2.2.252. SPN 4754, FMI 4, DOC outlet temperature sensor: Electrical signal below normal, possible reason is open circuit.ΒΆ

Description

The measured DOC outlet gas temperature signal is below the normal operating range.

Possible causes are:

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

Reaction in EEM

The FC is stored and the warning lamp is activated. The CAN message indicates an active fault.

NOTE: The present fault is classified as an emission related fault. Engine power is reduced after a certain time which is defined by an authority.

Solution

First save the error log and then do the procedure that follows:

  • Measure the sensor resistance value at a known temperature.
  • Check the DOC outlet gas temperature sensor wiring, the connectors and the contact surfaces of the connector pins. (possible oxidation)
  • Check the operation with another DOC outlet gas temperature sensor to see if the sensor is defective.

See Exhaust gas temperature sensor for reference.