SCR system
Proceed as follows: Carry out the test "Checking the reductant circuit" using SDP3 under EEC3>Inspection>Guided troubleshooting. The test is stopped if the overflow valve opens when the pressure is too low. Check the connectors and electrical cables between the EEC control unit and the reductant pressure sensor in the reductant doser. If the connectors and electrical cables seem to be intact, renew the overflow valve in the reductant pump. If there are other active fault codes which indicate that the reductant pressure sensor is defective, renew the reductant doser. When the fault has been rectified the fault code can be deactivated by carrying out "Checking the reductant circuit" using SDP3.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
The reductant pressure is lower than permitted when the overflow valve is open.
Possible causes: The overflow valve in the reductant pump opens when the pressure is too low. Reductant pressure sensor in reductant doser indicates values that are too low.