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GM6 Automatic Gearbox



GM6 Automatic Gearbox

GM6 automatic gearbox
The GM6 automatic gearbox is a fully automatic 6-speed automatic gearbox for back-wheel / all-wheel drive with electronic control.

Brief description of components
The GM6 automatic gearbox consists essentially of the following components:
- Torque converter
- Converter housing
- Integrated oil pump
- 2 planetary gear sets
- 5 multi-plate clutches
- Mechatronics module
The mechatronics module is a combination of a hydraulic control unit (hydraulic selector unit) and an electronic module.
The hydraulic control unit is the hydraulic part of the gearbox control.
The electronic module contains the EGS control unit, the sensors as well as the electrical connections inside the gearbox.

System functions
The following system functions are described:

Emergency program
The emergency program is activated on failure of the gearbox control or on detection of faults that lead to critical driving states. In the emergency program, the vehicle can still be driven with certain restrictions.

There are two different types of emergency program:
Hydraulic emergency program
In the event of failure of an electrical component, the gearbox can switch into the hydraulic emergency program. In this case, all the solenoid valves are switched off and the gearbox shifts, if the 1st, 2nd or 3rd gear is engaged, permanently into 3rd gear.
If the 4th, 5th or 6th gear is engaged in the event of failure of the electrical equipment, the gearbox shifts permanently into 5th gear.
When the gearbox is operating in the emergency program, 5th gear is engaged and the ignition is switched of and on again, the gearbox shifts to 3rd gear.

Electrical emergency program
If a gripping clutch does not correctly engage or the releasing clutch does not correctly disengage, the gearbox control can switch into the emergency program. The gearbox works in the restricted mode. Defective clutches are not used. This means that only a limited number of gears is available.

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