2018 Buick Lacrosse problems

Filed Nov 11, 2025 · Electrical, Fuel system · SC

When I get to a stop sign, and a stop light, when trying to accelerate after a complete stop, the car would struggle to accelerate to go forward. Where the shifting gears would start blinking, and the warning lights (engine power reduced, engine light, and the traction safety collision light) would display itself making it misfire and impossible to even go forward while pressing the gas pedal. It put me and other drivers at a safety risk because it would roll backwards after taking my foot off the breaks to accelerate where it would almost hit drivers behind me at the stops as well as them almost mistakingly hitting me in the back when my break lights stop reflecting when trying to accelerate at stop lights with traffic. I have had it diagnosed with the recall codes N20231344O GM # 20V668000 the federal safety agency # 18V576000 18V358000 But the dealships are saying there aren't any recall for the vehicle. This issues is ongoing.

Filed Sep 22, 2025 · Acceleration, Engine · 26,600 miles · MA

The contact owns a 2018 Buick LaCrosse. The contact stated the hand controls were not working properly. While driving, the accelerator pedal was depressed, but the vehicle failed to respond. The engine power reduced message was displayed, and the check engine warning light was illuminated. After several attempts, the codes were reset, and the vehicle worked as designed. The contact linked the failure to the Special Coverage Campaign: N182188250. The vehicle was taken to an independent mechanic who disconnected the hand controls and informed the contact that the controls were operating as designed. The vehicle was taken to the local dealer, where it was diagnosed, and determined that the accelerator pedal position sensor needed to be replaced. The vehicle was repaired, but the failure recurred. While driving at 55 MPH, the vehicle lost motive power and decelerated to 15 MPH. The message “Engine Power Reduced” was displayed, and the check engine warning light was illuminated. The vehicle was taken back to the same local dealer, where it was diagnosed and determined that the accelerator pedal position sensor needed to be replaced; however, the failure persisted. The manufacturer was contacted, and referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was approximately 26,600.

Filed Nov 5, 2024 · Engine · NC

The 3.6 liter engine in my 2018 Buick Lacrosse Avenir only has 53,939 when we experienced a thermostat failure. The engine temperature was dead cold, and the dual electric fans were running non-stop. When I scanned the trouble code, I found PO128 which points to a faulty thermostat. Because the thermostat is buried under the intake manifold, we had the local Buick dealership replace it at a cost of over $800.00. I don't feel that a car with so few miles should be experiencing a thermostat failure. But this seems to be a common problem with the GM 3.6 liter motor according to a number of Buick forums that I read after the problem occurred.

Filed Jun 11, 2024 · Brakes, Fuel system · 161,188 miles · TX

The contact owns a 2018 Buick Lacrosse. The contact stated while driving at an undisclosed speed, the vehicle hesitated to accelerate while the accelerator pedal was depressed. The contact pulled over and checked underneath the vehicle. The contact discovered that the START/STOP accumulator endcap bolt had detached, causing transmission fluid to leak onto the ground. The vehicle was towed to the residence. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The contact stated that in 2021, he detected an abnormal fuel odor coming through the air vents while driving. The brake pedal also stuck while depressed, and the rear brake pads needed to be replaced frequently. The contact stated that the vehicle was taken to an unknown dealer in 2021 for the fuel odor, and an unknown fuel system part was replaced. The contact related the failures to the federal safety agency Campaign Numbers: 20V668000 (Power Train), 18V358000 (Fuel System, Gasoline), and 18V576000 (Service Brakes, Hydraulic); however, the VIN was not included in the recalls. The manufacturer was made aware of the failure but informed the contact that there was no recall associated with the VIN. The failure mileage was 161,188.

Filed Dec 23, 2023 · Engine · FL

Thermostat failure at 56,000 miles.

Filed Nov 9, 2023 · Electrical · 100,000 miles · DE

The contact owns a 2018 Buick Lacrosse. The contact stated that the key fob failed to open the doors and the vehicle was unable to be restarted. The failure had recurred on several occasions. The contact stated that the batteries in the key fob were replaced but the failure persisted. The local dealer was notified of the failure, but no assistance was offered. The manufacturer was not yet contacted. The failure mileage was 100,000.

Filed May 25, 2023 · Electrical, Fuel system · NY

I have brought my 2018 Buick Lacrosse to two different Buick dealerships who say that even though a special instruction letter was recognized and a recall was observed, because my check light went out and the codes on the car where cleared, they will not fix either recall. On three different occasions, the car slowed down to a crawl speed, the check engine light went on and the brakes applied themselves. Also across the dash was displayed 'service transmission'. I thought it was the accelerator pedal position sensor, but it may be a transmission problem. I've had it towed on three different occasions and had the battery replaced. Neither dealership will not fix the problem, however.

Filed Jan 19, 2022 · Acceleration · TX

When I tried to stop at the traffic light, the car suddenly accelerated and went forward. At that time, the car brake was engaged. On the same day; When I tried to go forward at the traffic light, the car suddenly accelerated. The dealer service center said, "We cannot find any issue with the transmission."

Filed Jan 27, 2020 · Electrical · WI

2018 buick lacrosse. Consumer writes in regards to vehicle shutting off suddenly. *ld the consumer stated the battery was replaced, but the failure recurred. The dealer updated the software , but could not guarantee the failure would not recur.

Filed Sep 26, 2019 · Electrical · OH

I received a notice from gm that my vehicle with the electrical connection to the accelerator pedal which could cause a a reduced power and acceleration condition. However, this is not a recall and I should not seek a repair until I have evidence that my vehicle has this problem. This sounds like a serious safety risk to me. If this condition occurs when I am merging into traffic on an interstate, it could cause a serious accident. Apparently owners are supposed to wait for such an occurrence in order to gather evidence of a need for a repair. I want gm to tell me if my vehicle has this defect in advance and, if so, repair it before the disaster occurs.