Mercedes GLC transmission problems

It sounds like you're experiencing some classic symptoms of a transmission oil pressure sensor fault, especially given your description of the warning lights and shifting problems. The error being stored in the memory definitely points to that. Low oil level can absolutely cause these issues, as the sensor relies on adequate pressure to function correctly. Have you checked the transmission oil level? Locating the dipstick can be tricky on some models, and you'll need to use the correct fluid type if you top it off. Also, the grinding noises are concerning and could indicate internal damage if the problem persists. The sensor could be faulty, giving an incorrect reading even if the oil level is fine. What diagnostic codes are being reported by the ECU?

Thank you so much for your prompt response I must admit, I'm not terribly mechanically inclined You mentioned diagnostic codes – how would I go about retrieving those Is it something I can do myself, or would it require special equipment Also, where does one typically find the dipstick for the transmission oil I've only ever checked the engine oil

You're welcome. Retrieving the diagnostic codes usually requires an OBD II scanner. You can buy one online or at most auto parts stores; some even lend them out. Alternatively, a local mechanic can quickly read the codes for you. As for the transmission dipstick location, it varies depending on the GLC's specific transmission. Some models don't have one at all and require checking the level via a fill plug on the transmission pan. Given the potential for further damage and your description of grinding noises, I'd strongly advise against driving it too much and getting it checked by a qualified mechanic as soon as possible. It sounds like a sensor fault, but low oil can seriously damage the transmission if left unchecked.

I appreciate your professional and insightful advice. I took your suggestion and brought my Mercedes to a trusted workshop. It turned out to be precisely as you suspected: a faulty transmission oil pressure sensor. The workshop replaced the sensor, which cost 365€ including labor and parts. The mechanic also changed the transmission oil. The car is now back to its old self, shifting smoothly. Thank you again for pointing me in the right direction!