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

GF27.60-P-3012ACW Emergency default mode, function
- TRANSMISSION 722.618/640/646/695/699

Function requirements for limp-home mode general
^ Circuit 87 ON
^ Circuit 61 (engine running)

Limp-home mode, general
In order to guarantee a safe driving condition and in order to avoid damage to the transmission, the electronic transmission-control control unit (N15/3) switches to limp-home mode.

Here, a fault code is assigned to the malfunction in the fault memory, and the engine diagnosis indicator lamp (A1e58) in the instrument cluster (A1) goes on.

All solenoid and regulating valves are de-energized.

The modulating pressure and shift pressure increase to the maximum value, the torque converter lockup clutch is shut off. The gear last engaged remains engaged.

After engaging gear range "P" the gear range
"R, D" can then be engaged.

In gear range "D", the transmission shifts to 2nd gear.

As a result the vehicle can be brought to the nearest Mercedes-Benz service operation.

Diagnosis
The faults stored in the fault memory can be read out and erased using the DAS.