GLS Hybrid Automatic Transmission Issue

My 2020 Mercedes GLS hybrid has an automatic transmission fault related to the parking position. The engine won't start, the check engine light is on, and the gearbox shifts erratically. Diagnostic scans show an error pointing to a defective control unit. Has anyone encountered a similar transmission failure concerning the Park brake or Shift lock? Could a faulty Gear linkage be implicated? I anticipate a repair cost of approximately 1000€.

4 comment(s)

I also own a GLS. I had similar symptoms, but perhaps less severe. The engine would start intermittently, and the shifting was rough. My error code also pointed to the transmission. Does your vehicle also struggle when engaging Park?

Engaging Park seems to worsen the issue. The system seems unable to definitively ascertain whether the vehicle is genuinely in Park, which I believe is the root cause of the starting problem. Was your issue also related to a control unit failure, specifically affecting the automatic transmission's ability to detect the parking position?

Yes, the workshop confirmed it was a faulty control unit related to the transmission. They mentioned it affected the Park sensor. Replacement was the only option. I suggest getting yours checked by a qualified mechanic.

I appreciate your input. It seems my suspicions were correct. I shall proceed with taking it to a trusted workshop for diagnosis and repair. Hopefully, replacing the control unit will resolve this transmission failure. Thank you again for confirming my initial assessment.

Join the discussion now: