What does error code P0071 mean?
The P0071 fault code, applicable to all car manufacturers, stands for “Ambient Air Temperature Sensor Range/Performance.”
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 a problem with the ambient air temperature sensor signal circuit.
Symptoms of Error Code P0071
- Incorrect temperature reading on the dashboard
- Inadequate climate control
- Diagnostic scanner error
- Reduced heating/cooling system efficiency
- Increased fuel consumption (in rare cases)
Main Causes of Error Code P0071
- Damaged or contaminated temperature sensor
- Damaged wiring or sensor connector
- Ground fault or sensor circuit fault
- ECU malfunction
- Error after installing a non-original sensor
How to Diagnose Error Code P0071?
- Read the error code using an OBD2 scanner.
- Inspect the temperature sensor and its wiring.
- Check the sensor’s resistance at different temperatures.
- Check the connectors for corrosion or contamination.
- Reset the fault code, clean/replace, and re-inspect.
Possible Causes and Diagnostic Methods
| Possible Causes | How to Check? |
|---|---|
| Temperature sensor damage | Visual inspection, multimeter resistance check |
| Contact corrosion or contamination | Clean the connectors, check for oxidation |
| Broken wire | Check circuit continuity, beeping |
| Circuit closure | Voltage measurement, short circuit search |
| ECU fault | Comprehensive diagnosis, replace if necessary |
Required tools: OBD2 scanner, multimeter, contact cleaner, heat source (for sensor testing)
How to resolve error code P0071? (Solutions to the Problem)
Simple Repair Methods
- Clean sensor connectors and contacts
- Reset error after cleaning
- Replace connector if loose
- Reconnect sensor if loose
In-depth Diagnostics and Repair Solutions
- Replace ambient air temperature sensor
- Repair or replace damaged wires
- Inspect and replace ECU (as a last resort)
- Re-flashing control unit (if necessary)
Troubleshooting Through Symptoms
| Symptoms | Possible Solutions |
|---|---|
| Non-operating climate control | Sensor replacement, wiring check |
| Dashboard display error | Circuit check, screen reset, AAT replacement |
Vehicles with Most Common P0071 Errors
Ford P0071: Error characteristics for this brand: Ford vehicles’ temperature sensors may be installed inside the radiator grille, making them susceptible to mechanical damage or contamination. Errors often occur after washing or in winter.
Volkswagen P0071: Error characteristics for this brand: In Volkswagen models, the problem usually lies in unstable contacts or connectors, especially in higher mileage models. Diagnosis requires contact with the front of the vehicle.
Audi P0071: Characteristics of this brand’s error: The error may be accompanied by other climate-related errors. Sometimes it’s because the sensor wasn’t moved when the bumper was replaced.
BMW P0071: Characteristics of this brand’s error: In BMWs, the problem is usually related to an internal short circuit in the sensor. This could also be related to a calibration error in the air conditioning control unit.
Chevrolet P0071: Characteristics of this brand’s error: In Chevrolet models, the sensor can be used in combination with other sensors; a failure in a single component can affect the entire chain.
P0071 Frequently Asked Questions
Is it possible to drive with an error P0071?
Yes, in most cases, a trip with an error P0071 is safe, but it can affect air conditioning operation and increase fuel consumption.
Where is the ambient temperature sensor located?
It’s usually located at the front of the car—behind the radiator grille, on the bumper, or next to the air conditioning radiator.
Do I need to replace the sensor when an error occurs?
Not necessarily. First, you should check the connector, clean the contacts, and measure the resistance. If the problem persists, replace the sensor.
Can the P0071 error be caused by weather conditions?
Yes, especially in winter—ice, moisture, or road residue can damage the connector or the sensor itself.
Can you reset error P0071 yourself?
Yes, you can use an OBD2 scanner or temporarily disable the battery. However, the error will reappear if the cause is not addressed.
Related OBD2 Errors for P0071:
P0070 – Ambient Air Temperature Sensor Circuit
P0072 – Ambient Air Temperature Sensor Circuit Low
P0073 – Ambient Air Temperature Sensor Circuit High
Important! The P0071 error may only occur during scanning without obvious symptoms. However, it can also affect other systems, especially in cold or hot climates. If the error occurs intermittently, first visually inspect and clean the connector. In most cases, this is sufficient to fix the fault without replacing parts.