Oil temperature gauge

On the M-models, an oil temperature gauge is used in the instrument cluster instead of the fuel consumption indicator.

The oil temperature displayed in the instrument cluster comes via the CAN bus from the digital engine electronics to the instrument cluster. On the S62 engine, the oil temperature shown in the instrument cluster is displayed as a mean value of the oil temperature measured value of the oil level transmitter and the dual coolant temperature sensor (temperature engine exit).

Procedure in the event of a fault:

1. Check the instrument cluster

Run a self-test of the instrument cluster.

For the self-test of the instrument cluster, check whether the oil temperature gauge behaves correctly. If it does not, the instrument cluster must be replaced.

2. Check the thermal oil level transmitter

If the oil temperature gauge is defective with the additional Check Control message ”Check engine oil level”, proceed as follows:

• Check the power supply and earth connection for the oil level transmitter.
  
• Check the cable from the oil level transmitter to the DME control unit.
  
• If necessary, replace the oil level transmitter.
  

If the oil temperature gauge is defective without the additional Check Control message ”Check engine oil level”, proceed as follows:

• In the diagnostic program for the DME digital engine electronics, display the oil temperature (expert mode - diagnosis requests) and check whether the displayed temperature corresponds to the oil temperature in the engine.
  
• Check the cable from the oil level transmitter to the DME control unit.
  

• If necessary, replace the oil level transmitter.
  

3. Check the dual coolant temperature sensor

The dual coolant temperature sensor has two independent NTC sensors that determine the coolant temperature directly for the instrument cluster and for the digital engine electronics. The NTC sensor connected to the digital engine electronics is used to calculate the oil temperature.

• In the diagnostic program for the DME digital engine electronics, display the coolant temperature (expert mode - diagnosis requests) and check whether the displayed temperature corresponds to the coolant temperature in the engine.
  
• Check the cable from the DME control unit to the sensor.
  
• If necessary, replace the sensor.