Overspeed Detection

P138800

Diagnostic information - DME control unit

Overspeed detection

DANGER
High voltage.
Death or severe injuries due to high voltage or high current.

- De-energise the vehicle in accordance with the guidelines.
- Work must not be performed on parts carrying a high voltage.

The control unit must be active in order to test internal function sequences and diagnosable inputs/outputs.
In the event of a fault, check whether the fault is permanently >present<. To perform the check, erase the fault memory, meet the diagnostic conditions and read out the fault memory again.

NOTE:
- Torque reduction or shut-off
- Fault also occurs in the event of shift error

If the engine limit speed is exceeded, the throttle valve is closed and is then opened again only when the speed has fallen below this limit.

Diagnostic conditions
- Ignition on

Possible fault causes
- Maximum engine speed exceeded.