Our Td6 had a reconditioned gearbox about 4 years/20,000 miles ago.

Today I was towing a trailer with it and the 'trans fail safe message' came up on the screen and it seemed to start hanging on to the lower gears and not changing up.

I have checked the codes with an i-carsoft scanner and it is giving the fault '5th gear incorrect ratio'. I tried clearing the codes but the fault came back straight away again.

Has anyone got any idea what it might be? I am hooping that it might be gearbox ECU, or solenoid related and a relatively cheap fix but I suspect that I won't be that lucky!

Glen.