Fan rotational speed
Check that the fan is rotating as it should.Check that there is supply voltage (12 V) to the sensor.Check the coolant temperature sensor, charge air pressure sensor, charge air temperature sensor, fuel supply pressure sensor and fan speed sensor, along with the connectors and electrical cables in the circuit.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
The signal from the rotation speed sensor for the fan has been lower than normal.
Possible causes:Fault in the rotation speed sensor for the fan or in its connections.The poly-V-belt is broken. Mechanical fault in the fan so that it does not rotate properly.Fault in the circuit for the charge air pressure sensor, charge air temperature sensor, fuel supply pressure sensor or fan speed sensor.