4B82 - P0401 (DDE)

4B82 - P0401

Information saved in
DDE

Fault code
4B82 - P0401

Fault text
DDE: Exhaust-gas recirculation-rate control, control
deviation: Exhaust-gas recirculation rate too low/positive
control deviation

Fault description
The diagnostic trouble code is logged in the ECU when the
exhaust-gas recirculation system's flow rate control's
positive control deviation exceeds a limit defined based on
the operating point.

Condition for fault identification
Test condition:
The check runs every 20 ms when the specified value
priority assignment is set to flow rate and no other errors
related to the exhaust-gas recirculation have been detected.
Voltage condition:
The check runs every 20 ms when the specified value
priority assignment is set to flow rate and no other errors
related to the exhaust-gas recirculation have been detected.

Condition for fault memory entry
Debounce (4000 ms)

Action in service
Check the following potential problem sources:
1. Mass airflow system on engine-side of compressor is
leaking.
2. Leak in exhaust system upstream from turbine.
3. Defective boost pressure actuator/exhaust turbocharger
(in combination with errors related to the boost pressure
actuator).
4. Defective EGR valve (in combination with EGR valve
errors).
5. Throttle valve defect (in combination with throttle valve
faults).
6. Severe EGR cooler soot accumulation.
Applies to engines with single-stage boost: Conduct mass
airflow system test.

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

Driver information
Warning light:
MIL

Service instruction
Check diagnostic trouble codes for the named components.