P0073 code definition

Ambient Air Temperature Sensor Circuit High input

Depending on the type of vehicle these are some related OBD-II Diagnostic Trouble Codes:

  • P0070: Ambient Air Temperature Sensor Circuit
  • P0071: Ambient Air Temperature Sensor Range/Performance
  • P0072: Ambient Air Temperature Sensor Circuit Low Input

What the P0073 code means

The Power Control Module (PCM) uses information that it receives from the ambient air temperature sensor to regulate the levels of the ambient air temperature and intake air temperature.

If the ambient air temperature reaches a level above that of the intake air temperature, the Power Control Module (PCM) will store the P0073 trouble code and the Check Engine Light will come on.

What causes the P0073 code?

There are several things that could cause the P0073 trouble code to be stored by the Power Control Module (PCM):

  • The ambient air temperature sensor has malfunctioned
  • The wiring has shorted or broken
  • There is corrosion in the electric circuitry or connector
  • A break or short in the ambient air temperature harness
  • Debris that is covering the sensor

What are the symptoms of the P0073 code?

The biggest indication of a problem with the ambient air temperature system is that the Check Engine Light is on. In certain cases, the climate control system (heat and/or air condition controls) will not work as they should.

How does a mechanic diagnose the P0073 code?

  • Freeze frame data and trouble codes are recorded using an OBD-II scanner.

  • Next, the ambient air temperature sensor’s electrical circuitry and its connector should be inspected for bare wires, shorts or opens in the wires, and corrosion. Anything possibly covering the ambient air temperature sensor should be removed as well. If necessary, repair or replace any of these components.

  • The P0073 trouble code should be cleared and the a test drive of the vehicle should be conducted a test drive to see if the trouble code returns.

  • If the trouble code does not return, the repair is complete. In the event that the trouble code returns immediately, the ambient air temperature sensor needs to be replaced.

  • If the trouble code doesn’t come back immediately, but still returns, this could be an indication of an intermittent problem regarding the voltage leading to the Power Control Module (PCM). If this is the case, more extensive diagnosis would be required.

  • In the unlikely event that none of these measures have resolved the ambient air temperature sensor problem and cleared the P0073 code, it is possible the there is a problem with the Power Control Module (PCM). This is extremely rare.

Common mistakes when diagnosing the P0073 code

It is common for the ambient air temperature sensor to be replaced without first inspecting the wiring and connector for defects. It is not always necessary to replace the entire ambient air temperature sensor.

How serious is the P0073 code?

The P0073 trouble code is not considered to be one that is serious, as it does not affect the drivability or functioning of the vehicle. This may, however, be one that causes the driver to be uncomfortable as it could prevent the climate control system (heat and/or air condition controls) from working as they should.

What repairs can fix the P0073 code?

  • Repair or replace wires that have shorts or breaks in them
  • Absolve the electric circuitry and connector from any possible corrosion
  • Replace the ambient air temperature sensor

Additional comments for consideration regarding the P0073 code

It is important to inspect the wires and connector for damage or defects before replacing the ambient air temperature sensor.

Need help with a P0073 code?

YourMechanic offers certified mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

This article originally appeared on YourMechanic.com as P0073 OBD-II Trouble Code: Ambient Air Temperature Sensor Circuit High input and was authored by Jamahl Walker.


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