2.2.80. SPN 175, FMI 3, Oil temperature sensor: Electrical signal above normal, possible reason is open circuitΒΆ

Description

The measured oil temperature signal is above the normal operating range (> 4,9 V). Note: Same sensor measures oil pressure and oil temperature.

Possible causes are:

  • The oil temperature sensor wiring is defective. (Shorted to high source or open circuit.)
  • The oil temperature sensor power supply is not correct.
  • The oil temperature sensor is defective.

Reaction in EEM

The FC is stored and the fault lamp is activated. Engine power is reduced (Degradation Level 1). The CAN message indicates an active fault. The engine protection functions that depend on oil pressure are not active.

Solution

First save the error log and then erase it. Restart the ECU after erasing the error log. If the fault occurs again during the next driving cycle, check the following paths:

  • Check the oil temperature sensor wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).
  • Check the 5 V power supply to the sensor.
  • Check the operation with another oil temperature sensor to see if the oil temperature sensor is defective.

See Oil pressure sensor for reference.