P045E

478F - P045E

Information saved in
DDE

Fault code
478F - P045E

Fault text
DDE: Low-pressure exhaust-gas recirculation valve,
plausibility: mechanically faulty near open position

Fault description
If a negative deviation in the low-pressure EGR control
system remains present for a period of 3 s, and it has proven
impossible to resolve this issue despite attempts to free the
valve with the low-pressure EGR actuator in the intervening
period, the system recognizes the low-pressure EGR valve
as sticking in its open position.
For this the actual pulse-duty factor of the low-pressure
EGR actuator must be greater than 7 % and the specified
pulse-duty factor of the low-pressure EGR actuator must be
less than EGRVlvLP_rJamVlvOpnDemMax_C.
A counter is incrementalized in response. This deactivates
monitoring for persistent control deviation.
A diagnostic trouble code is logged when the counter
reaches the limit value 6.

Condition for fault identification
Test condition:
The monitoring function is active only when the monitoring
function for persistent control deviation in the EGR control
system is also active and a persistent control deviation has
already been detected.
Voltage condition:
The monitoring function is active only when the monitoring
function for persistent control deviation in the EGR control
system is also active and a persistent control deviation has
already been detected.

Condition for fault memory entry
-Debounce time for detection of a negative control deviation
5000 ms+ time for break-away attempts during persistent
control deviation 3 s.

Action in service
1. Check low-pressure EGR valve.
2. Replace sensors.
3. Replace low-pressure EGR valve.

Fault effect and breakdown warning
-

Driver information
Warning light:
MIL_SVS

Service instruction
none