Cadillac CTS check engine light comes on

Filed Oct 20, 2026 · Brakes · OR

Component Affected: SERVICE BRAKES Description of Safety Defect & Incidents: Experienced a recurring, systemic mechanical failure within its camshaft-driven brake vacuum assist system, creating an imminent crash hazard on public roadways. On two separate occasions while traveling at operational roadway speeds trying to slow down for an interchange, the vehicle suffered a sudden, catastrophic loss of power brake assistance. The brake pedal instantly became completely rigid, hard pedal, requiring maximum physical exertion to slow the vehicle and drastically extending the emergency stopping distance.Repair History & Manufacturer Involvement: The primary brake vacuum pump was initially replaced by an authorized Cadillac dealership in July 2023. Following that service, the "Brake Assist" warning lamp remained persistently illuminated. I called the dealership to ask how I can reset the warning and no one called me back, so I just lived with it. After driving only approximately 5,000 miles over 3 years, the system completely failed again, causing the second aforementioned on-road moving brake failures.The vehicle was towed back to the authorized Cadillac dealership on June 29, 2026, and has remained continuously out of service in their possession for nearly four months (113+ days) as of late October 2026. Dealership technicians have hit a diagnostic wall. They have repeatedly replaced parts, brake vacuum pump, vacuum sensor hose, brake booster twice during this single visit, and the brake master cylinder. Despite these component replacements, diagnostic fault codes remain active, check engine and brake warning lights remain illuminated, and power braking function cannot be reliably restored.The failure is so severe that the dealership has opened two concurrent General Motors Technical Assistance Center (TAC) cases, and a corporate GM Field Engineer was deployed to inspect the car, which recommended to replace master cylinder on 09/22/2026, no contact since, no loaner.

Filed Oct 6, 2026 · Airbags, Transmission · 143,145 miles · VA

The contact owns a 2015 Cadillac CTS. The contact stated that while driving, the air bag warning light and the check engine warning light illuminated, and the message "Service Vehicle Soon" was displayed. Additionally, the rear end of the vehicle made an abnormal roaring sound. The vehicle was taken to the dealer, where a multi-point inspection was performed. The dealer replaced the purge valve due to a leak, an oil change was performed, and the check engine warning light was reset. The vehicle was taken back to the dealer to be diagnose regarding the roaring sound coming from the rear of the vehicle. The dealer determined that the rear differential was leaking due to a pinion bearing failure and needed to be replaced. The contact associated the failures with the federal safety agency Campaign Numbers: 20V038000 (Power Train) and 26V329000 (Air Bags). The failure mileage was approximately 143,145.

Filed Oct 27, 2025 · Engine · 74,990 miles · TX

The contact owns a 2019 Cadillac CTS. The contact stated that while driving at 40 MPH, the check engine warning light illuminated. The vehicle was taken to an Auto Parts Store and was diagnosed with catalytic converter failure. The contact stated that upon cleaning the catalytic converter and driving for 50 miles, the warning light turned off. The vehicle was not repaired. The dealer and the manufacturer were not notified of the failure. The failure mileage was approximately 74,990.

Filed Sep 20, 2025 · Engine, Transmission · OK

I purchased this vehicle is certified preowned Cadillac and during the warranty time I had a transmission issue that was causing the transmission to jerk when shifting from 1st to 2nd gear and at highway speeds, it would start jerking nonstop. I took it to the dealer and as per a service bulletin, they flushed the transmission fluid and replaced the transmission fluid. This was only a temporary fix because 30,000 miles later the same issues started occurring again and have gotten worse to the point that you can smell the transmission clutches burning and the transmission overheating, possibly causing the number four piston rings to come apart, resulting in an engine replacement as well. I’ve had to replace engine as possible result, but the transmission problem is still there and it has also caused the check engine light to come on intermediately. This could result in a complete transmission failure, causing a vehicle to lose propulsion leading to a possible accident and injuries. This issue needs to be investigated and repairs or replacement made at the manufacturers expense.. This is a four-cylinder turbo engine and an eight speed automatic transmission. In my opinion, the transmission issue caused my engine failure. There should be investigated and an immediate recall issued.

Filed Jul 12, 2025 · Transmission · TX

I began hearing a “hum” when driving my vehicle and dismissed it thinking it was the type of low profile, no flat tires. After a getting new tires, brakes, brake pads, and control arms, we still heard the “hum” and it continued to get louder. We took the car to 4 different places where they all stated the rear differential is the problem. I never had a service engine light come on. We found out that there was a recall on this part for other Cadillac CTS vehicles but my VIN did not come up as one that has a recall. I have had my rear differential fluid serviced and changed right before 30K miles. I now have a little over 95K miles and am told there is a back order for this part due to how many other Cadillac CTS vehicles are having the same issue. This could make car lock up at any time while driving. I transport my grandchildren and elderly Mother in this vehicle regularly. We have been told that it will take over $6K to fix and since the part is on back order, it will be several months before it can be fixed. This is not only a dangerous and possibly deadly circumstance, but extremely inconvenient and expensive. This part needs to be recalled for all Cadillac CTS vehicles and the parts need to be available as soon as possible.

