P1085moderate severityPowertrain
Fuel Control Mixture Lean Bank 2
on 2004 BMW 325i 2.5L I6 M54 · RWD
What this code means
The DME detected a lean fuel mixture condition on Bank 2 beyond the correction capability of the long-term fuel trim. This often accompanies P1083 on V-configuration engines but can appear independently on Bank 2.
Symptoms
- Check Engine Light
- Rough idle
- Lean misfire under load
- Hesitation
- Poor fuel economy
Common causes
- Vacuum leak on Bank 2 intake side
- Weak or clogged fuel injectors Bank 2
- Low fuel pressure
- Faulty MAF sensor
- Intake manifold gasket leak Bank 2
Diagnostic steps
- Smoke test for vacuum leaks focusing on Bank 2
- Compare fuel trims Bank 1 vs Bank 2
- Test fuel pressure and volume
- Inspect intake manifold gasket
- Test individual injector flow rates
Repair notes
Repair vacuum leaks or fuel delivery issues on Bank 2 side.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1