P02E0 – Diesel Intake Air Flow Control Circuit/Open

By Bojan Popic (Contact Me)
Last Updated 2023-05-03
Master Mechanical Engineer
CodeFault LocationProbable Cause
P02E0 Diesel Intake Air Flow Control Circuit/Open
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Table of Contents

  1. What Does Code P02E0 Mean?
  2. Where is the P02E0 sensor located?
  3. What are the common causes of code P02E0?
  4. Get Help with P02E0

What Does Code P02E0 Mean?

OBD II fault code P02E0 is a generic diagnostic trouble code defined as Diesel Intake Air Flow Control Circuit/Open. It is set when the PCM detects the difference between the intake control valve’s actual and desired position. Or, to put it simply, this code is triggered when this device doesn’t open and close as the PCM would want it to.

This explanation may raise some eyebrows, as many of you know that Diesel engines don’t have a throttle body. And that is partially true because, unlike gasoline engines, the engine’s speed is controlled by the amount of injected fuel.

Many car makers, however, have recently started fitting Intake Air Flow Control devices – or throttle bodies, if you will – to their diesel engines to reduce emissions. Their job here is to work in pairs with the EGR system and improve its efficiency. When the conditions are right, this Intake Air Flow Control device partially closes, which creates a vacuum inside the intake manifold. This consequently speeds up airflow, which mixes up with gasses from the EGR system more efficiently.

Although the P02E0 trouble code is generic, this article will focus on Ford and Mazda vehicles with a 3.2-liter 5-cylinder diesel engine. This unit was used in many Transit vans, Rangers, and BT50 models manufactured from approximately 2000 onwards.

Where is the P02E0 sensor located?

The Intake Air Flow Control actuator on the said engine is fitted at the inlet side of its intake manifold, with wiring connected to it. This device looks similar to a traditional throttle body, hence the common confusion regarding its name and purpose.

These engines are usually mounted lengthways, putting the Intake Air Flow Control actuator on the driver’s side (for the left-hand-drive vehicles) of the engine bay.



What are the common causes of code P02E0?

Sticky Intake Air Flow Control Actuator
The P02E0 and codes that usually come with it, such as P02E9, are initially caused thick by carbon buildups inside the actuator. These buildups form from oily fumes from the turbocharger and the PCV system, preventing the butterfly valve inside the actuator from moving freely. Cleaning the Intake Air Flow Control Actuator can sometimes solve the problem.

Damaged Intake Air Flow Control Actuator
If the buildup issue mentioned above isn’t addressed quickly enough, the actuator’s internal mechanism may get damaged. In most cases, the plastic gear that connects the stepper motor to the butterfly’s shaft will get stripped because of excessive force. As this is not a serviceable item, the Intake Air Flow Control Actuator has to be replaced. In addition, the ECM should be updated, and the newly fitted part should be calibrated.

Wiring and connector issues
Lastly, as with most other electronic devices, the wiring may be damaged or broken. In most cases, a simple visual control could reveal if this is the case. Alternatively, you can use a multimeter to measure the resistances and voltages for each wire. Another potential cause is the connector, which may be loose and full of moisture. This causes corrosion, interrupting the communication between the actuator and PCM. Lastly, there are cases when one of the pins on the actuator itself were loose or bent, which may be caused by uncareful fitment.

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