4.2.277. SPN 521010, FMI 31, DEF tank heater coolant valve low side power stage over temperatureΒΆ

Description

EEM4 monitoring system has detected over temperature on DEF tank heater coolant valve solenoid low side.

Possible causes are:

  • The valve solenoid wiring is defective
  • The valve solenoid is defective

Reaction in EEM

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

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 valve solenoid wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).
  • Check the operation with another tank heater coolant valve solenoid to see if vale is defective.