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

GF27.60-P-3012AHI Emergency default mode, function
- TRANSMISSION 722.930


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

Limp-home mode, general
In order to ensure safe driving and to prevent damage to the transmission, the fully integrated transmission control unit (VGS) (Y3/8n4) switches to limp-home mode in the event of critical faults. A fault code assigned to the malfunction is stored in the fault memory and the engine diagnosis indicator lamp (A1e58) (except code 494 USA version) or the CHECK ENGINE indicator lamp (A1e26) (with code 494 USA version) lights in the instrument cluster (A1).

In the event of a hardware fault, all control solenoid valves are switched off and the transmission switches to 6th gear.

Once gear range "P" has been engaged, gear range "R and D" can also be engaged.

In gear range "D", the transmission shifts to 2nd gear. If hydraulic faults occur, the transmission remains in the gear currently engaged.

In the event of control solenoid valve faults, the affected gear is disabled and no longer actuated. As a result the vehicle can be brought to the nearest Mercedes-Benz service operation.

Diagnosis
Up to 16 faults can be stored simultaneously in the fault memory. These can be read out with DAS.