Maf/gearbox Problem!!!!!!!!

[Voltman]

Hi,
Hope somebody can help, had problem with car over last few weeks. The engine would not tick over when cold & would misfire until it warmed up. Took it to dealers for diagnosis but no faults listed apart from misfires. They quoted a few hundred pounds just to investigate further. After reading & searching many threads on here decided to change the MAF with a new one & problem solved. BUT! i now have a gearbox problem. As soon as i changed the MAF the gear changes are very harsh compared to before & certainly not as smooth. Any ideas as what could have gone wrong or any way to fix. Car is 1999 S320 petrol. Many thanks in advance.

 

[nickmann]

I would try an ECU reset. Easiest way to do this is disconnect the battery for an hour or so. You'll know if it was long enough as the one-touch on the windows will need resetting.

This will clear the autobox ECU, and therefore the adaptive gearchange memory. Go out and drive like a funeral director until the box has been through each change 2 or 3 times. Then drive normally. You will get upshifts at low-ish revs for the next 2-3 times through each change.

If you still have a problem then I'd get the car checked for fault codes.

 

[Voltman]

Thanks for the quick reply, i will try that tonight & post results.

 

[silverarrow]

change atf and filter with power flush

 

[Voltman]

Just to update, had the gearbox oil & filter changed and all is well. The difference the oil change has had is unbelievable, totally smooth from before. Why is this not a service item?

 

[R2D2]

Because, according to Mercedes. "Our gearbox are sealed for life". Changing the gearbox oil should be done every 40/50k I reckon.