P0403 — Exhaust Gas Recirculation Circuit Malfunction
Category: Powertrain Severity: Medium
Updated:
DTC code P0403 means: Exhaust Gas Recirculation Circuit Malfunction. It falls under the "Powertrain" category, with an estimated severity of Medium. Common causes include faulty EGR valve stuck open or malfunctioning, faulty EGR position sensor and wiring/connector issue; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Faulty EGR valve stuck open or malfunctioning
- Faulty EGR position sensor
- Wiring/connector issue
- Carbon buildup affecting valve movement
Symptoms
- Rough or unstable idle
- Engine hesitation or stalling
- Check engine light on
- Possible failed emissions test
How to diagnose it step by step
- Check the EGR connector and wiring.
- Measure EGR solenoid or motor resistance.
- Check supply.
- Replace the EGR valve.
How to fix it
Check the EGR valve for carbon buildup that could keep it stuck; clean or replace it if needed. Test the position sensor and its wiring separately before assuming the valve itself is bad.
Estimated repair cost
$200–650.
Frequently asked questions
What does DTC code P0403 mean?
Exhaust Gas Recirculation Circuit Malfunction.
Is code P0403 serious?
Severity Medium. Not urgent, but worth diagnosing to avoid bigger damage.
Can I keep driving with code P0403?
Yes, carefully.
Related codes
P0402 P0404 P0401 P0405 P0400 P0406 P0410 P0411 P0420 P0421
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