BMW Goes Into Failsafe
This bulletin applies to 2010 BMW 335i xDrive vehicles. The transmission may go into failsafe mode, with fault code 4F8D (ratio monitoring, gearshift 5-4 – plausibility) stored in the EGS. The cause is over-sensitive EGS software.
The fault may occur during a 5-4 downshift only in vehicles with either low mileage, a replacement transmission or after a reset of the adaptation values.
The transmission adaptation occurs only at a transmission oil temperature of 75 degrees Celsius or higher (167 Fahrenheit). Once the transmission oil temperature of 167 F has been reached, carry out the adaptation as follows:
1. In drive position D, increase vehicle speed up to 4th gear at about 25 mph, but do not allow a shift into 5th gear.
2. Allow the vehicle to then coast to a stop and keep the vehicle stationary for about 15 seconds with the brake pedal applied.
3. Next, with the vehicle stationary, change from D to N and back again to D.
4. Repeat steps 1 to 3 approximately 10 times.