Mercedes-Benz GLC 300 check engine light comes on

Filed Nov 4, 2026 · Transmission · 75,000 miles · CA

The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that while driving 5 MPH, the vehicle stalled and lost motive power, with the check engine warning light illuminated. The vehicle was able to be restarted. The vehicle was taken to a service center, and the contact was provided DTC: P07B7. The contact was informed that the failure was associated with an internal transmission or software programming failure. The contact was informed that the transmission needed to be replaced and was referred to the dealer for additional assistance. The vehicle was scheduled for an appointment with the dealer. The failure mileage was approximately 75,000.

Filed Aug 31, 2026 · Engine · NH

My check-engine light recently illuminated, and diagnostic testing identified fault code P06DA00, relating to the oil pump control valve circuit. I have been quoted over $5,000 to replace the oil control valve and oil pump harness. I was quoted the following by Mercedes Servuce in Manchester, NH- Oil Pressure Regulator Valve: need to remove lower oil pan only to access oil control valve and replace the valve and sub harness. $5013.52. This is a known issue. My vehicle has been well maintained, and I have been advised that it is otherwise in excellent mechanical condition. I intend to keep and drive this vehicle for many more years, which makes it particularly disappointing to encounter a repair of this magnitude for a component that is not considered a routine maintenance or wear item.

Filed Aug 27, 2026 · Fuel system · CA

After recalls performed trouble code P2402 EVAP leak still is present and check engine light is on

Filed Jun 25, 2026 · Engine, Transmission · CA

My 2020 Mercedes-Benz GLC 300 triggered check engine light with code P06DA (engine oil pressure control) at 40,000 miles. The failed component is an oil pressure control sensor/solenoid worth approximately $200. However, due to Mercedes-Benz's engine design (M264 engine), the entire engine must be removed from the vehicle to access and replace this part. Repair estimate from authorized Mercedes-Benz dealership (Mercedes-Benz of Stevens Creek): $8,391. SAFETY CONCERN: Loss of oil pressure can cause catastrophic engine failure while driving. Engine seizure at highway speeds poses serious risk of loss of vehicle control, potential accident, and harm to occupants and other drivers. This is a known, widespread design defect affecting Mercedes-Benz vehicles equipped with M264/M274 engines across multiple model lines: GLC 300 (2019-2023) C 300 (2019-2023) E 300 (2019-2023) GLC 43 AMG, C 43 AMG GLB 250, A 220, CLA 250 Mercedes-Benz's own authorized dealership confirmed they are "seeing this issue more and more." Despite awareness of this widespread defect, Mercedes-Benz has not issued a recall or Technical Service Bulletin. The design makes repair financially prohibitive ($8,000+), meaning many owners continue driving with compromised oil pressure — creating an ongoing safety hazard on public roads. Mercedes-Benz refused to repair under goodwill, then denied repurchase after 30-day review. They have left consumers with no remedy for a known safety-related design defect. I am requesting the federal safety agency investigate this as a safety defect affecting potentially hundreds of thousands of vehicles.

Filed Jun 3, 2026 · Engine · AL

While driving the vehicle the engine started running rough, check engine light illuminated and it would not accelerate above 40 mph. There are 29,100 miles on the vehicle, it's been serviced on schedule by Mercedes and is owned by me since new. It is especially concerning due to the acceleration topic which could have been catastrophic if I were trying to merge into traffic. Dealer service say the camshaft bearing needs to be replaced. It seems this is very premature for the mileage on the vehicle.

Filed May 20, 2026 · Engine · AL

While driving in my neighborhood at 25 MPH, my Mercedes GLC300 suddenly lost power and the check engine light illuminated. My car would no longer exceed 25-30 MPH, but I drove it straight to the dealership and they said it was a faulty cylinder head and will cost $10,000 to fix! After intense negotiations, they agreed to fix it for $4,205.58, which was better, but still, that’s a lot to pay for a manufacturer’s defect! My car is a 2021 with only 67,540 miles on it.

Filed Mar 25, 2026 · Airbags, Seat belts · NJ

A message that passenger air bag is damaged/will not deploy appears. Passenger seat belt gets stuck and cannot be opened. Check engine light on-pvc valve issue most likely.

Filed Mar 2, 2026 · Fuel system · TX

The contact owns a 2022 Mercedes-Benz GLC300. The contact stated that while driving at various speeds and depressing the accelerator pedal, the check engine warning light was displayed on the instrument panel. The vehicle lost power and was pulled over and restarted. The contact was almost involved in several crashes due to the failure. The vehicle was included in the federal safety agency Campaign Number: 23V445000 (Fuel System, Gasoline); however, the vehicle was repaired, and the failure persisted. The vehicle was taken to the dealer on several occasions, where the fuel pump, charcoal filter, and other various parts of the fuel pump were repaired; however, the failure persisted. The manufacturer was notified of the failure, and the contact was informed that the cylinder head would be replaced free of charge. The contact believed that the vehicle was unsafe to drive due to the failures. The vehicle was not repaired, and a loaner vehicle was provided. The failure mileage was unknown.

Filed Feb 17, 2026 · Electrical, Engine · FL

This is a well-known issue with these engines. See TSB (Service Bulletin) The 2021 Mercedes-Benz GLC 300 has 42,000 miles and the warranty ran out 2 weeks ago. The vehicle is up-to-date on service. Fault code P06DA00 Engine Oil Pressure Control Circuit/Open. The Yellow Check Engine Light came on and the engine does not run properly and causes engine damage. We had to drive it slowly, under 45 mph, to the nearest dealership. This is a safety issue. To replace the oil pump control valve solenoid and the wire harness for this feature is $5009.00 at Mercedes-Benz. The part cost is about $300 retail, and the rest is all labor fees.

Filed Jan 22, 2026 · Engine · SC

Premature oil pump failure on a 2020 Mercedes-Benz GLC 300 with 71,000 miles. The check engine light illuminated on December 29th, 2025 and with no other warning symptoms. The vehicle has been maintained properly, including regular visits to Mercedes-Benz dealerships. The oil pump is a critical engine component that should not fail at this mileage. It has been recommended to not drive the vehicle without repairing as oil can leak onto a hot engine. This issue has been confirmed by a Mercedes dealer. Mercedes-Benz has offered $1,000 in goodwill on a $7,400 repair, which is unreasonably low given the nature of the failure. The dealer is advocating for higher goodwill, but corporate has refused to escalate or provide a breakdown of the offer. This failure appears to be a premature mechanical defect rather than normal wear, and I am filing this complaint to request federal tracking and review.