46B9 - P2201 (DDE)

46B9 - P2201

Information saved in
DDE

Fault code
46B9 - P2201

Fault text
DDE: NOx sensor before DeNOx cat., plausibility NOx:
NOx signal offset too low

Fault description
Monitoring of NOx signal offset value (NOx sensor 1 before
SCR). The diagnostic trouble code is logged when the
average offset falls below the limit of -30 ppm. The offset is
calculated by averaging the pressure-compensated signal
ppm with the constant 1.

Condition for fault identification
Test condition:
The test routine is executed when the signal flank rises for a
duration of 6 s. Within this time frame the absolute
difference between the maximum and minimum NOx value
must be less than 2 ppm. Once the diagnostic function is
enabled the test routine is executed continuously in
accordance with the defined process grid.
Voltage condition:
The test routine is executed when the signal flank rises for a
duration of 6 s. Within this time frame the absolute
difference between the maximum and minimum NOx value
must be less than 2 ppm. Once the diagnostic function is
enabled the test routine is executed continuously in
accordance with the defined process grid.

Condition for fault memory entry
Event debounced (1)

Action in service
Use SCR converter system check to analyse NOx sensor 1
(before SCR).
ID0004
ID0005
3. Replace NOx sensor 1 (before SCR).

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

Driver information
Warning light:
MIL

Service instruction
-