⌘K
Federal filingsHome›Recalls›Investigations› PE25015
NHTSA defect investigation · Preliminary Evaluation

Acura preliminary evaluation PE25015

Loss of braking force. NHTSA’s Office of Defects Investigation opened this preliminary evaluation about the master cylinder on 2 model years (2019–2020). Opened Oct 23, 2025, closed May 21, 2026 after 7 months. It led to safety recall 25V859000. became a recall

What NHTSA says

Source: Office of Defects Investigation, as filed

On October 23, 2025, the Office of Defects Investigation (ODI) opened Preliminary Evaluation PE25015 after receiving complaints concerning a loss of brake assist in 2019-2020 MY Acura ILX vehicles. These complainants alleged master cylinder failures resulting in soft pedal feel or the brake pedal intermittently going to the floor. These failures could result in extended braking distance increasing the risk of a crash. Honda found that residual plasticizer in the brake reservoir hose could contaminate the brake fluid. This contaminated brake fluid was then absorbed by the secondary cup seal, causing it to swell. Engine heat during operation could further expand the swollen seal, allowing brake fluid to pass. Brake fluid bypassing the master cylinder cup seals can reduce brake-pedal firmness and increase stopping distance. On April 08, 2026, Honda filed Recall 25V-859, recalling all 2016-2020 MY Acura ILX vehicles produced from October 9, 2014, to January 29, 2020. Under the recall, the dealer will replace the brake master cylinder with redesigned inner cup seals made of a different material, providing improved sealing capability. In view of Honda filing Recall 25V-859 addressing the subject of this investigation, ODI is closing this Preliminary Evaluation. NHTSA reserves the right to take additional action if warranted by future circumstances. To review the ODI reports cited in the Closing Resume ODI Report Identification Number document, go to NHTSA.gov.

Stage Preliminary Evaluation — NHTSA works to complete one within eight months Opened Oct 23, 2025 Closed May 21, 2026 Manufacturer Honda (American Honda Motor Co.) Components Service Brakes, Hydraulic › Foundation Components › Master Cylinder Resulting recall 25V859000

A Preliminary Evaluation is the first formal stage: NHTSA has decided the complaints and other information it screened are worth a closer look, and asks the manufacturer for its own data on the condition. The summary is the agency’s own text from its investigation file, unedited; the resumes carrying the full reasoning are linked below.

The paperwork NHTSA filed

Source: every document on this action, at nhtsa.gov
DocumentCodeFiledAt NHTSA
Opening resumeINOA2025PDF
Closing resumeINCLA2025PDF
Information request to the manufacturerINIM2025PDF
Manufacturer's response — dataINRD202537 files 12345678910111213141516171819202122232425262728293031323334353637

40 of 64 documents shown; the rest are under this number at nhtsa.gov.

These are NHTSA’s own files, served from the agency’s site — the resumes are what ODI wrote when it opened and closed the action, and the rest is the correspondence behind them, including what the manufacturer sent when the agency asked. They are linked, not copied: where a document names the people who wrote in, that redaction is the agency’s to make and its copy is the one you should read.

What owners had already reported

Source: complaints on file the day it opened

When NHTSA opened this on Oct 23, 2025, owners had filed 42 complaints with the agency about the model years above, of which 6 named the service brakes NHTSA went on to investigate. Owner complaints are the agency’s main early signal: ODI screens them, and a Preliminary Evaluation is usually where a pattern in them ends up.

This is what the complaint file held on that date, not a claim about which reports prompted the investigation — NHTSA’s complaint records carry no investigation number, so nobody can make that link from the data alone. The opening resume linked above names the reports ODI itself cited. Complaint records on this site begin with 2016.

What this means for an owner

Source: and what happens next

An 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 became a recall. The campaign page carries the manufacturer’s filed defect, risk and remedy, the build window and every model year covered; whether one specific vehicle is included is settled by VIN at nhtsa.gov/recalls.

Model years it names

Source: as NHTSA filed them

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 Investigation

Is PE25015 a recall?

No — it is the investigation that led to one. Recall 25V859000 is the campaign; its page carries the remedy.

Is PE25015 still open?

No. It closed on May 21, 2026 and led to recall 25V859000.

Which vehicles does PE25015 cover?

NHTSA opened it on 2 model years: 2020 Acura ILX, 2019 Acura ILX. That is the scope of the inquiry, not a list of affected vehicles; a recall, if one follows, defines its own population by VIN.