P2172 Code: Throttle Actuator Control System – Sudden High Air Flow Detected

Most modern vehicles come equipped with an electronic throttle actuator control system. This system includes throttle position (TP) sensors, an electronic throttle actuator, and accelerator pedal position (APP) sensors.

Like any other part of your vehicle, the throttle actuator control system can develop faults. Code P2172 indicates the vehicle’s onboard electronics have detected unexpected air flow entering or bypassing the system.

What Does the P2172 Code Mean?

Diagnostic trouble code (DTC) P2172 stands for “Throttle Actuator Control System – Sudden High Air Flow Detected.”

Vehicles that use drive-by-wire throttle control systems can log this code.

The electronic throttle control system (ETCS) controls throttle valve movement. The powertrain control module (PCM) receives a signal from the APP sensor when the driver depresses the accelerator pedal. The signal indicates how much power the engine needs to operate. The PCM adjusts the throttle plate accordingly.

When the PCM detects  unexpected high air flow entering or bypassing the ETCS (from a vacuum leak, etc.), it will set the P2172 code.

Note: The definition of code P2172 might be different depending on the vehicle manufacturer. Consult the appropriate repair manual or online repair database for the exact code definition.

What are the Common Causes of the P2172 Code?

• Vacuum leaks
• Bad manifold absolute pressure, throttle position, or accelerator pedal sensor
• Circuit problems, such as a damaged wire or poor connection
• Internal engine failure
• An issue with the PCM

What Are the Common Symptoms of the P2172 Code?

• Illuminated check engine light
• “No start” condition
• Low or no throttle response
• Incorrect idle speed

How to Diagnose the P2172 Code

The P2172 code is a generic code that different vehicles can log. However, this does not mean that there is a universal solution to determining its underlying problem.

The steps for diagnosing this code can differ depending on the vehicle’s make and model. It’s best to leave the job to a professional. But if you’re confident that you can do it yourself, consider checking out this video to get an idea of what the diagnostic process might involve:

How to Fix the P2172 Code

The repair process for the P2172 code varies, depending on the vehicle’s make and model. For example, the repair steps for a P2172 code in a Jeep might differ from the steps that will fix the same code in a Dodge.

If you’re an experienced automotive DIYer and you want to fix the issue yourself, consult a vehicle-specific repair manual or an online repair database before you get started. Alternatively, you can leave the job to a professional.