What is the P0073 fault code?
The P0073 fault code, applicable to all car manufacturers, means “Ambient Air Temperature Sensor Circuit High“.
Background Information: The ambient air temperature sensor transmits the outside air temperature as an electrical signal to the Electronic Control Unit (ECU) to help the engine achieve the optimal air-fuel ratio. This fault code indicates that the ambient air temperature sensor signal voltage is higher than the calibrated maximum value.
Symptoms of Error Code P0073
- Incorrect outdoor temperature data on the dashboard
- Air conditioning malfunction
- Increased fuel consumption
- Delayed heating on
- Unstable air conditioning fan
Main Causes of Error Code P0073
- Temperature sensor damage or malfunction
- Open or short circuit in sensor wiring
- Console corrosion or poor contact
- Air conditioning unit error
- Front-end damage (after an accident)
How do I diagnose error code P0073?
- Connect an OBD2 diagnostic scanner and read the error code.
- Check the actual outside temperature displayed on the vehicle’s computer. If there is an obvious error, the problem is confirmed.
- Check the temperature sensor for visibly damaged or contaminated surfaces.
- Check the condition of the wiring and connectors. Use a multimeter to tap the circuit.
- If necessary, remove the sensor and test its resistance under different temperature conditions.
Possible Causes and Diagnostic Methods
| Possible Causes | How to Check? |
|---|---|
| Sensor Failure | Multimeter Resistance Test |
| Damaged Wires | Visual Inspection, Circuit Ringing |
| Poor Connector Contact | Clean Contacts, Check for Corrosion |
| Climate Electronic Failure | OBD2 Scanner Diagnostics |
Required Tools: OBD2 scanner, multimeter, contact cleaner, thermometer (for comparison readings)
How to Resolve Error Code P0073? (Solution to the Problem)
Simple Repair Method
- If random errors occur, reset the error using an OBD2 scanner.
- Clean dirt and corrosion from sensor connectors.
- Inspect and restore wiring integrity.
In-depth diagnostics and repair solutions.
- Replace faulty temperature sensor.
- Repair or replace damaged wires.
- Inspect and replace air conditioning unit (if necessary).
Troubleshooting through symptoms.
| Symptoms | Possible solutions |
|---|---|
| Temperature data error | Check and replace sensor |
| Air conditioning control malfunction | System diagnostics, wiring check |
| Fan starts unexpectedly | Clean contacts, check circuitry |
Vehicles commonly experiencing P0071 error
Ford’s P0073: Characterized by sensors often used in conjunction with exterior mirror modules. It’s easily damaged after a car wash or accident.
Hyundai’s P0073: This is common in Solaris and Elantra models. Errors can occur when moisture gets into the connector.
Toyota’s P0073: Sometimes the error is due to damage to the front bumper sensor bracket. When replacing the bumper, it’s important not to damage the wiring.
Volkswagen’s P0073: It’s usually related to a broken wire near the radiator grille. Use a moisture-sensing connector.
P0073 in Chevrolet: On Cruze and Malibu models, a sensor installed in an area prone to icing can cause a temporary malfunction.
P0073 Frequently Asked Questions
Can I drive with error code P0073?
Yes, in most cases the vehicle will function normally, but air conditioning may be interrupted and fuel consumption may increase.
Do I need to urgently fix error P0073?
Yes, especially if there is a problem with the cabin’s heating or cooling system. Clearing it prematurely will affect the comfort and operation of other systems.
Which sensor is causing the P0073 error?
This error is related to the ambient air temperature sensor, which is usually installed at the front of the car—behind the bumper or inside the side mirror.
Can I reset the P0073 code myself?
Yes, you can use an OBD2 scanner or temporarily disable the battery. However, if the cause of the problem is not resolved, the error will reappear.
Where is the ambient temperature sensor located?
In most models, it is located behind the front bumper, near the radiator grille, or inside the side mirror housing.
P0073 Related OBD2 Errors
P0070 – Ambient Air Temperature Sensor Circuit
P0071 – Ambient Air Temperature Sensor Range/Performance
P0072 – Ambient Air Temperature Sensor Circuit Low
Important! Sometimes errors are not visually apparent and are only detected during an ECU scan. However, even without symptoms, it is recommended to eliminate the problem to avoid indirect consequences. When replacing sensors, always check the condition of wiring and connectors, especially after an accident or a vigorous car wash. Don’t forget to clear the error memory after repair.