Ford F150 P1408 Code: Understanding and Solving the Problem

The Ford F150 P1408 trouble code is a specific electronic issue related to the Exhaust Gas Recirculation (EGR) system. More precisely, this code indicates a circuit or performance problem with the Differential Pressure Feedback EGR (DPFE) sensor. When this code illuminates on your dashboard, it signals that the Powertrain Control Module (PCM) has detected a DPFE sensor voltage that is outside the normal operating range. Understanding this code, its causes, and its solutions is essential for maintaining the performance and longevity of your pickup truck.

What is the P1408 Code and Why Does It Appear?

The EGR system in your Ford F150 is designed to reduce nitrogen oxide (NOx) emissions by recirculating a small amount of exhaust gas back to the intake manifold. The DPFE sensor is a key component of this system. It measures the differential pressure of the gases flowing through the EGR tube orifice and sends an electrical signal (a voltage) to the PCM. If the PCM receives a signal that is too low (close to 0 volts) or too high (close to 5 volts) for a determined period, it will log the Ford F150 P1408 trouble code, illuminate the Malfunction Indicator Lamp (MIL), and may put the engine into a “limp mode.”

Main Causes of the P1408 Code on a Ford F150

Several factors can be the origin of this fault. It is crucial to proceed by elimination to identify the exact source of the problem.

• A Faulty DPFE Sensor: This is the most common cause. The sensor itself may be malfunctioning and sending an incorrect signal to the PCM.
• Clogged or Deteriorated DPFE Sensor Hoses: The two small rubber hoses connecting the DPFE sensor to the EGR tube can become clogged with soot, crack, puncture, or come loose, thereby distorting the pressure reading.
• Electrical Circuit Problems: These can include poor connections, cut, shorted, or corroded wires between the sensor and the PCM, or a bad ground.
• A Clogged EGR Recirculation Tube: Although less direct, heavy fouling of the EGR system can indirectly affect the DPFE sensor readings.

How to Diagnose and Repair the P1408 Fault?

Before replacing expensive parts, follow these diagnostic steps.

1. Visual Inspection: Start by locating the DPFE sensor (usually mounted on the intake manifold or nearby). Carefully inspect the two small rubber hoses. Check that they are properly connected, without cracks, and that they are not obstructed. Also, inspect the sensor’s electrical connector for any signs of corrosion or damage.

2. DPFE Sensor Test: Using a digital multimeter, you can measure the sensor’s signal voltage. With the ignition on (engine off), the voltage should typically be around 0.6-0.7 volts. At idle, this voltage should increase (often between 1.0 and 1.5 volts) when the EGR system is activated. A voltage that does not change, remains stuck at 0V or 5V indicates a faulty sensor.

3. Cleaning or Replacement: If the hoses are clogged, you can try cleaning them with a suitable product. If they are damaged, replace them. If the sensor is faulty, replacing it is the solution. Be sure to use a quality part to ensure the longevity of the repair.

Consequences and Precautions to Take

Although your Ford F150 may seem to drive normally with an active P1408 code, this fault should not be ignored. An EGR system that is not functioning properly can lead to increased pollutant emissions, power loss, less efficient combustion, and, eventually, damage to the catalytic converter. It is recommended to address this issue as soon as possible to avoid more costly repairs.