EGR Throttle Control Circuit A Range/Performance
EGR throttle A is electrically OK but does not move as commanded. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
Affected components
- Egr throttle a
Common causes
- High likelihood: Carbon buildup
- Low likelihood: Sensor element aged beyond calibration window
- Low likelihood: Sensor mounting loose - signal damping
Possible symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.