1999 E320 W210
The code you posted refers to the transmission controller. It could be that the transmission is not shifting fully to top gear which would explain low gas mileage. But if the car drives okay start by carefully measuring the gas mileage. For best results fill up at the same pump before and after and use the trip odometer to measure distance. You should get between 15-19 mpg city driving and 25-29 mpg highway while driving conservatively.
Interpreting MB specific trouble codes is best left to a dealer or MB tech with MB diagnostic instruments. It's worth the trouble since if the transmission fails, a rebuilt trannie and installation can be close to $5K!






