Audi Q5 check engine light comes on

Filed Sep 12, 2026 · Brakes, Driver assistance · VA

Brake Electronics Control Unit Failure (DTC U041800): Logged active diagnostic code U041800 (implausible signal in address 812C). Dealership records confirm no permanent remedy exists, with software patches delayed into Q3 2026, leaving active braking and electronic system faults unaddressed. Electrical Grid Collapse & Parasitic Battery Drain: Vehicle experienced exterior lights activating independently during sleep mode and cyclical 300mA to 2.0A parasitic draws. Required warranty replacement of the Central Electrical Control Module (J519), Low Voltage Power Distributor Module (J1282), and primary 12V battery (RO #AUCS214055). Powertrain & Transmission Engagement Failures: Experienced Check Engine Light cycling and a total failure to engage "Park" for 20 minutes. Scanned hard factory codes P187C00 (gear actuator 3 failure), P086900, and P270800, requiring ten consecutive distance sensor calibrations. Adaptive Cruise Control & Restraints Malfunctions: ACC fails to engage due to false occupant-detection logic errors, triggering phantom rear-seat belt warnings while driving solo and throwing error messages that compromise restraint safety architecture. Liftgate Architectural Failures: Rear trunk lid fails to open or latch fully due to software conflicts with the mobile key platform, causing the control unit to lose its calibrated position.

Filed Aug 17, 2026 · Acceleration, Body · MD · crash

I was pulling into (my usual) handicapped parking space, at a slow speed. As I approached the curb my brakes did NOT respond to stop my car. Not only did my brakes not respond, the car actually sped up - going up the curb and hitting the handicapped sign pole. The pole broke and stopped my vehicle! I was afraid my (out of control) vehicle would keep going through a store front - it did not. Folks gathered around- thinking I had put my foot on the gas . I DID NOT put my foot anywhere except on my BRAKES …which went ‘mushy’ . would not stop my vehicle. My research has found similar incidents reported by other drivers. I am NOT ALONE. Of course the dealership could not reproduce the incident. But they did suggest many other services for a car with 60,000 miles. The AUDI dealership took NO responsibility for the incident. There was a recall on the master cylinder that was supposedly handled before I took delivery of the vehicle in January 2019. Audi denied that anything was currently amiss with my master cylinder. There was a warning message when I tried to start my car about a week before. Because it made no sense - like your tires are low - I dismissed it as just a check engine light 🤷🏽‍♀️ I honestly can’t remember what that ‘odd’ warning said🤦🏽‍♀️ I’m not alone in reporting this - I’m almost afraid to drive my car😰

Filed Jul 31, 2026 · Brakes, Driver assistance · NY

On XXX at approximately 5:00 PM, my 2025 Audi Q5 (VIN: [XXX]) initiated an unprovoked forward collision warning and emergency braking intervention while I was traveling at approximately 57–58 mph on [XXX]. Road conditions were clear and dry. Weather was sunny. Adaptive Cruise Control was not activated. I was the sole occupant of the vehicle. A vehicle was making a lawful turn onto the roadway from a T-intersection. There was substantial distance between my vehicle and the turning vehicle. No collision risk existed and no evasive action was required. Despite this, the vehicle's forward collision system overrode my control and initiated emergency braking without cause. As a result of the sudden braking and the force of the seatbelt restraint during the event, I sustained abdominal pain and lower back pain that began immediately following the incident and persisted thereafter. This incident did not occur in isolation. Prior to this event, the vehicle had already exhibited a documented pattern of electronic and driver assistance system malfunctions, including intermittent check engine warnings, repeated false-positive driver assistance alerts, power liftgate malfunctions, sunroof malfunctions, and additional electronic irregularities. All of these concerns were reported to Audi Albany prior to the emergency braking event. Following a service visit, I was told nothing further could be done. The vehicle is currently at Audi Albany undergoing inspection at the request of Audi of America, including a review of the Event Data Recorder. I am filing this complaint to ensure the incident is part of the federal safety record. A driver assistance system that initiates emergency braking at highway speed without a valid hazard present, on a vehicle with a prior history of false-positive alerts, represents a safety defect that I believe warrants federal documentation and review. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 22, 2026 · Engine · 43,000 miles · TX

The contact owns a 2021 Audi Q5. The contact stated that while driving approximately 55 MPH, the vehicle lost motive power and the vehicle decelerated before the vehicle stalled. During the failure, the check engine, oil, and coolant warning lights were illuminated. The vehicle was later towed to the local dealer to be diagnosed. The dealer determined that the engine bearings had failed, causing catastrophic damage to the engine. The contact was advised that the engine needed to be replaced. The vehicle was not yet repaired. The contact was informed that the VIN was not included in the federal safety agency Campaign Number: 22V753000 (ENGINE AND ENGINE COOLING). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 43,000.

Filed Jun 17, 2026 · Engine · NC

Vehicle purchased new off the showroom floor with 22 miles, driven locally only and garage kept. At 270 miles, upon starting the vehicle the engine was shaking and idling rough exactly like a misfiring cylinder would. The check engine light immediately turned on and started flashing and the engined bogged down and stopped. The dealership towed it to their shop and witness the rough idle themselves. When diagnosing the fault, it was confirmed 3 cylinders were misfiring due to "catalytic converter sensor" that triggered the engine to misfire for "protection reasons". The dealership checked the distributor and spark plug wires with no issues found, ultimately they reset the code which immediately returned the engine to proper function and idling. They drove it for 60 miles confirming proper function. Their "theory" is possible bad gas could have been put in the engine prior to the dealership buying the vehicle?? We told the dealership that we have not even put gas in the vehicle ourselves yet thus no fault on us for this postulated issue.

