P0403 on Ford: How to Diagnose & Fix
Exhaust Gas Recirculation Circuit Malfunction
2 Ford models · 2 documented issues · 2 critical · $800-$3,500 repair
P0403 on Ford by model: symptoms, diagnosis and fix
The EGR (Exhaust Gas Recirculation) cooler on 2011-2019 6.7L Power Stroke diesel engines is prone to clogging with soot and eventually failing, particularly on trucks used for highway driving, light loads, or trucks that idle extensively. The EGR cooler recirculates cooled exhaust gas back into the intake to reduce NOx emissions. Over time, soot accumulates in the cooler's internal passages until coolant flow is restricted, causing the cooler to overheat and fail. When it fails, exhaust gases enter the coolant system, causing overheating and "puking" coolant from the degas bottle. The 2011-2014 models are particularly susceptible due to narrow internal coolant passages. Ford issued TSBs for 2011-2014 trucks covering EGR cooler cleaning/replacement under extended warranty up to 120,000 miles. The EGR cooler for 2011-2016 is OEM part BC3Z-9V425-A; 2017+ is HC3Z-9V425.
Common Symptoms
- Coolant loss with no visible external leak
- Coolant reservoir overflows or "pukes" coolant
- White smoke from exhaust (coolant in combustion)
- Engine overheating warning
- DTC codes P0401 (Insufficient EGR Flow) or P2457 (EGR Cooler Performance)
- Bubbling or foaming in coolant degas bottle
- Loss of power under load (especially towing)
- White deposits around degas bottle cap
How to Fix
Replace EGR cooler (BC3Z-9V425-A for 2011-2016; HC3Z-9V425 for 2017+). Check if truck qualifies for Ford extended service coverage with active DTC P0401 (Insufficient EGR Flow) or P2457 (EGR Cooler Performance). Some 2011-2014 trucks covered to 120,000 miles. Preventive: use a fuel additive (Diesel Kleen, Hot Shots Secret EDT) to reduce soot. Perform regular EGR cleaning at 60,000-mile intervals. Upgrade kits from Sinister Diesel and Dorman (904-405 kit) include both EGR cooler and gaskets.
Sources for this issue (1)
Ford's 26S10 safety recall includes certain 2025 Broncos. The problem is the exhaust gas recirculation (EGR) valve, which may fail and cause the Bronco to lose drive power unexpectedly. NHTSA's stated consequence is an increased risk of a crash — worth taking seriously given where these trucks get driven and the fact that the loss of power comes without warning. The recall covers 47,804 vehicles campaign-wide across multiple 2025 Ford and Lincoln models, so that number should not be read as a Bronco-only total.
Common Symptoms
- Unexpected loss of drive power while driving
How to Fix
The fix is a free EGR valve replacement performed by a Ford dealer under recall 26S10. Owner notification letters were mailed July 31, 2026, and affected VINs have been listed on NHTSA.gov since March 4, 2026 — run your VIN at nhtsa.gov/recalls to confirm your Bronco is included and book the free repair. Ford customer service: 1-866-436-7332.
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Sources for this issue (1)
P0403 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0403 mean on a Ford?
P0403 stands for "Exhaust Gas Recirculation Circuit Malfunction." This emissions code indicates a malfunction in the exhaust gas recirculation (EGR) control circuit. The EGR system routes a small amount of exhaust back into the intake to lower combustion temperatures and reduce nitrogen-oxide emissions, and the computer commands the EGR valve open and closed through this circuit. The code sets when the electrical control signal to the EGR valve or its solenoid is out of the expected range — for example, an open, short, or a commanded change that doesn't produce the right feedback. It generally points to an electrical or wiring problem in the EGR control circuit, or the EGR valve/solenoid itself, rather than carbon clogging alone. On Ford it is documented across 2 models: F-250 Super Duty, Bronco.
What are the most common causes of P0403?
The most common causes of P0403 are: Faulty EGR valve or EGR solenoid, Damaged wiring or connector in the EGR control circuit, Open or short in the EGR control wiring, Corroded or loose EGR connector, Blown fuse or lost power supply to the EGR circuit, Carbon buildup binding the EGR valve, Faulty engine control module or driver circuit. The specific cause varies by vehicle.
How much does it cost to fix P0403 on a Ford?
Published repair estimates on Ford range from $800 to $3,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0403 on a different make?
View P0403 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.