P0404moderate severityPowertrain
EGR Control Circuit Range/Performance
on 2021 Mazda Mazda3 2.5L I4 · FWD
What this code means
The EGR valve is not responding as commanded by the PCM.
Symptoms
- Check Engine Light
- Rough idle
- Stalling
- Poor performance
Common causes
- Carbon restricting EGR valve movement
- Faulty position sensor in EGR
- EGR valve mechanically stuck
Diagnostic steps
- Command EGR open/closed with scan tool and monitor position
- Check for carbon restricting movement
- Test position sensor
Repair notes
Clean or replace EGR valve.
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