Emergency default mode, function - GF27.60-P-3012SX
TRANSMISSION 722.9 in MODEL 216, 221, 251.0 /1 up to Model Year 8
In order to ensure a safe driving state and to prevent damage to the automatic transmission, the electric controller unit (VGS) (Y3/8) switches to the limp-home mode if critical faults occur. 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.
In the fault memory up to 16 errors can be stored simultaneously. They can only be read out using STAR DIAGNOSIS.
| VGS control unit, component description | Model 216, 221 | GF27.19-P-4016SX | |
| Model 251.0/1 | GF27.19-P-4016RT | ||
| Control solenoid valve component description | Working pressure control solenoid valve | GF27.19-P-5147GA | |
| Clutch control solenoid valve K1 | GF27.19-P-5147GB | ||
| Clutch control solenoid valve K2 | GF27.19-P-5147GC | ||
| Clutch control solenoid valve K3 | GF27.19-P-5147GD | ||
| Brake control solenoid valve B1 | GF27.19-P-5147GE | ||
| Brake control solenoid valve B2 | GF27.19-P-5147GF | ||
| Brake control solenoid valve B3 | GF27.19-P-5147GG | ||
| Torque converter lockup clutch control solenoid valve | GF27.19-P-5147GH |