P02FA Trouble Code Solution: Decoding, Causes, Reset

The P02FA error code reads “Diesel intake air flow sensor min / max stop malfunction.” Often, in programs working with an OBD-2 scanner, the name may have the English spelling “Diesel Intake Air Flow Position Sensor Minimum / Maximum Stop Performance”.

Technical description and explanation of the P02FA code

When the PCM detects a problem in the diesel intake air flow control system, it sets a code P02FA. In this case, the code is set when a malfunction of the minimum / maximum position stop of the sensor in the air flow control system is detected.

The diesel intake air flow position sensor (DIAFPS) is usually bolted to the throttle body. It monitors the amount of incoming air flow by changing the signal to the engine controlled by the powertrain control module (PCM).

The engine opens and closes the throttle valve, which regulates airflow.

The PCM knows how much clean filtered air is entering the engine based on the diesel engine intake air position sensor, also known as the MAF sensor. When the airflow control system is activated, the PCM should notice a change in airflow.

The amount of air passing through the intake manifold is controlled by the intake air valve on the throttle body. The intake air position sensor tells the engine control module (PCM) the position of the intake air control valve of the diesel engine.

P02FA is set when a min / max stall sensor malfunction is detected in the intake air flow monitor of a diesel engine. This can happen due to mechanical damage to the system itself, which causes electrical failure or electrical problems with the circuit.

Malfunction symptoms

The main symptom of a P02FA error for a driver is a MIL (Malfunction Indicator Light) illuminated. It is also called Check engine or simply “check is on”.

They can also manifest as:

  1. The control lamp “Check engine” on the control panel will light up (the code will be written into memory as a malfunction).
  2. Low idle speed possible.
  3. The exhaust gas recirculation (EGR) system is not working.
  4. Failure to regenerate the particulate filter to burn off soot deposits.
  5. Decreased engine power.
  6. Increased fuel consumption.

The P02FA code is not considered a serious error, however, like any problem, it is recommended that you fix it. In most cases PCM can compensate for an electrical problem if there are no other sensors in this reference circuit.

Reasons for the error

The P02FA code may mean that one or more of the following problems have occurred:

  • Defective inlet air position sensor on diesel engine.
  • Damaged or worn sensor connector.
  • Damaged, burnt, shorted, disconnected, or corroded wiring.
  • Sometimes the cause is a faulty PCM.

How to eliminate or reset the P02FA trouble code

Some suggested steps to troubleshoot and fix the P02FA error code:

  1. Connect the OBD-II scanner to the vehicle diagnostic socket and read all stored data and error codes.
  2. Clear the error codes from the computer memory and test drive the vehicle to see if the P02FA code appears again.
  3. If the code reappears, check the wiring and associated connectors leading to the inlet air position sensor of the diesel engine. Make sure they are not broken or frayed. Repair or replace as necessary.
  4. Inspect and test the diesel inlet air position sensor, replace if necessary if damaged.
  5. If the cause is a faulty PCM, replace or reprogram it.

Diagnostics and problem solving

Inspect for any visible damage to the sensor, wiring, and connectors. Then start the diagnostic procedure using the scanner. To determine if the P02FA error is the only one, if not, it may be worthwhile to deal with other DTCs first.

If no problem is found with damaged or corroded connectors, perform a thorough inspection of all associated wiring. Repair or replace damaged wiring as needed.

Checking the wiring and intake air position sensor

If no visible damage to the wiring is found, prepare to perform the voltage reference, grounding, resistance, and continuity tests. Be sure to disconnect the sensor from the wire harness to avoid damaging the PCM and avoiding a short circuit.

If the P02FA code returns, the diesel intake air position sensor and associated circuits must be checked. With the engine off, disconnect the sensor electrical connector.

Connect the black lead from the DVM to the ground terminal on the harness connector of the intake air position sensor. Connect the red lead of the DVM to the signal terminal of the sensor harness connector.

Check the manufacturer’s specifications, the voltmeter should read 5 volts. If not, you need to pay attention and repair the signal wire or ground wire, or replace the PCM.

If the previous check was successful, but the P02FA error remains, most likely the sensor itself is faulty. A defective PCM cannot be ruled out before replacing the sensor, though.

If you are not sure about the actions you are taking, seek help from a qualified technician. For correct installation, the PCM needs to be programmed or calibrated for a specific vehicle.

On what cars does this problem occur more often?

The problem with the P02FA code can occur on different machines, but there are always statistics on which brands this error is more common. Here is a list of some of them:

  • Chevrolet
  • Dodge
  • Ford (Ford Kuga, Transit, Focus)
  • GMC

Other errors can sometimes be found with DTC P02FA. The most common are the following: P02EB, P02EC, P02ED.

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