa.gov/recalls?nhtsaId=EA21002 -- note this information is subject to change/revision as the investigation proceeds). This investigation does not supersede EA15-001, which remains open.

• EAEA15001RECALLOpened 2/24/2015
  Air Bag Inflator Rupture
  AIR BAGS:FRONTAL

  The Office of Defects Investigation (ODI) opened PE14-016 in June 2014 based on six inflator rupture incidents involving consumer owned vehicles produced by five vehicle manufacturers.All six vehicles were operated in Florida or Puerto Rico at the time of the rupture and for the majority of their service life, and were equipped with inflators produced by Takata, a tier-one supplier of automotive air bag systems.During the course of PE14-016, ODI determined that five additional vehicle manufacturers used inflators of a similar design and vintage also supplied by Takata. No evidence of field failures was found in vehicles produced by these five additional manufacturers.Nonetheless, at ODI's insistence, all 10 vehicle manufacturers initiated a regional recall within approximately two weeks of the opening of the investigation.The regions recalled initially included Florida, Puerto Rico, Hawaii, and the U.S. Virgin Islands, areas with high absolute humidity and climatic conditions believed to be a significant factor in the inflator ruptures.As part of the recall actions, inflators removed from remedied vehicles are to be returned to Takata for testing.Takata's initial test results on passenger inflators from remedied vehicles indicated a much higher than anticipated rupture frequency for inflators returned from Florida.Accordingly ODI requested all 10 manufacturers expand the regional recalls for passenger inflators to include other geographic areas where high absolute humidity conditions exist, including the Gulf States and other coastal areas.Takata's testing of the passenger inflators to date continues to indicate this geographic area as having the highest risk, with no ruptures occurring from inflators returned from outside the expanded recall regions.During PE14-016 four additional passenger inflator field events occurred, all in vehicles from the same expanded geographic region.Also during PE14-016 four additional driver inflator field events occurred including two in vehicles from regions not known for high absolute humidity, specifically California and North Carolina.Accordingly, ODI requested all five of the affected vehicle manufacturers currently using the subject Takata driver inflators expand to nationwide recalls.Significantly, neither of the affected vehicle manufacturers or Takata provided any explanation to account for these two driver air bag inflator ruptures outside the area of high absolute humidity.Takata testing of returned driver inflators indicates a lower rupture frequency as compared to passenger inflator testing.All test ruptures reported by Takata to date have occurred on inflators returned from high absolute humidity areas.The investigation now includes all manufacturers and vehicles known to be affected at this time.ODI's investigation will focus on, among other things, root cause analysis, other potential defect consequences, identification of affected vehicles scope, and adequacy of the remedy.The five ODI reports cited above can be reviewed online at http://www-odi.nhtsa.dot.gov/owners/SearchNHTSAID under the following identification numbers: 10537899, 10568848, 10585224, 10605877, 10651492

• PEPE14016RECALLOpened 6/11/2014
  Air Bag Inflator Rupture
  AIR BAGS:FRONTAL

  The Office of Defects Investigation (ODI) opened PE14-016 in June 2014 based on six inflator rupture incidents involving consumer owned vehicles produced by five vehicle manufacturers.All six vehicles were operated in Florida or Puerto Rico at the time of the rupture and for the majority of their service life, and were equipped with inflators produced by Takata, a tier-one supplier of automotive air bag systems.During the course of PE14-016, ODI determined that five additional vehicle manufacturers used inflators of a similar design and vintage also supplied by Takata. No evidence of field failures was found in vehicles produced by these five additional manufacturers.Nonetheless, at ODI's insistence, all 10 vehicle manufacturers initiated a regional recall within approximately two weeks of the opening of the investigation.The regions recalled initially included Florida, Puerto Rico, Hawaii, and the U.S. Virgin Islands, areas with consistently high absolute humidity and climatic conditions believed to be a significant factor in the inflator ruptures.As part of the recall actions, inflators removed from remedied vehicles are to be returned to Takata for testing.Takata's initial test results on passenger inflators from remedied vehicles indicated a much higher than anticipated rupture frequency for inflators returned from Florida.Accordingly, ODI requested all 10 manufacturers expand the regional recalls for passenger inflators to include other geographic areas where high absolute humidity conditions exist, including the Gulf States and other coastal areas.Takata's testing of the passenger inflators to date continues to indicate this geographic area as having the highest risk, with no ruptures occurring from inflators returned from outside the expanded recall regions.During PE14-016, four additional passenger inflator field events occurred, all in vehicles from the same expanded geographic region.Also during PE14-016, four additional driver inflator field events occurred including two in vehicles from regions not known for high absolute humidity, specifically California and North Carolina.Accordingly, ODI requested all five of the affected vehicle manufacturers currently using the subject Takata driver inflators expand to nationwide recalls.Significantly, neither of the affected vehicle manufacturers or Takata provided any explanation to account for these two driver air bag inflator ruptures outside the area of high absolute humidity.Takata testing of returned driver inflators indicates a lower rupture frequency as compared to passenger inflator testing.All test ruptures reported by Takata to date have occurred on inflators returned from high absolute humidity areas.The PE is now closed/upgraded to an Engineering Evaluation (EA15-001) to include all manufacturersand vehicles known to be affected at this time.ODI's EA investigation will focus on, among other things, root cause analysis, other potential defect consequences, identification of affected vehicles scope, and adequacy of the remedy.The recalls related to this PE are: 14V343, 14V344, 14V348, 14V351, 14V353, 14V655, 14V700, 14V701, 14V752, 14V763, 14V770, 14V773, 14V787, 14V802 and 14V817.The number of vehicles affected are an estimate since some vehicles may have both the driver and passenger side inflators recalled. The five ODI reports cited above can be reviewed online at http://www-odi.nhtsa.dot.gov/owners/SearchNHTSAID under the following identification numbers: 10537899, 10568848, 10585224, 10605877, 10651492

