2.2.248. SPN 4753, FMI 9, DOC inlet temperature sensor: Temperature value frozen.

Description

The DOC inlet temperature value didn’t changed during engine warm up.

Possible causes are:

  • The DOC inlet temperature sensor is removed from the exhaust line.
  • The DOC inlet temperature sensor is disconnected.
  • The DOC inlet temperature sensor is cross-connected with the DOC outlet, SCR inlet or the SCR outlet sensor.
  • The DOC inlet temperature sensor wiring is defective.
  • The DOC inlet temperature 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:

  • Make sure that the DOC inlet temperature sensor installation is correct.
  • Examine that the exhaust temperature sensors are not cross-connected.
  • Examine the DOC inlet temperature sensor wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).
  • Try the operation with another DOC inlet temperature sensor to see if the sensor is defective.