Commonly 0b5 transmission problems occur when the mechatronics fitted to the DL501 Direct Shift Gearbox (DSG) becomes faulty. The Audi gearbox malfunction warning and EPC warning light will often show and symptoms such as no gear selection, loss of certain gears, harsh/jerky changes and limp mode will begin to occur.
We see a vast amount of Audi S Tronic DSG mechatronic units in for repair with various fault codes ranging from P17D8 – Torque Limitation Due To Clutch Temperature, P17D6 – Clutch 1 Pressure Too High and P17D7 – Clutch 2 Pressure Too High to P0726 – RPM Signal Of Engine Control Unit (Implausible Signal), P173C – Valve 1 In Sub-gearbox 1 (Electrical Fault) and P173F – Valve 2 In Sub-gearbox 1 (Electrical Fault)
Common Failure Symptoms:
No reverse gear
No gears above 1st/ Not changing gear
Gears sticking
No gears at all
Limp home mode
Harsh gear change
Jerking / behaving erratically
https://www.ecutesting.com/common-faults/audi/audi-s-tronic-0b5-gearbox-mechatronic-problem/