Honda and Acura engineering analysis EA25004
No Restart After Auto Start/Stop Engages. NHTSA’s Office of Defects Investigation opened this engineering analysis about the crank/camshaft position sensor on 52 model years (2015–2025). Opened Mar 26, 2025 and still open — 18 months so far, against NHTSA’s goal of eighteen months for a engineering analysis. open
What NHTSA says
Source: Office of Defects Investigation, as filedOn June 3, 2022, the Office of Defects Investigation (ODI) opened Preliminary Evaluation PE22005 after the agency received VOQs and several �eld 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.
A Engineering Analysis is the deeper stage, usually upgraded from a Preliminary Evaluation: NHTSA tests, requests engineering documents and decides whether a safety defect exists. The summary is the agency’s own text from its investigation file, unedited; the opening and closing resumes with the full reasoning are on NHTSA’s site under this number.
What this means for an owner
Source: and what happens nextAn investigation is not a finding that a defect exists, and it puts no duty on anyone. NHTSA opens a Preliminary Evaluation when complaints and other reports suggest a condition worth asking the manufacturer about; it upgrades to an Engineering Analysis when the answers warrant testing; it closes either when it recommends a recall, when the manufacturer recalls on its own, or when no defect trend is found. The agency’s own goals are about four months for a petition, eight for a Preliminary Evaluation or a Recall Query and eighteen for an Engineering Analysis; many run longer.
This one is open. Nothing is owed on the vehicle today; if it becomes a recall, owners are written to and the repair is free. The moment to know is the day the campaign number appears — Recall Watch checks each VIN against every new NHTSA campaign and emails you when one lands, or take a free one-line alert by model year.
Model years it names
Source: as NHTSA filed themand 11 more on this site: 2020 Honda Pilot, 2019 Honda Pilot, 2018 Honda Pilot, 2017 Honda Pilot, 2016 Honda Pilot, 2025 Honda Ridgeline, 2024 Honda Ridgeline, 2023 Honda Ridgeline, 2022 Honda Ridgeline, 2021 Honda Ridgeline, 2020 Honda Ridgeline.
Also named on model years this site has no page for: 2015 Acura TLX.
A vehicle page’s investigation list carries the same action; a name here is the scope NHTSA opened, not a list of affected VINs.
Common questions
Source: NHTSA Office of Defects InvestigationIs EA25004 a recall?
No. A engineering analysis is NHTSA asking questions, not a recall. A safety recall carries an NHTSA campaign number and a duty to repair for free; this one has not produced one. Whether one particular vehicle has an open recall is a VIN question at nhtsa.gov/recalls.
Is EA25004 still open?
Yes, as of NHTSA’s latest file: opened Mar 26, 2025, 18 months ago.
Which vehicles does EA25004 cover?
NHTSA opened it on 52 model years: 2025 Acura MDX, 2024 Acura MDX, 2023 Acura MDX, 2022 Acura MDX, 2021 Acura MDX, 2020 Acura MDX and more. That is the scope of the inquiry, not a list of affected vehicles; a recall, if one follows, defines its own population by VIN.