3.2.238. SPN 4363, FMI 4, SCR catalyst outlet gas temp. sensor voltage below normalΒΆ

Description

The measured SCR inlet gas temp. signal is below the normal operating range (< 0,7 V).

Possible causes are:

  • The outlet gas temp. sensor wiring is defective. (Shorted to ground.)
  • The outlet gas temp. sensor is defective.

Reaction in EEM

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

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

Solution

First save the error log and then clear it. After clearing, restart the ECU. If the fault occurs again during the next driving cycle, check the following paths:

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

See Exhaust gas temperature sensor for reference.