GF27.60-P-3012CWQ Emergency Default Mode, Function

GF27.60-P-3012CWQ Emergency default mode, function
- TRANSMISSION 722.9

In order to ensure safe driving and to prevent damage to the automatic transmission, the fully integrated transmission control controller unit (Y3/8) switches to limp-home mode in the event of critical faults. In the event of a hardware fault all the control solenoid valves are switched off. They are then de-energized. In limp-home mode the transmission engages 6th gear. After gear selector switch position "P" is engaged, 2nd gear is engaged in gear selector switch position D. Reverse gear "R" is available with the transmission ratio used for transmission mode S. As a result the vehicle can be brought to the nearest Mercedes-Benz service operation.

If hydraulic faults occur, the transmission does not shift out of the gear currently engaged. If the fault is in the control solenoid valves, the gear affected is locked out and cannot be engaged anymore.
Up to 16 faults can be stored simultaneously in the fault memory. They can be read out using STAR DIAGNOSIS.