P0400
Exhaust Gas Recirculation (EGR) Flow
1992-1998 BMW 325i E36 2.5L I6 M50 🇬🇧
Moderate SeverityPowertrain
Description
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.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P0400 on Other Vehicles
Common Questions
What does code P0400 mean on a 1992-1998 BMW 325i E36?
P0400 stands for "Exhaust Gas Recirculation (EGR) Flow". The EGR system flow is not within expected parameters.
What are the symptoms of P0400 on a BMW 325i E36?
Common symptoms of P0400 include: Check Engine Light, Rough idle, Pinging/knocking, Increased NOx emissions, Failed emissions test.
What causes P0400 on a 1992-1998 BMW 325i E36?
Common causes of P0400 include: Clogged EGR passages, Faulty EGR valve, EGR valve stuck closed, Carbon buildup, Vacuum line issue.