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P0072 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


DTC stands for Diagnostic Trouble Codes, which are standardized systems used by vehicles to communicate and identify possible problems. This DTC code is associated with an Ambient Air Temperature Sensor Circuit’s Low Input, P0072.


According to the P0072 code, a low input signal to the vehicle’s computer is provided by the Ambient Air Temperature AAT sensor circuit. The measurements of air temperature within the vehicle are carried out by an AAT sensor. The sensor provides an accurate external temperature reading, thus helping to improve performance and fuel efficiency for a variety of systems like the engine’s air-fuel mixture.


Several factors can contribute to the activation of the P0072 code, including:

  • Faulty Ambient Air Temperature Sensor: A malfunctioning or defective AAT sensor can generate a low input signal, leading to the activation of the P0072 code.
  • Wiring Issues: Damaged or corroded wiring, loose connections, or short circuits in the AAT sensor circuit can result in a low input signal.
  • Sensor Placement: Incorrect installation or exposure of the AAT sensor to external elements may impact its performance, leading to a low input signal.
  • Problems with the electronic control module ECM: The interpretation of signals from AAT sensors may be affected by malfunctions in the vehicle’s main computer such as its emergency management system, which could result in a P0072 code.


When the P0072 code is triggered, several symptoms may manifest, including:

  • Illuminated check engine light, including P0072: a typical indicator of the issue code is the activation of the illuminated check engine light. 
  • Unreliable readings of the external temperatures: The vehicle’s display may show an incorrect or unusual reading of the exterior temperature.
  • Engine Performance Issues: Depending on the severity of the problem, you may experience reduced engine performance, decreased fuel efficiency, or other drivability concerns.


To accurately diagnose the P0072 code, it is advisable to follow these steps:

  • OBD II Scanner: In order to retrieve the problem codes and any related codes stored on your vehicle’s computer, you will need an OBD II scanner which is operated by a professional automotive technician. 
  • Visual Inspection: In order to identify the apparent signs of damage, corrosion, or loose connections, an exhaustive inspection will be carried out on AAT sensors and their interconnections.
  • Sensor testing: using a multimeter or specialized tools, the technician shall test the resistance, voltage, and temperature of the AAT sensor. 
  • Circuit testing: For continuity, short circuits, or open circuits, the wire and circuitry of the AAT sensor shall be examined.
  • ECM Analysis: In order to determine whether any additional issues contribute to the activation of the code, the data from the ECM shall be analyzed if necessary.

Common mistakes

Common errors that could result in erroneous repairs or misdiagnosis should be avoided when interpreting the P0072 code: 

Neglecting essential checks: Before moving on to more detailed diagnostic tests, routine checks should be carried out that include checking for the correct connection and fixing wires where they have been broken.

Ignoring related code: valuable information on a given problem can be obtained from associated codes stored in the ECM. Failure to comply with these codes will result in an incomplete repair. 

Missing OEM recommendations: In order to achieve the correct and efficient resolution of P0072 codes, it is important to take into account the manufacturer’s instructions on diagnostics, repairs, and replacement parts.

How serious is this?

The specific circumstances and vehicle design are of paramount importance when it comes to the P0072 code. While it may be an initial inconvenience, for example, inaccurate temperature readings, the failure to address this issue could result in suboptimal engine performance, low fuel efficiency, and possible damage to other components. It is advised that this code should be addressed promptly, in order not to introduce any additional complications.

What repairs can fix the code?

repair manuals

Once the root cause of the P0072 code is identified, the following repairs may be necessary:

  • AAT sensor replacement: When the AAT sensor is malfunctioning or missing, it should be replaced with a new, reliable sensor that will solve the problem of insufficient input signal. 
  • Wiring Repair: Repairing damaged or corroded wires, ensuring proper connections, or replacing the wiring harness may be required to restore the sensor’s performance. 
  • ECM repair or replacement: It may be necessary to repair or replace the computer in rare cases where the ECM causes the problem.

Related codes

There are several related codes that may be associated with the P0072 code, including:

  • P0070: Ambient Air Temperature Sensor Circuit Malfunction
  • P0071: Ambient Air Temperature Sensor Range/Performance
  • P0073: Ambient Air Temperature Sensor Circuit High Input

These related codes may provide additional insights into the underlying issue and assist in the diagnostic process.


To diagnose and fix problems with your vehicle, it is important to know the P0072 DTC code of an Ambient Air Temperature Sensor circuit that has a low input. You will be able to perform an effective inspection of this code because you can understand its meaning, causes, symptoms, diagnosis methods, common errors, seriousness, possible repairs, and related codes.

If you have encountered a P0072 code, or if you are concerned that the AAT sensors may be malfunctioning, it is recommended to consult an expert car mechanic.  In particular, in unpredictable weather conditions, a timely diagnosis and proper repair will help to guarantee your car’s optimum performance and reliability.

P0072 Code – What Does It Mean & How To Fix It