P0403: EGR A Control Circuit/Open
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes - driveability is usually normal until the fault affects flow.
Symptoms
- Check engine light
- Occasional rough idle
- Emissions test failure
Likely causes, most common first
- Open circuit in the EGR control wiring
- Failed EGR solenoid or valve motor
- Connector corrosion
- Blown fuse on the control circuit
Read P0403 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P0403 is an electrical fault in the circuit that commands the EGR valve, rather than a complaint about flow. The computer watches the current through its own output driver, and an open or shorted circuit sets this code even if the valve is mechanically perfect.
Because it is an electrical code, the diagnosis is electrical: check for power and ground at the connector, then measure the solenoid or motor winding against specification. That sequence separates a broken wire from a failed valve without removing anything.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning P0403
“Was driving on highway when given error ""Propulsion Power Reduced." This resulted in less power available, which is a safety hazard. Then after a while of driving (on the highway) I received the error "Engine Not Available," which caused me to have to continue on electric only power. If I did not have any battery left in the traction battery, I would have had to maneuver to the shoulder. The error code revealed by a scan with the OBD device P0403 relates to a failed EGR valve. There are no replacement parts for this valve, according to GM, so future failure is likely.”2017 Chevrolet Volt · Jun 2024
“At 5,800 miles my engine light came on. I took it to Auto Zone to have them plug the reader in and the error was "P0403" related to the EGR valve malfunction. Of course like I mentioned in another report I filed today... after a few days of driving the car it magically turned off on its own so I did not take it to the dealership because the appointment was for days after the check engine light went off on its own.”2022 Mitsubishi Outlander · Jun 2022
“Lack of power or runs rough condition, and/or the malfunction indicator light on with egr related diagnostic trouble codes (p0401, p0402, p0403, p0404, p0405, or p0406). Engine and engine cooling:exhaust system:emission control:gas recirculation valve (egr valve). *tr”NHTSA complaint · Mar 2014 · 40,000 mi
Cars that report P0403 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P0403?
Yes - driveability is usually normal until the fault affects flow.
How much does it cost to fix P0403?
Typical US repair costs range from $20 for the simplest fix (wiring repair) to $700 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P0403. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.