Filed Feb 28, 2025 · Electrical, Engine · NC

driving to work on very busy highway. The engine light and Service Battery charging system came on, then went to battery saver almost instantly. Radio cut off, heat cutt off and the Car cut off in the middle of the highway before I could safely get over. this caused me to fear for my life as the cars behind me barely had time to stop. a hair probably could not have fit between us. I did eventually safely get off the highway, had the car towed to a service center. There was 14 different codes.(low voltage, engine running lean, low voltage and more. battery was checked and was 95 %, Alternator fine. was told it was the ECM. After looking on google some sites say there is a recall for 2013 cts some say there is not. there are multiple complaints on this issue and it is not safe. I called Cadillac gave my vin number and was told there was not a recall. Cadillac/GMC really need to issue a recall before something tragic happens, as it almost was me. Thank God that it wasn't.

Filed May 27, 2024 · Fuel system · MI

Gas leaking from above gas tank took car in for service 5/6/24. they could not duplicate issue on 5/24 engine light comes on. On 5/26/24 code indicated fuel pump issue. Several months before all of this, I would notice a strong gas smell after driving

Filed Nov 21, 2023 · Engine · CO

Engine warning light on. Diagnosed by Mike Maroon Cadillac, Boulder Colorado as Po008 code Bank one engine timing off. Further diagnosed as faulty engine cam chain. Advised not to drive car. Car available for inspection. Not being driven. Safety put at risk by possible major engine failure during use. Problem confirmed by two other repair facilities. Engine warning light on for several months. Problem confirmed by Mike Maroon Cadillac, Boulder Colorado. Taken there at the request of Cadillac customer service phone 800 333 4223. Contact at Cadillac customer service Miguel ext 591 6218. Given case #[XXX] Vehicle inspected by Mike Maroon Cadillac at the request of Miguel at Cadillac customer service. Inspection done at owners expense. Cadillac customer service not returning calls. Owners contact # [XXX] Mike Maroon Cadillac contact, Dave 303 442 3160 R/o #[XXX] Do not have capability to upload files. Will fax upon request. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 3, 2023 · Acceleration, Brakes · OH

There have been a collection of other Vin numbers for this year make and model for the symptoms I have been experiencing since taking ownership in 2019. The vehicle will stall while running and randomly disable ALL WHEEL drive, Traction Control, ABS, and send Check engine light on causing me amdy son on infinite number of times to almost be hit In the middle of amd intersection, after a stop sign at low speeds, upon turning the wheels into or put of driveway, parking spaces and worst off at 60 mph on a freeway. This has resulted in multiple near accidents as the vehicle randomly disables itself. It occurs mostly after pressing the brakes to shift gears and almost always causes the vehicle to become inoperable for over an hour where it sits as there is no option to disable AWD or choose from FWD OR RWD. It happens in manual mode (or called performance mode) as well as automatic mode and has been occurring for 5 and a half years. I have been charged an exorbitant amount for supposed repairs from.dealers and mechanics who have claimed to fix it and I have severe autoimmune disease, a foot prosthetic, AND a minor child I have to transport to and from.school in the car. My issue and warning lights and symptoms mirror the recall of the Vin numbers the manufacturer has performed the recall repair on exactly and yet I have been sent from dealers who refuse to check the part that's defective which is I believe the hydrolic brake rod to the brake petal. The bold needs to be simply retorqued to the proper torque to fix the problem as it was either assembled improperly torqued and or can loosen over time resulting in dangerous and immediate and unexpected complete loss of power to the vehicle allowing people to slam into you at any time. I have had it towed numerous times after these incidents. All features, climate control, locks, entertainment, windows and everything functions when this happens. I have replaced batteries, brakes, oil changes etc. Unresolved.

Filed May 11, 2023 · Brakes · 130,000 miles · OH

The contact owns a 2012 Cadillac CTS. The contact stated that while driving at various speeds, the brake pedal was depressed and the AWD inadvertently deactivated, causing the vehicle to lose motive power. The service brake assist, check engine, traction control, ABS, and stabili-trak warning lights were illuminated. The vehicle was towed to two independent mechanics; however, no failure was found. The dealer was made aware of the failure but confirmed that there was no recall associated with the VIN. The vehicle was not repaired. The manufacturer was not made aware of the failure. The contact related the failure to the federal safety agency Campaign Number: 11V536000 (Service Brakes, Hydraulic) however, the VIN was not included in the recall. The failure mileage was approximately 130,000.