P0070
UniversalAmbient Air Temperature Sensor Circuit Malfunction
Low SeverityThis code indicates a problem with the Ambient Air Temperature Sensor circuit, which provides outside temperature readings to the vehicle's computer. A malfunction can lead to incorrect temperature displays on the dashboard or issues with the automatic climate control system.
⚠️ Before You Begin (Safety First)
Always disconnect the battery before performing any electrical work on your vehicle to prevent short circuits or injury. Allow the engine and exhaust components to cool down before handling them to avoid burns.
Common Symptoms
- Inaccurate outside temperature display on the dashboard
- Automatic climate control system not functioning correctly (e.g., blowing incorrect temperature air)
- Check Engine Light (CEL) illuminated
- Rarely, incorrect engine performance calculations (though this sensor's primary role is not engine management for most vehicles)
Common Causes
- Faulty Ambient Air Temperature Sensor
- Damaged or corroded wiring or connectors in the AAT sensor circuit
- Open or short circuit within the AAT sensor wiring
- Less common: Malfunctioning Powertrain Control Module (PCM) or Body Control Module (BCM)
Frequently reported on: General/Universal
Diagnostic Steps
- Locate the Ambient Air Temperature Sensor, often found behind the front grille, bumper, or sometimes within the side mirrors.
- Visually inspect the sensor and its electrical connector for any obvious signs of damage, corrosion, or loose connections.
- Disconnect the sensor and check the connector pins for corrosion. Clean if necessary.
- Using a multimeter, test the resistance of the sensor (refer to your vehicle's service manual for specific values) to determine if it's within specifications.
- If the sensor appears faulty or the wiring is damaged, replace the sensor and/or repair the wiring.
- Clear the P0070 code using an OBD-II scanner and re-test the system.
👨🔧 When to Call a Professional
If you have replaced the Ambient Air Temperature Sensor and the code P0070 continues to appear, or if you suspect wiring damage that is beyond a simple visual inspection, it is advisable to consult a professional technician for further diagnosis.
Commonly Asked Questions
What does the Ambient Air Temperature Sensor do?
The Ambient Air Temperature (AAT) sensor measures the outside air temperature and sends this information to the vehicle's computer, which uses it for the dashboard display and automatic climate control system.
Can a faulty AAT sensor affect my car's performance?
Typically, a faulty AAT sensor has minimal direct impact on engine performance. Its primary function is for cabin comfort and display. However, in some systems, it might indirectly influence A/C compressor operation or other minor functions.
Where is the Ambient Air Temperature Sensor usually located?
The AAT sensor is commonly found in an area exposed to outside air, such as behind the front grille, within the front bumper, or sometimes integrated into a side mirror assembly. Its exact location varies by vehicle make and model.
Is it safe to drive with a P0070 code?
Yes, generally it is safe to drive with a P0070 code. It usually indicates a problem with the temperature display or climate control, not a critical engine or safety system. However, it's best to address it to restore full functionality.
How can I test if the AAT sensor is bad?
You can test the AAT sensor using a multimeter to measure its resistance. The resistance should change predictably with temperature. Consult your vehicle's service manual for the correct resistance values at various temperatures.