421B — Exhaust gas recirc. control during particulate filter regeneration deviation
Severity: Warning
Can you drive? With caution: limp mode possible, have it checked soon
Make: BMW
| Meaning | Exhaust gas recirc. control during particulate filter regeneration deviation. |
| Family | Manufacturer-native code |
Frequently asked questions
What does code 421B mean?
Exhaust gas recirc. control during particulate filter regeneration deviation. Exhaust gas recirc. control during particulate filter regeneration deviation.
Can I keep driving with code 421B active?
With caution: limp mode possible, have it checked soon
How do you fix code 421B?
Diagnosis starts from reading the live ECU parameters: the code points to the fault area, not to the part to replace. A vehicle-electronics specialist can test the component and clear the code after the repair.
Need help with this fault?
We are ECU specialists: diagnosis, file repair and remapping for cars, bikes, trucks and agricultural vehicles.
Contact us
Where to get it fixed
Related codes
- 42 — ADS
- 42 — DDE Error EEPROM or Coding
- 42 — Speed Signal or Knock Sensor 2 (DME 1.7.x or 3.3.1)
- 42 — Multi Function Steering Wheel Plausibility
- 4203 — Glow Module Communication
- 4203 — Glow Module Communication
- 4205 — Lambda Sensor Heating -Short Circuit to B+
- 4205 — Lambda Sensor Heating Short Circuit to B+
- 4206 — Lambda Sensor Heating -Short Circuit to B
- 4206 — Lambda Sensor Heating Short Circuit to B
- 4207 — Lambda Sensor Heating
- 4207 — Lambda Sensor Heating