P0403 to P0409 and P0486 to P0489: EGR circuit and sensor
The electrical side of the exhaust gas recirculation system has a fault: the valve's control circuit, its position sensor A or B, or the EGR throttle.
SeverityModerateUsually not urgent today, but it can get worse if left.
Can you keep driving?Drive gently, check it soonWhat does P0403 mean?
Where P0401 is about how much gas flows, these codes are about the wiring and the parts that move and measure the EGR valve. The engine computer drives the valve's motor or solenoid and reads its position sensor to confirm it moved. An open or shorted circuit, or a sensor reading out of range, stores one of these codes, usually with the valve left closed as a precaution.
What causes P0403?
- A damaged wire or a corroded connector at the EGR valve, which sits in heat
- A failed motor or solenoid inside the valve
- A faulty position sensor built into the valve
- Carbon jamming the valve so the motor overloads
What to check first for P0403
- Inspect the EGR valve connector for heat damage and corrosion
- Measure the valve motor's resistance and the sensor's reference and signal voltages
- Command the valve open on a scan tool and watch the position follow
- If the valve is carbon-bound, judge whether cleaning or replacing it makes sense
Can you drive with P0403?
Usually safe to drive to a workshop. NOx emissions rise and some engines lose a little power or knock; if the engine idles badly or stalls, keep the trip short.
Since May 2018 an engine warning light that stays on is a major defect at the MOT, so the car fails until the fault is fixed.
Codes on this page
11
- P0403Exhaust Gas Recirculation Control Circuit
- P0404Exhaust Gas Recirculation Control Circuit Range/Performance
- P0405Exhaust Gas Recirculation Sensor "A" Circuit Low
- P0406Exhaust Gas Recirculation Sensor "A" Circuit High
- P0407Exhaust Gas Recirculation Sensor "B" Circuit Low
- P0408Exhaust Gas Recirculation Sensor "B" Circuit High
- P0409Exhaust Gas Recirculation Sensor "A" Circuit
- P0486Exhaust Gas Recirculation Sensor "B" Circuit
- P0487Exhaust Gas Recirculation Throttle Position Control Circuit
- P0488Exhaust Gas Recirculation Throttle Position Control Range/Performance
- P0489Exhaust Gas Recirculation Control Circuit Low
Related codes
Checked on · Rafael Soares
These are the generic meanings every manufacturer shares. Each brand adds its own detail, so your car's handbook, its service information and a qualified mechanic have the last word. OdoKeep has no connection with any manufacturer, and the app does not read codes from the car.
