P1084moderate severityPowertrain
Fuel Control Mixture Rich Bank 1
on 2000 BMW M5 4.9L V8 S62 · RWD
What this code means
The DME detected a rich fuel mixture condition on Bank 1 that exceeds the long-term fuel trim correction range. The engine is receiving too much fuel or insufficient air, and the adaptive system can no longer compensate.
Symptoms
- Check Engine Light
- Black exhaust smoke
- Fuel smell from exhaust
- Rough idle
- Poor fuel economy
Common causes
- Leaking fuel injectors Bank 1
- Faulty O2 sensor Bank 1 reporting false lean
- High fuel pressure
- EVAP purge valve stuck open
- Crankcase ventilation valve (CCV) failure
Diagnostic steps
- Monitor fuel trim values on Bank 1
- Test O2 sensor response Bank 1
- Check fuel pressure regulator
- Inspect EVAP purge valve operation
- Test CCV valve for proper sealing
Repair notes
Replace faulty O2 sensor or repair fuel delivery issue causing rich condition.
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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
29E1
Lambda Additive/Idle Adaptation Limit, Bank 2
29E2
Lambda Multiplicative Part-Load Adaptation Limit, Bank 1