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

GF27.60-P-3012AHK Emergency Default Mode, Function
- TRANSMISSION 722.904 /906 /907 /999 in MODEL 171.4 as of Model Year 09 /modification year 08 model refinement package

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.

In the process a fault code assigned to a fault is stored in the fault memory and the engine diagnosis indicator lamp (A1e58) (except code 494 USA version) or the CHECK ENGINE engine indicator lamp (A1e26) (with code 494 USA version) lights up 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.

After gear range "P" is engaged, gear range "R and D" can 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.