P0400moderate severityPowertrain
Exhaust Gas Recirculation (EGR) Flow
on 1997 BMW 328is E36 2.8L I6 M52 · RWD
What this code means
The EGR system flow is not within expected parameters.
Symptoms
- Check Engine Light
- Rough idle
- Pinging/knocking
- Increased NOx emissions
- Failed emissions test
Common causes
- Clogged EGR passages
- Faulty EGR valve
- EGR valve stuck closed
- Carbon buildup
- Vacuum line issue
Diagnostic steps
- Test EGR valve operation
- Check EGR passages for carbon buildup
- Test vacuum supply to EGR valve
- Monitor EGR position with scan tool
- Inspect EGR tube
Repair notes
Clean EGR valve and passages. Replace EGR valve if stuck or faulty.
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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