What does it mean?
This is a generic powertrain diagnostic trouble code (DTC), meaning it covers all makes/models from 1996 onward. However, specific troubleshooting steps vary by vehicle.
The On-Board Diagnostic (OBD) trouble code P044E is a generic code related to an intermittent or erratic issue in the Exhaust Gas Recirculation (EGR) valve’s electrical circuit “C”.
The purpose of the EGR valve is to introduce a regulated amount of exhaust gas into the intake manifold. The goal is to keep cylinder head temperatures below 2500 degrees F. Oxygen nitrates (Nox) form when temperatures exceed 2500 degrees F. Nox is responsible for smog and air pollution.
The control computer, either the Powertrain Control Module (PCM) or the Electronic Control Module (ECM), detected an abnormally low, high, or non-existent signal voltage. Refer to a manufacturer-specific repair guide to determine what the “C” sensor is for your exact vehicle.
EGR Operating Principles
The P044E trouble code refers to the same issue across all vehicles; however, there are many types of EGR systems, sensors, and activation methods. The only similarity is that they all vent exhaust gases into the intake manifold to cool cylinder head temperatures.
Introducing spent exhaust gases into the engine at the wrong time reduces power and causes rough idling or stalling. With this in mind, the computer programming only opens the EGR when the engine speed is above 2000 RPM and closes it under load.
Related EGR “C” Sensor Fault Codes:
P044A Exhaust Gas Recirculation “C” Sensor Circuit
P044B Exhaust Gas Recirculation “C” Sensor Circuit Range/Performance
P044C Exhaust Gas Recirculation “C” Sensor Circuit Low
P044D Exhaust Gas Recirculation “C” Sensor Circuit High
Symptoms
Symptoms depend on the EGR valve’s position at the time of failure.
The service engine soon light will illuminate, and the OBD code P044E will be set. Additionally, a second code related to EGR sensor failure may be set. Code P044C relates to low sensor voltage, and P044D relates to a high voltage situation.
If the EGR valve is stuck partially open, the vehicle may not idle well or may stall.
Knocking sounds may be heard under load or at high RPM.
No symptoms at all.
Potential Causes
Faulty EGR “C” sensor.
Defect in the sensor wiring harness.
EGR valve stuck in the closed position, with carbon buildup preventing it from opening.
Lack of vacuum at the EGR solenoid.
Faulty EGR solenoid.
Faulty EGR position sensor.
Faulty EGR differential pressure feedback sensor.
Repair Procedures
All EGR valves have one thing in common: they recirculate exhaust from the exhaust to the intake manifold. Beyond that, they differ in their methods of regulating valve opening and detecting its position.
The following repair procedures represent the most common issues responsible for the majority of EGR system failures. Wiring harness or sensor failures require a service manual to determine proper wire identification and diagnostic procedures.
Keep in mind that wiring differs between manufacturers, and computers do not respond well if the wrong wire is probed. If you probe the wrong wire and send excessive voltage through the computer’s sensor input terminal, the computer may be damaged.
At the same time, if the wrong connector is unplugged, the computer could lose its programming, requiring the vehicle to be taken to a dealer to reprogram the computer.
Code P044E indicates a malfunction in the “B” circuit, so check the EGR sensor connector for corrosion, bent or pushed terminals, or loose connections. Clean any corrosion and reinstall the connector.
Remove the electrical connector and take out the EGR valve. Check for carbon buildup in the EGR’s intake and exhaust passages. Clean any carbon deposits as needed so the valve moves up and down smoothly.
Check the vacuum line from the EGR to the solenoid and replace it if defects are found.
Check the solenoid’s electrical connector for corrosion or defects.
If the vehicle is a Ford, trace the two vacuum hoses from the EGR to the Differential Pressure Feedback EGR (DPFE) sensor at the back of the manifold.
Check both pressure hoses for corrosion. Experience shows that these hoses can become clogged with exhaust carbon. Use a small pocket screwdriver or equivalent to clean the hoses of corrosion, and the sensor should resume functioning.
If the most common tests do not resolve the issue, a service manual is needed to continue testing the wiring circuits. The best solution is to take the vehicle to a service center with the appropriate diagnostic equipment. They can quickly identify and repair this type of problem.