Ford P1404 Trouble Code: Complete Guide from Diagnosis to Repair

The Ford P1404 trouble code is a generic code related to the Exhaust Gas Recirculation (EGR) system, specifically the Differential Pressure Feedback EGR (DPFE) sensor circuit. When this code appears on your diagnostic tool, it indicates a performance or circuit problem with the DPFE sensor, a key component for the proper operation of the EGR valve. Understanding this code, its causes, and the methods to resolve it is essential for any Ford owner facing rough idling or an illuminated check engine light.

What is the P1404 Code and What Does it Mean?

The P1404 code is specifically recorded when your Ford’s Powertrain Control Module (PCM) detects an abnormal voltage or an out-of-range performance signal from the Exhaust Gas Differential Pressure (DPFE) Sensor. This sensor plays a crucial role in measuring the pressure difference between the two sides of the metal orifice located in the EGR tube. This data allows the PCM to accurately calculate the EGR flow rate and effectively control the opening and closing of the EGR valve. Therefore, a Ford P1404 fault means this control loop is interrupted, preventing the system from operating optimally.

Common Symptoms of the P1404 Fault

When the P1404 code is stored in the PCM’s memory, several symptoms can alert the driver. It is important not to ignore them, as they can affect driving performance and increase fuel consumption.

• Illuminated Check Engine Light: This is the most obvious sign that the system has detected an anomaly.
• Rough or Erratic Idle: The engine may stall at idle or experience stumbling.
• Loss of Power: A feeling of sluggishness during acceleration, especially when picking up speed.
• Increased Fuel Consumption: The engine operates less efficiently.
• Increased Pollutant Emissions: As the EGR system no longer performs its function, emissions of nitrogen oxides (NOx) increase.

Main Causes of the P1404 Code on a Ford

Several factors can cause the Ford P1404 code to appear. An accurate diagnosis is necessary to pinpoint the failure and avoid replacing parts unnecessarily.

• A Faulty DPFE Sensor: This is the most common cause. The sensor itself may be damaged or providing incorrect readings.
• Electrical Circuit Problem: Damaged, corroded, loose, or shorted electrical wires leading to or from the DPFE sensor.
• Clogged or Leaking DPFE Sensor Hoses: The small rubber hoses connecting the sensor to the EGR tube can become clogged with soot or crack over time, distorting the pressure reading.
• Problem with the EGR Valve Itself: Although the code points to the sensor circuit, a faulty or clogged EGR valve can sometimes be the underlying cause.
• Rare PCM Failure: In rare cases, the control module itself may be faulty.

How to Diagnose and Repair the P1404 Fault?

The diagnostic procedure must be methodical to identify the root cause of the problem.

1. Visual Inspection

Start with a thorough inspection of the related components. Locate the DPFE sensor (often mounted on the intake manifold or nearby). Check the condition of the two small rubber hoses: are they properly connected, cracked, or clogged? Examine the sensor’s electrical connector: is it clean, properly plugged in, and free of corrosion?

2. DPFE Sensor Test

Using a multimeter, you can test the sensor. The exact procedure varies depending on the Ford model, but it generally involves checking the reference voltage (often 5V) and ground, then measuring the return signal (typically between 0.5V and 5V) at idle and while slightly accelerating. A value that does not change or is outside specifications indicates a faulty sensor.

3. Hose Inspection

Carefully disconnect the hoses from the sensor and blow through them to ensure they are not blocked. Replace them if they are damaged.

4. EGR Valve Cleaning

Even though the code relates to the sensor, it is wise to clean the EGR system. Remove the EGR valve and thoroughly clean the carbon and deposits with a specialized cleaner.

Repair

Depending on your diagnosis:

• Replace the faulty DPFE sensor (the most common solution).
• Replace cracked or clogged vacuum hoses.
• Repair or replace the damaged wiring harness.
• Clean or replace the EGR valve if necessary.

After any repair, clear the trouble code with an OBD2 scanner and perform a road test to ensure the Ford P1404 code does not reappear.

Conclusion

The Ford P1404 code, while specific, is a known issue and often simple to resolve. A logical diagnostic approach, starting with a visual inspection of the hoses and connectors, often allows for quick identification of the problem’s source. In most cases, replacing the DPFE sensor will be sufficient to restore your vehicle’s optimal performance and turn off the infamous check engine light. For less experienced mechanics, consulting a professional remains the safest solution for a definitive diagnosis.