4804 - P20E8 (DDE)

4804 - P20E8

Information saved in
DDE

Fault code
4804 - P20E8

Fault text
DDE: Reducing-agent pressure buildup, plausibility: no
reducing-agent pressure increase possible

Fault description
SCR monitoring: Reduction agent pressurization. A timer is
incrementalized if the urea metering system fails to reach
the limit value 3500 mbar within the period 11000 ms.
When the number of failed pressurization attempts exceeds
the limit value 3 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 pressurization status.
Voltage condition:
The error check only runs when the SCR monitoring
system's status coordinator is at pressurization status.

Condition for fault memory entry
Event debounced (1)

Action in service
Depends on cause:
1. Refill reduction medium.
2. Replace leaking components.
3. Replace delivery module.

Fault effect and breakdown warning
-

Driver information
Warning light:
MIL

Service instruction
Is reduction agent in the tank (check tank levels)?
In winter: Is the tank completely frozen, meaning that no
reduction agent is at the suction point?
Is the delivery module drawing air between the suction point
in the tank and the delivery module? Is a major leak present
in the metering system (perform SCR system test and visual
inspection for leaks)? Is the metering module sticking?