2019 Cadillac XT5: check engine light

Filed Oct 26, 2026 · Engine, Steering · NM

My 2019 Cadillac XT5 has repeatedly shuddered at highway speeds since shortly after purchase on July 25, 2026. It occurs around 61–62 mph while maintaining speed before accelerating. The cause is UNKNOWN. The selling dealership evaluated the vehicle and performed a front-wheel alignment, but the shuddering persists. Its repair record states that technicians could not reproduce the shuddering during a test drive. A test drive with me was proposed to demonstrate when it occurs. The vehicle has also displayed a “Steering Assist Is Reduced—Drive With Care” warning and a check-engine light. The steering felt normal despite the warning; I am not claiming an actual loss of steering. The temperature gauge has remained on cold, and the air conditioning has malfunctioned. The exact date the steering warning first appeared is UNKNOWN. On October 21, 2026, another Chevrolet dealership documented diagnostic code P0128 and recommended thermostat/coolant-temperature-related repairs. Those repairs have not been performed. The manufacturer was contacted and declined repair assistance. Dealerships have inspected the vehicle; I am not aware of a separate inspection by the manufacturer. I am concerned about the persistent shuddering at highway speeds and the warning of potentially reduced steering assistance. The cause of the shuddering and its relationship, if any, to the other symptoms remain unconfirmed. I still have the vehicle. Repair records, diagnostic information, and photographs of warning messages are available.

Filed Jan 9, 2026 · Engine · 100,000 miles · NC

The contact owns a 2019 Cadillac XT5. The contact stated that while leaving the driveway, there was an abnormal sound coming from the vehicle. The contact stated that while driving at 65 MPH, there was an abnormally loud squeaking sound coming from the vehicle. The check engine warning light was illuminated. The contact thought that the catalytic converter had been stolen. The vehicle was taken to an independent mechanic who determined that the catalytic converter was severed at the connection point and cracked, and removed. The contact stated that coils were damaged, and the thermostat housing was cracked. The vehicle was repaired, but the failure recurred. The local dealer was contacted, who determined that the catalytic converter had been replaced, but the failure persisted. The dealer informed the contact that the parts were on backorder. The manufacturer was not contacted. The failure mileage was approximately 100,000. The VIN was not available.

Filed Mar 22, 2025 · Steering · TX

Steering assist disengaged, low power mode, no temperature read and check engine light. All occurred at 61k miles.

Filed Jan 8, 2024 · Engine · FL

Was driving the other day and the message steering assist reduced, AC fan was blowing but no A/C then engine light came on. Made appointment next day with my Cadillac local dealer and service writer said he knew what the problem was. After he plugged into my car, then into his computer it read - bad thermostat. Fortunately, mine was covered under the powertrain warranty, however, he said there were 4 other vehicles just like mine (XT5) in there for the same issue. This is a well known issue with Cadillac and for those of us who have a warranty that's good. Otherwise, it is $1,200 to fix!!! Ouch!! Not sure why Cadillac hasn't issued a recall on this problem and very disappointed in them for not doing so.

Filed Dec 30, 2023 · Steering · FL

Message Displayed on 2019 Cadillac XT-5 "Steering Assist is Reduced - Drive With Care". No check engine light, and no apparent loss of steering. Noted that Temperature Gauge and Air Conditioning ceased to work. Suspiciously, a 2017 Cadillac XT-5 that I also own, the identical displayed message came on, with identical same mechanical issue, and just learned that an acquaintance with a newer Chevy Blazer just experienced the identical issue also. All vehicles are equipped with OnStar. Coincidence, OR any possibility that GM or OnStar computers have been hacked into, as OnStar has ability to control various functions of vehicles. To correct the issue (possibly only temporary) was to remove the negative battery cable for a short time, and reattach.

Filed Jan 14, 2023 · Brakes, Electrical · NJ

Service stability track light came on. Brought to Mechanic hooked up to computer. No code shown. Mechanic says car is fine. Keep it off for 15 minutes and the computer will reset. Driving on the highway Emergency brake came on by itself and stopped the vehicle all caution lights lit up on on the dashboard. Service engine light came on brought it back to the mechanic again no codes shown drove it for three days has been running fine and on the fourth day vehicle will not start.

Filed Jun 19, 2019 · Lights, Visibility · 2 miles · TN

We bought xt5 on 12/04/18, on 02/19/19, brought in for transmission and check engine light. 06/10/19, brought in for routine maintenance and service. 06/16/19, on the way back from knoxville on freeway I-40, while it was raining hard, all lights inside and out and windshield wipers didn't work. Wipers were standing up right in front of driver and stop, never move back down. We were surrounded with high speed cars and trucks, and semis, in the rain and couldn't see the front with no wipers, and inside the car was pit black. We must drive for around a mile before getting to a next exit. Got off exit, call onstar for help, they said wait 90 minutes for tow truck and we must find our own transportation to get home, since it was sunday, no one was open at that time. We didn't know where we were so we waited out the rain, and drove slowly back in town, with wipers sticking up in front of driver, to meet up with sales rep. Tim marcum for help, he loan us a car to get home and came the next day, monday, to see jayson taylor, cadillac manager. We asked them to buy back the car since we are so scare now what would happen next time with the car. They suggested us calling gm directly. We did, and jayda, senior case manager said she would only pay for fixing but not buying back, unless something major happened, like transmission, engine, brakes,.. We told her that this was serious, we we were in danger of loosing our lives there, but obviously it was not serious to her, we said what if the same thing happened, on freeway, fast speeding cars and trucks, raining hard, but instead of no lights and now wipers, this time no brakes or sudden stop and engine not starting. What would happened? In 6 months period, 2 incidents already, the later is more serious than the first, we rather prevent problems than having to deal with it, what if the problems getting bigger or someone get hurt