Code Definition

P0071 — Ambient Air Temperature Sensor Range/Performance

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0071

P0071 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0071 is stored, the module has detected a plausibility fault — the measured value is in the electrical range but is not consistent with expected operating behaviour; and a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0071 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The P0071 code indicates a problem with the range or performance of the ambient air temperature sensor. This sensor measures the external air temperature around the vehicle and provides input to the Engine Control Module (ECM) for various functions, including climate control system operations and some aspects of engine management. The ECM sets this code when it detects that the reading from the ambient air temperature sensor is out of the expected range or the sensor's performance is irregular.

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