Cadillac Lyriq Brake Investigation: What NHTSA Is Examining

NHTSA's Engineering Analysis EA26006, opened August 21, 2026, examines a possible loss of brake assist in the Cadillac Lyriq and other General Motors vehicles that share the eBoost brake system, an estimated 1,164,820 vehicles; it is an investigation, not a recall.

It started as Preliminary Evaluation PE24011, which NHTSA opened on April 11, 2024 and which named only the 2023 Lyriq. An engineering analysis is a deeper stage of an investigation. It is not a recall, and NHTSA's resume does not say it has found a defect.

What does NHTSA's resume describe?

The opening resume for EA26006 starts from complaints about brake assist on the 2023 Lyriq. NHTSA writes that the complaints allege a hard brake pedal, followed by a "Brake System Failure" message at start up or while driving.

General Motors gave NHTSA records of internal investigations into loss of brake assist caused by alleged spindle fractures inside the eBoost system. The resume says GM has stated that after a fracture, anti-lock brakes, stability control and traction control keep working until the vehicle comes to a complete stop. At that point brake assist and those three functions are lost, the vehicle sets a diagnostic trouble code and driver warnings appear, and its speed is limited.

The resume then reports allegations that do not fit GM's account. Since opening the preliminary evaluation, the resume says, the agency has kept receiving reports of lost brake assist, and some of them describe symptoms inconsistent with GM's account of a spindle failure. Those reports allege an immediate loss of brake assist, not one that comes after the vehicle has stopped. NHTSA writes that a sudden loss during braking could extend braking distance and raise the risk of a crash or injury. It says further analysis is needed to assess whether failures of the eBoost system lead to safety-related outcomes. The resume's problem description is one line: failure of the eBoost system causing loss of braking and steering assist functions.

The failure report summary on page 1 of the resume lists 227 incidents in NHTSA's own ODI column and 531 from the manufacturer. The total is 745 once duplicates received by the manufacturer are removed. Within that, the resume counts 22 crashes or fires (21 of them in the ODI column), 5 injury incidents and 6 injuries, with no fatalities. NHTSA's companion document, the list of ODI report identification numbers, gives 227 ODI report numbers.

Those counts belong to every subject vehicle together. They are reports and allegations in NHTSA's file, not confirmed failures, and the resume does not split them by model.

How did a Lyriq inquiry become an engineering analysis?

The preliminary evaluation resume adds two points about GM's response. GM told NHTSA that its assembly plants reached a "clean break point" for a new material in May 2023, and that it had developed an over-the-air update that cycles the brake booster at every start-up. NHTSA states that this software update was not conducted as a recall.

The EA26006 resume says the Office of Defects Investigation opened this stage to assess the safety-related consequences of a failed eBoost system. It also widens the scope to all GM vehicles that share the system. That is more depth and more vehicles, not a conclusion.

An engineering analysis can close without a recall. NHTSA closed an earlier GM one, EA20002 on seat belt anchor cables, on August 30, 2024. That closing resume says the closure is not a finding that no defect exists, and that the agency can act again. An engineering analysis can also lead to a recall. Nothing in the EA26006 resume describes a recall of the eBoost system, so which way this one goes is open.

Which vehicles does NHTSA list?

NHTSA's resume names the vehicles it knows to carry the eBoost system, then adds the Acura ZDX and Honda Prologue as peer vehicles that GM built in a joint venture with Honda. The table follows NHTSA's wording and reads its semicolon-separated list as one 2024-2026 run from the Enclave through the Acadia. The last column says what RideTruth's catalog holds, checked against its model-year pages.

For the Blazer EV and Equinox EV, RideTruth's catalog has only the Chevrolet Blazer and Equinox nameplates, and this post makes no claim about whether those pages include the electric versions. The Acura ZDX hub also carries the 2010-2013 ZDX, an earlier vehicle that is not part of NHTSA's list. RideTruth has a separate post on Buick Enclave complaints by model year and one on the Cadillac Optiq's window recall, neither of which concerns the eBoost system.

Lyriq complaint counts by model year

As of October 13, 2026, RideTruth's records hold 24 NHTSA complaints on the 2023 Lyriq and 114 on the 2024 Lyriq. The 2025 has 19, the 2026 has 7 and the 2027 has 0.

These are owner reports as filed. A year with more of them has not been shown to fail more often: the counts are not divided by Lyriqs sold, and the 2023 and 2024 have been on the road longer than the 2026 and 2027. RideTruth drops any complaint with a filing date in the future or earlier than January 1 of the year before the model year.

The category label for brake-system complaints in RideTruth's data is Brakes. Owners pick the system on NHTSA's form and may pick several, so the shares below overlap with other areas' shares.

On the 2023 Lyriq, Visibility & Lighting is the area named most often, in 10 of the 24 complaints, and Brakes is named in 4. On the 2024, Driver Assistance & Speed Control leads at 52. Electrical follows at 38, and Brakes is third at 27.

None of this shows that a complaint describes the failure NHTSA is examining. A Brakes complaint can be about pedal feel, a warning light, pads or any other brake component. NHTSA's 227 ODI incidents also cover all the subject vehicles, so RideTruth cannot say how many are Lyriq complaints or which ones.

Does the Lyriq have a brake recall?

As of October 13, 2026, RideTruth's recall lists show 7 campaigns for the 2023 Lyriq and 6 for the 2024, and one of them names a brake component: 24V589000, filed August 8, 2024. NHTSA's record for it says the anti-lock brake system may activate unexpectedly and release brake pressure, with a software update as the fix, and it does not mention the eBoost system. The other campaigns on those two lists name seat belts, wiring, a traction battery, the instrument cluster, a body control module, the front stabilizer bar, the touch screen and back-over prevention software. NHTSA's recall data can reach RideTruth about two weeks late, so a newer campaign may not be on the lists yet. A VIN search at NHTSA's recall lookup is the current check.

Your garage keeps a saved Lyriq and looks for new NHTSA recall campaigns on it whenever you open the page.