P044A: EGR Sensor C Circuit

Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. What EGR sensor C is depends on the maker: on Ford petrol engines from 2020 it is the DPFE sensor, which measures the pressure drop across an orifice in the EGR pipe (sensor A there is the valve position sensor); GM diesels assign it to the position sensor of a low-pressure EGR valve, but only within fault groups. P044A is the general circuit fault of this sensor. No manufacturer document available to us uses it – Ford splits it into P044C/P044D – so the description follows CARB's requirement to check input circuits for continuity and range. Without the sensor, EGR flow and cooler checks are suspended.

Symptoms

• Check engine light on
• Usually no change in driving
• EGR readiness not set, EGR possibly switched off

Most likely causes

• Connector or wire to sensor C open or corroded
• Sensor faulty
• 5 V reference or ground disturbed (with other sensor codes)
• Engine module

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the connector and any vacuum hoses
2. Use live data to compare the commanded opening with the actual opening
3. Clean the valve and passages if they are clogged with carbon
4. Test the actuator with the scanner
5. Replace the valve if it still does not follow the command after cleaning

Good to know

• Repair difficulty: easy
• It affects emissions.

What each character of P044A means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 4: Emissions
• 4A: Specific fault in that system

Frequently asked questions

Can I keep driving with code P044A?

You can normally drive in moderation, but get it repaired soon: if the valve is stuck open, the engine may idle very poorly.

What causes code P044A?

The most common causes are: connector or wire to sensor C open or corroded; sensor faulty; 5 V reference or ground disturbed (with other sensor codes).

Related codes

• P044BEGR Sensor C Circuit Range/Performance
• P044CEGR Sensor C Circuit Low
• P044DEGR Sensor C Circuit High
• P044EEGR Sensor C Circuit Intermittent/Erratic
• P0409EGR Sensor A Circuit

Sources

• law.cornell.edu: 13 CCR 1968.2
• fordservicecontent.com: OBD Operations Summary Gasoline 2020 2023
• gsi.ext.gm.com: 18OBDG04 Engine Diagnostics

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.