• EAEA13002RECALLOpened 2/21/2013
  Vehicle Stability Assist Malfunction
  ELECTRONIC STABILITY CONTROL

  On March 14, 2013, American Honda Motor Co., Inc. (Honda) submitted a Defect Information Report to NHTSA identifying a defect in the Vehicle Stability Assist (VSA) system in approximately 183,576 model year (MY) 2005 Honda Pilot, Acura RL and MY 2005-2006 Acura MDX vehicles (NHTSA Recall No 13V-092).The population and failure counts provided pertain only to the MY 2005 Honda Pilots that were the subject of this investigation.Honda's recall addresses two conditions in the VSA system that could result in inappropriate brake activation.The first condition is related to a manufacturing concern with a capacitor in the VSA electronic control unit (ECU) circuit board.According to Honda, VSA systems with damaged capacitors may apply a small amount of braking force for a fraction of a second, when the brake pedal is not applied by the driver.If the driver does apply the brake pedal during a malfunction, the VSA system may employ the brake assist feature rapidly increasing braking force independent of the amount of pressure the driver applies to the brake pedal (releasing the brake pedal would end the brake assist activation in such events).The second condition applied to a portion of the MY 2005 Pilot vehicles manufactured at the Alabama assembly plant that may havebeen assembled without tightening one of the VSA system electrical ground connector fasteners to the proper torque.According to Honda, an improperly torqued fastener can result in increased electrical resistance in the VSA system, causing an incorrect signal to be sent to the VSA ECU, which may result in inappropriate braking while driving with no pedal application by the driver.The owners of all affected vehicles will be contacted by mail and asked to take their vehicle to a Honda or Acura dealer who will install a partial wiring harness containing a capacitor for the VSA modulator and, if necessary, inspect and tighten the affected electrical ground fastener.All work will be performed at no charge to the owner.ODI identified 106 incidents of inappropriate brake activation by the VSA system that appear to be related to the defect conditions addressed by Honda's recall.While many of the incidents reported experiencing significant unexpected braking while driving, none resulted in crashes or injuries.ODI reviewed a VOQ reporting a crash resulting in two fatalities that allegedly may have been related to the VSA conditions investigated in PE12-028 and EA13-002 (VOQ 10492170).After interviewing thecomplainant and reviewing evidence regarding the crash (e.g., police report and witness statements), ODI did not find sufficient evidence to determine that the crash was related to the VSA system.Regarding the 25 incidents of brake activations of short duration due to a yaw rate sensor malfunction, complainants indicate that typically the events are very brief and that the puling effect is mild.This investigation is closed.

• PEPE12026RECALLOpened 10/2/2012
  Ignition Interlock Failure - Rollaway
  ELECTRICAL SYSTEM:IGNITION

  On December 10, 2012, Honda Motor Company submitted a defect information report to NHTSA regarding ignition interlocks in approximately 576,117 model year MY) 2003 through 2004 Honda Pilot and Odyssey vehicles that are the subject of this investigation and 231,044 MY 2003 through 2006 Acura MDX vehicles (Recall No. 12V-573).Honda's report states that a design change to the ignition switch used in the recalled vehicles reduced the range of rotation for the ignition switch from 160 degrees in earlier designs to 125 degrees without a corresponding change to the ignition interlock blocking mechanism.The result was that excessive rotational force could damage a lever that would allow the driver to remove the ignition key that was in a position other than the Park position, which may allow the vehicle to roll away.ODI identified 176 complaints related to the alleged defect, including 48 roll away crashes.Threeof the incidents resulted in the following injuries to pedestrians:1) a broken foot and torn Achilles tendon; 2) a fractured fibula and crush injuries to a shin area; and 3) an incident requiring unspecified treatment at a hospital emergency room.This investigation is closed.The VOQs associated with this investigation are: 10486515, 10486393, 10486100, 10485010, 10482229, 10482091, 10481169, 10481105, 10481079, 10481027, 10480804, 10480648, 10480099, 10480009, 10479934, 10479695, 10479561, 10479517, 10479494, 10479484, 10479437, 10479421, 10479409, 10479343, 10478916, 10478876, 10478857, 10478845, 10478784, 10478776, 10478720, 10476767, 10473167, 10465590, 10463995, 10457825, 10452596, 10451185, 10448593, 10446962, 10440841, 10440040, 10439061, 10439033, 10438611, 10425909, 10403299, 10397920, 10395833, 10395298, 10379673, 10374724, 10365751, 10363501, 10361325, 10358480, 10355331, 10354680, 10354669, 10354390, 10353281, 10351899, 10351489, 10351240, 10349716, 10349612, 10348987, 10348955, 10348725, 10348579, 10348564, 10348429, 10348389, 10348268, 10348254, 10331474, 10325334, 10276072, 10179464.