P0400moderate severityPowertrain
Exhaust Gas Recirculation (EGR) Flow
on 1998 BMW 328is E36 2.8L I6 M52 ยท 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