4D02

4D02 - P20E8

Information saved in
DDE

Fault code
4D02 - P20E8

Fault text
Reducing agent, pressure control, vacuum fault: Pressure of
reducing agent too low

Fault description
Monitoring reduction agent metering. The diagnostic trouble
code is logged when the specified pressure for the metering
module falls below the minimum pressure threshold
3100 mbar for at least 30 s
or if the pressure, for a period of at least 15 s, is below the
second minimum pressure threshold 2900 mbar.

Condition for fault identification
none

Condition for fault memory entry
Debounce (0 ms)

Action in service
Depends on cause:
1. Refill reduction medium.
2. Replace any 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 pick-up point?
Is the delivery module drawing air between the pick-up
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 open?