Mitsubishi 380 P0073: Meaning, Causes, & How to Fix | Automotive Help

Mitsubishi 380 P0073: Meaning, Causes, & How to Fix

Mitsubishi 380 P0088

P0073 is a common OBD2 trouble code that can affect the Mitsubishi 380. OBD2 trouble codes. In layman’s terms, it indicates that there is an issue with your car’s ambient air sensor.

The ambient air temperature sensor (or AAT for short) is responsible for monitoring outside air temperature and regulating your vehicle’s automatic climate control system.  It doesn’t affect the way your car runs or drives at all.

While P0073 is a generic code (it has the same meaning for all vehicles made after 1996), repair steps will vary depending on your Mitsubishi 380’s model year and equipped options.

P0073 Quick Info

Meaning Ambient Air Temperature Sensor Circuit – High Input
Typical Symptoms No A/C, No Outside Temperature Display
Likely Causes Bad AAT Sensor or AAT Wiring
Breakdown Risk No
Repair Difficulty Usually Pretty Easy


P0073 Code Diagnosis Mitsubishi 380

The Diagnostic trouble code (DTC) P0073 stands for “Ambient Air Temperature Sensor Circuit High Input.”

  • P: Powertrain
  • 0: Generic Code Type
  • 0: Sub-System
  • 73: Specific Malfunctioning Identifier

Here’s the definition of P0073 for the Mitsubishi 380 broken down into its two main parts:

1. Ambient Air Temperature (AAT) Sensor

P0073 Meaning
A typical AAT Sensor

The AAT sensor measures the air temperature outside of the car’s cabin. It converts this signal to a voltage value the Powertrain Control Module (PCM) can read.

Depending on your 380’s model year and options, the AAT’s only function may be to display the outside air temperature.

If your particular vehicle is equipped with a climate control system that automatically adjusts itself, it can affect the cabin air temperature (particularly when the auto start function is engaged).

2. Circuit High

The voltage value being returned by the AAT is too high in relation to the voltage value of the Intake Air Temp sensor and/or the Engine Coolant Temp sensor. These three should be within a few degrees of one another if your 380 is completely cold.

P0073 Symptoms: Mitsubishi 380

Here are the most common symptoms associated with P0073 in the Mitsubishi 380:

  • Malfunction Indicator/Check Engine Light has lit up
  • Air Conditioning may not work
  • The instrument cluster (dashboard) may not display the correct outside temperature
  • The overhead compass/console may not display the correct outside temperature

P0073 Causes + Diagnosis: Mitsubishi 380

P0073 Causes and Fix

There are really two main causes of P0073 in the Mitsubishi 380. Either the AAT is bad, or there is a problem with the wiring harness going to it.

  • Malfunctioning ambient air temperature sensor
  • Faulty Powertrain Control Module (Not very common)
  • A damaged or corroded electrical connector
  • Damage to the AAT sensor signal circuit

Most of the time, P0073 is going to be caused by a bad AAT sensor or AAT sensor wiring.

On most vehicles, the AAT sensor can be found around the front grill or bumper. Here’s a good order to go about diagnosing P0073 in your car.

1. Check the AAT Wiring

You should start by looking at your 380’s Ambient Air Temperature (AAT) sensor, connection, and wires.

If the AAT wiring harness is damaged (which frequently happens due to its location), repair it and see if that clears the code.

You can read these things using a Digital Volt-Ohm Meter (DVOM) and a thermometer. Check the vehicle manual for proper readings, and if they differ significantly from your readings, replace the sensor.

You can find the correct readings inside or very close to the front bumper.

2. Check the AAT Sensor Itself

Now that you’ve checked your 380’s AAT wiring, it’s time to check the sensor itself.

Follow through with and eliminate any other error codes before focusing on P0073. Examine the sensor itself to ensure it doesn’t look physically damaged.

In some cases, repositioning or cleaning out the terminals is the solution, but typically the culprit is a connection issue or bad sensor, whether it’s exposed or burnt wires. 

It’s likely you’ll need to replace the sensor itself, which is usually around $20 or so.

How Serious is a P0073 Code?

P0073 should not be considered a breakdown risk in the Mitsubishi 380.

This code will not affect the engine, steering, brakes, fuel consumption, or your car’s overall ability to go from point A to point B.

What it will cause, is an inconvenience. The lack of air conditioning and the inability to read the outside temperature could become a major nuisance for those located in areas with hotter climates.

The number one thing P0073 affects is the auto start features climate control. If it’s hot out, the A/C will kick on. If it’s cold, the PCM will activate the heater. Most vehicles still allow you to manually control the A/C if there is an issue.


Replacing the AAT sensor will likely clear P0073 in the Mitsubishi 380, but checking the wiring harness for damage first can save time and aggravation.

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