Manufacturer Code Charts: 4809

4809 - P20A5

Information saved in
DDE

Fault code
4809 - P20A5

Fault text
DDE: SCR pressure regulation, pressure loss fault:
Reducing-agent pressure drop too slow during back suction

Fault description
SCR monitoring: Urea metering depressurization. If it is not
possible to reduce the pressure in the urea metering system,
within the period 3000 ms, below the limit value 500 mbar,
then the diagnostic trouble code is logged.

Condition for fault identification
Test condition:
The error check only runs when the SCR monitoring
system's status coordinator is at depressurization status.
Voltage condition:
The error check only runs when the SCR monitoring
system's status coordinator is at depressurization status.

Condition for fault memory entry
Event debounced (3)

Action in service
Replace delivery module.

Fault effect and breakdown warning
-

Driver information
Warning light:
MIL

Service instruction
If the error occurs in combination with 4D02 and 4804 then
the pump in the delivery module is defective (the pump is
also employed for rapid depressurization).