3.2.183. SPN 3521, FMI 17, DEF quality sensor: Concentration LOW warning

Description

The AdBlue suction module is installed in the SCR tank. The suction module is an independent unit which measures all the critical parameters of the aqueous urea solution.

The measured DEF quality indicates: The urea concentration is too low.

Reaction in EEM

The FC is stored and the warning lamp is activated.

Solution

• Check the used reducing agent (DEF/AdBlue) quality. If there are any suspicions that a poor quality reducing agent has been used, the tank needs to be emptied and flushed.
• Refill the DEF tank with valid reducing agent (AdBlue).

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 operation with another AdBlue suction module.