Filed May 27, 2026 · Engine · CO

I purchased a new 2025 Audi Q5 Sportback on 4/13/2026. I brought my car home that day and then had to go to the hospital for surgery so didn't drive my car for two weeks. I get in my car after a couple of weeks and the engine light came on and didn't come off I took it into Audi on May 7th. Audi said I could pick up my car on Monday May 11th and said the car battery was charged and I should be good. I brought my car home and then didn't drive it again for a week. I got in my car again and the engine light came on again. I called Audi on the Thursday before Memorial day and was told I needed to bring this back in. I took it in on Tuesday, and was told this code is a known issue and Audi is putting a fix in place to update the modules. They provided me the attached from Audi. If this is a known issue, I feel this should have been provided to me about this before buying the car. I was also told to continue to drive the car and with the light on. How dangerous is that to drive a car with the engine light and ignore it. If something is seriously wrong, I won't know cause I am told to ignore. I would like to know how to return this car as a lemon has this was a known issue and they don't know when the fix will be in place. I am asking for assistance on how to proceed with Audi. I have read several reviews on line with others that have experienced the same issues over a year ago. Thank you !

Filed Apr 29, 2026 · Driver assistance, Electrical · TX

I am reporting a safety-related defect involving my 2025 Audi vehicle. Shortly after leasing the vehicle in 09/2025, I experienced electrical and system malfunctions while driving, including warning lights, intermittent adaptive cruise control malfunctions, erratic acceleration, sputtering, and sudden braking without warning. These issues occurred during normal driving and raised safety concerns. On 11/03/2025, the vehicle failed to start and required multiple jump starts, displaying multiple system errors including a check engine light and malfunctioning displays. During a brief attempt to drive, the steering wheel began vibrating, additional warnings appeared, and the vehicle behaved as if on rough terrain despite normal pavement. The vehicle was towed to the dealership on 11/04/2025. While there, Audi’s Technical Assistance Center (TAC) and engineers were involved, and I was informed that internal technical guidance was issued related to this issue, indicating it may not be isolated. After more than two weeks, I was told the vehicle was repaired. On 11/19/2025, immediately after pickup, it malfunctioned again at highway speed. During lane changes, the vehicle resisted steering input and attempted to keep me in the lane despite signaling, creating a loss-of-control situation that required abrupt correction. A rear crash assist malfunction warning also appeared. I returned the vehicle the same day. Although it may start and run, I do not believe it is safe to operate due to the prior loss-of-control event and continued system instability. I have been asked to drive it again to reproduce the issue, which I do not feel is safe. This may involve a defect in driver assistance and electronic control systems.

Filed Apr 27, 2026 · Engine · CA

I was driving home from the farmers market with my two young kids. I was turning left at a busy intersection when the engine died and an engine warning flashed on the dash (I don't recall the exact message; it sounded catastrophic). There were no "check engine" or any other warning messages prior to the incident. I was able to restart the car immediately and give it a lot of gas to get out of the intersection - thank goodness - but didn't feel it was safe to drive the full 1 mile home, as there are several inopportune locations for an engine to die along the route, so I parked it in a residential neighborhood and walked home with my kids. My instinct there seems correct as it would not start again thereafter. I got it towed on the Monday and the mechanic called me to tell me that a piston had broken off in the engine and there is complete engine failure. I've attached a photo he took. This is a car we've had for 5 months with only 47,000 miles on it, regular service according to Carfax, and full/clean oil. No error messages or warnings prior. It was really scary to be in a busy intersection with a dead engine and young kids in the car.

Filed Apr 18, 2026 · Engine · MA

A failed (frozen) Turbocharger Wastegate Actuator. An engine warning light came on and engine had less power. It had to be replaced. There was a settled law suit for the same issue covering this item in previous vehicles settled in 2025.

Filed Mar 21, 2026 · Engine · CA

I am filing a safety complaint regarding a progressive engine defect. Beginning as early as 2019 (approximately 84,000 miles), I repeatedly reported excessive oil consumption and related engine concerns to authorized Audi dealerships. These complaints continued over several years. At no point was I informed that these symptoms could be associated with a known defect pattern or progressive engine failure. The condition has now escalated to a severe engine malfunction. The vehicle began exhibiting engine misfires, flashing check engine light, EPC warning, and unstable operation. The dealership confirmed misfire fault codes and oil contamination affecting the ignition system. Engine replacement was initially recommended. Excessive oil consumption leading to internal contamination and misfires presents a significant safety hazard. Loss of engine power or sudden failure while driving can create dangerous conditions, particularly at highway speeds or in traffic. Despite the long history of reported symptoms, Audi of America has declined to provide assistance, citing only warranty status and failing to address the defect progression. The vehicle has now been inoperable at an Audi dealership for approximately 60 days (nearly two months), with no resolution. This situation raises concerns regarding a safety-related defect, failure to disclose a known issue, and a potential broader pattern affecting similar vehicles equipped with this engine. I am requesting that this issue be reviewed for potential defect investigation. The dealer provided diagnostic findings with Failure Codes via a temporary link that is no longer accessible. I am requesting a copy of the full report and will upload this (once received), along with other documentation.