29E1moderate severityPowertrain
Lambda Additive/Idle Adaptation Limit, Bank 2
on 2020 BMW 530i 2.0L I4 Turbo B48 · RWD
What this code means
The long-term fuel trim at idle/additive range has reached its correction limit on bank 2, indicating a lean or rich mixture (OBD P0173). The ECU cannot correct the air/fuel imbalance further.
Symptoms
- Rough idle
- Check engine light
- Poor fuel economy
Common causes
- Vacuum/intake air leak
- Faulty MAF sensor
- Leaking or dirty fuel injectors
- Faulty oxygen sensor
Diagnostic steps
- Read fuel trim values with scan tool
- Smoke test intake for leaks
- Inspect MAF sensor readings
- Check fuel pressure and injectors
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Other Powertrain codes on this vehicle
29CC
Misfire Cylinder 1
29CD
Misfire Cylinder 2
29CE
Misfire Cylinder 3
29CF
Misfire Cylinder 4
29D0
Misfire Cylinder 5
29D1
Misfire Cylinder 6
29D2
Misfire Cylinder 7
29E0
Lambda Additive/Idle Adaptation Limit, Bank 1
29E2
Lambda Multiplicative Part-Load Adaptation Limit, Bank 1
29E3
Lambda Multiplicative Part-Load Adaptation Limit, Bank 2