Emergency default mode, function - GF27.60-P-3012GGA

TRANSMISSION 722.902 in MODEL 463.306/336/346 up to 31.5.12 as of Model Year 2011/YoM 10 

TRANSMISSION 722.904 in MODEL 463.202/222/236/237 up to 31.5.12 as of Model Year 2009/YoM 08 

TRANSMISSION 722.902 in MODEL 463.303/340/341 up to 31.5.12 as of Model Year 2009/YoM 08 

Function requirements for limp-home mode, general 

• Circuit 87 ON
• Circuit 61 ON

Limp-home mode, general 

To ensure a safe driving condition and to avoid any damage to the transmission, the fully integrated transmission control unit (VGS) (Y3/8n4) shifts in the event of critical faults into the limp-home mode. The fault is stored with the relevant fault code in the fault memory, and the CHECK ENGINE indicator lamp (A1e26) (with code (ZU8) USA version) or the engine diagnosis indicator lamp (A1e58) (except code (ZU8) USA version) is actuated in the instrument cluster (A1). The fault is also sent to the ME-SFI [ME] control unit (N3/10) (with gasoline engine) or to the CDI control unit (N3/9) (with diesel engine).

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

After engaging gear range "P" it is possible to engage gear range "R" or "D".

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 using the ISE Tester.