4C9E

4C9E - P042F

Information saved in
DDE

Fault code
4C9E - P042F

Fault text
DDE: Exhaust-gas recirculation valve, plausibility:
mechanically faulty near closed position

Fault description
If a positive or negative deviation in the EGR control system
remains present for a period of 1 s, and it has proven
impossible to resolve this issue despite attempts to free the
valve with the EGR actuator in the intervening period, the
system recognizes the EGR valve as sticking in its closed
position.
For this the actual pulse-duty factor of the EGR actuator
must be less than 1 % or the specified pulse-duty factor of
the EGR actuator greater than
EGRVlv_rJamVlvOpnDemMax_C.
In this case a counter starts advancing. This deactivates
monitoring for persistent EGR 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 permanent control deviation in the EGR control
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 permanent control deviation in the EGR control
is also active and a persistent control deviation has already
been detected.

Condition for fault memory entry
-Debounce time for detection of positive control deviation
2500 ms+ time for break-away attempts with persistent
control deviation 1 s or
time to recognition of negative control deviation error
2500 ms+ time during which enable function is active 1 s.

Action in service
With electric EGR valve:
Replace EGR valve.
With pneumatic EGR valve:
Check the vacuum system between the following
components and repair as required:
- Pressure converter for EGR valve.
- EGR valve.
If the vacuum system is OK:
Replace EGR valve.

Fault effect and breakdown warning
Proceed to the nearest BMW Service facility.

Driver information
Warning light:
MIL

Service instruction
With some engine versions the appropriate service function
must be used to reset the EGR valve's adaptation before the
EGR valve is replaced.