Cadillac XT5 power steering loss problems

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 Oct 16, 2026 · Electrical, Engine · AR

Sudden Engine Shutdown and Loss of Steering Assistance in Traffic — 2021 Cadillac XT5 While operating our 2021 Cadillac XT5 in traffic, the vehicle suddenly and unexpectedly stopped running. The engine shut down, the instrument panel went dark except for a warning stating "Low Battery," and steering locked up. The emergency flashers would not work but blue-tooth did. The AC was working fine until shutdown but has not worked since. The car is still in the Cadillac dealership with no reasons given for the shutdown. The vehicle would not restart and was left immobilized in the middle of traffic, creating a serious risk of a collision. The "Low Battery" warning appeared only after the engine had stopped. There was no indication of a low-battery warning before the shutdown. A check of the vehicle's VIN showed no outstanding safety recalls. We are concerned that an electrical, engine-control, or power-distribution malfunction caused the sudden shutdown and loss of steering assistance. The exact cause has not yet been established. We request that the federal safety agency review this incident as a potential vehicle safety defect because an unexpected shutdown and loss of steering assistance in moving traffic creates a substantial risk to occupants and other motorists.

Filed Jan 23, 2026 · Engine, Steering · MI

To Whom It May Concern,I am writing to formally report a safety concern involving my 2018 Cadillac XT5, VIN [XXX] . Recently, my vehicle displayed a “Steering Assist Reduced” message on the dashboard while driving. This warning significantly increases the physical effort required to steer the vehicle, especially at low speeds, and I believe it presents a genuine safety hazard.Upon taking the vehicle to an authorized Cadillac dealership, I was informed that the vehicle had stored diagnostic trouble code P0128 (Engine Coolant Temperature Below Thermostat Regulating Temperature). The dealer explained that a malfunctioning thermostat caused the steering assist reduction message to appear. However, at no point did the vehicle illuminate a Check Engine Light, despite the presence of an emissions‑related fault code.I am concerned for several reasons:A critical engine fault (P0128) did not trigger a Check Engine Light, leaving me unaware of any underlying issue. The vehicle reduced power steering assist as a result of an unrelated thermostat malfunction, creating a sudden and unexpected increase in steering effort. This behavior poses a safety risk, particularly in situations requiring quick steering response or low‑speed maneuvering.Cadillac has issued Service Bulletin 17NA158, which acknowledges that thermostat or coolant‑temperature‑related issues can trigger steering assist warnings. This suggests the manufacturer is aware of the problem, yet no recall or corrective action has been issued.Given that steering assist reduction directly affects vehicle control, I believe this issue warrants investigation. A driver should not lose steering assist because of a thermostat fault, nor should a vehicle fail to illuminate a Check Engine Light when a diagnostic code is present.I respectfully request that the federal safety agency review this matter to determine whether a safety‑related defect exists in the 2018 Cadillac XT5 and similar GM vehicles. Sumitting this for my mother. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOI

Filed Aug 25, 2025 · Steering · TX

2018 xt5 code p128 steering assist is reduced drive with care its only has 37.282 miles on it steering got hard to control

Filed May 16, 2025 · Steering · 78,146 miles · FL

The contact owns a 2017 Cadillac XT5. The contact stated that while her husband was driving at approximately 50 MPH, the vehicle lost power steering functionality. The contact stated that the power steering assist message was displayed. The vehicle was taken to the local dealer where it was diagnosed and determined that the power steering assist had failed. The contact was informed that the part was on backorder. The vehicle was not diagnosed or repaired. The manufacturer was contacted. The failure mileage was approximately 78,146.

Filed Oct 9, 2024 · Engine · TX

This model Cadillac XT5 has early failures of engine cooling systems thermostats. The thermostat sticks open causing lower engine temperatures and higher emissions. The first sign you have an issue is a reduced power steering assist message on the instrument display. The engine control module stores a p0128 code as current. Continue driving the vehicle the ECM will shut off AC compressor engagement, so no AC. The next thing that happens is you lose temperature gauge. So you are now driving vehicle with reduced power steering assist, no AC and no way of knowing if the engine is overheating. This is a known issue with the refer to GM bulletin # 17-NA-158 posted May 2017. There has been a such a demand for this thermostat, that parts back orders are common. The volume of failures should be addressed as a recall including refunds to owners who have had to pay for this repair. The fact that a colder running engine typically runs richer based on ECM programming, causes higher emissions. GM hasn’t been helping people with this repair for out of warranty vehicles. Our 2017 XT5 failed at 38,000 miles. Cadillac only offered to pay 30% of the repair leaving a balance of $585.00! This was all because GM’s failed part.

Filed Dec 30, 2023 · Steering · FL

Message Displayed on 2017 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 2019 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 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 Oct 24, 2023 · Engine, Steering · LA

While traveling home to Louisiana from a vacation, I noticed the engine temperature what stuck on Cold. We also were experiencing loss of power steering, and loss of AC in the car. We stopped at AutoZone in Destin, FL where they completed their FixFinder which reported the thermostat needed to be replaced, being it was stuck in the open position and wasn't properly gauging the engine temperature. Some of the engine fluids were extremely low due to overcompensation because of the thermometer issue. Seeing as we were traveling and not near our local mechanic or dealership, we called around to various auto shops to see who could fit us in same day. The only available shop, without having to spend an additional night in FL, was Pep Boys in Fort Walton, FL. They also let us know they did not have the thermostat compatible with my engine in stock, so that would need to be purchased at AutoZone if we wanted the car fixed same day; which is what I did. While we were at Pep Boys, there was another Cadillac xt5 there for repairs to their AC. It turned out, they were having the exact same issue I was having, but it hadn't escalated to the power steering yet. The mechanic googled the two issues and found there are known issues with the engine thermostat in this make/model, but there has never been a recall issued for it. Now Cadillac is refusing to reimburse me for the repairs because I was still within my Powertrain warranty (under 73k miles) but because we were in a hurry to get home from vacation to get back to work, we did not take the car to a GMC dealership, so the Powertrain warranty is apparently useless here. My extended warranty is also useless because the Powertrain warranty is still in effect.

Filed Mar 8, 2023 · Electrical, Steering · AR

The contact owns a 2018 Cadillac XT5. The contact stated that while driving at various speeds, the steering power reduced warning message was displayed. The manufacturer was notified of the failure and referred her to the local dealer for assistance. The contact was also informed that there were no recalls on the vehicle. The vehicle was not repaired. The contact had not experienced a power steering failure in spite of the frequent illumination of the message being displayed. The failure mileage was unknown.