| Safety functions of automatic gearbox control unit -J217- |
| If faults occur while driving, the automatic gearbox control unit -J217- can activate back-up functions or "emergency running programs". These backup functions may affect the function and smoothness of the gear changes. |
| Depending on the „severity“ of the fault, the control unit can react by: |
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| Controlling gear changes according to engine speed only, |
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| Controlling gear changes with increased pressure, which will be felt by the driver as „hard“ gearshifts with a noticeable jolt, |
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| Or by engaging 4th gear with torque converter slip (4H). |
| The gearbox will continue to run in the back-up mode until the fault is rectified or no longer detected by the control unit over a predetermined period. |
| Faults in event memory which can activate back-up mode |
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| Open circuit in wiring, short circuit, electrical or hydraulic components defective |
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| Open circuit and/or fault in CAN bus wiring |
| If the engine or gearbox control unit is renewed, the system must be reset to the basic setting → Chapter. |
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