P3870moderate severityPowertrain
Electronic EGR Cooler Bypass Valve Stuck
on 2009 Audi A3 2.0L TDI · FWD
What this code means
The electronic EGR cooler bypass valve that routes exhaust gas around or through the EGR cooler is stuck.
Symptoms
- Check Engine Light
- EGR gas temperature incorrect
- Higher NOx emissions
- Reduced engine performance
- EGR cooler may overheat or underperform
- Intake manifold carbon buildup changes
Common causes
- Carbon buildup on valve
- Actuator motor failure
- Valve mechanism corroded
- Wiring fault
- Exhaust condensation causing corrosion
Diagnostic steps
- Command EGR cooler bypass valve via scan tool
- Monitor EGR gas temperature upstream and downstream of cooler
- Inspect valve actuator operation
- Test valve position sensor
- Check for carbon deposits on valve
Repair notes
Replace EGR cooler bypass valve. Clean carbon deposits from EGR passages. Inspect EGR cooler for leaks.
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