Error Code P0073
Moderate Issue
DTC Code P0073 indicates a high voltage issue in the Ambient Air Temperature Sensor Circuit, detected when the ECM finds the sensor signal below -40°C (-40°F).
What symptoms indicate Error Code P0073?
- Engine Light ON: The check engine light or service engine soon warning light illuminates on the dashboard. This is a direct indication of a fault in the ambient air temperature sensor circuit, potentially due to high voltage.
- Inaccurate Temperature Readings: The vehicle's temperature display may show incorrect ambient air temperature readings, which can affect climate control and engine performance.
- Poor Fuel Efficiency: The engine control unit (ECU) may receive incorrect temperature data, leading to suboptimal fuel mixture adjustments and reduced fuel efficiency.
What causes OBD code Error Code P0073?
- The ambient air temperature sensor may be malfunctioning, leading to incorrect voltage readings.
- An open or shorted harness in the ambient air temperature sensor can disrupt the circuit, causing high voltage issues.
- Poor electrical connections in the sensor circuit can result in intermittent or incorrect voltage signals.
- A faulty Engine Control Module (ECM) might misinterpret sensor data, leading to erroneous high voltage readings.
How to fix OBD code Error Code P0073?
- Verify DTC Code: Confirm the presence of DTC P0073 using an OBD-II scanner. Ensure no other related codes are active.
- Inspect Ambient Air Temperature Sensor: Locate the ambient air temperature sensor, typically found near the front bumper or grille. Check for physical damage or disconnection.
- Check Sensor Wiring: Inspect the wiring and connectors for corrosion, damage, or loose connections. Ensure the wiring harness is intact and properly connected.
- Measure Sensor Voltage: Using a multimeter, measure the voltage at the sensor connector. A high voltage reading indicates a potential short to power or a faulty sensor.
- Test Sensor Resistance: Disconnect the sensor and measure its resistance. Compare the reading to the manufacturer's specifications to determine if the sensor is faulty.
- Inspect ECM/PCM: Check the Engine Control Module (ECM) or Powertrain Control Module (PCM) for any signs of malfunction or damage that could affect sensor readings.
- Perform System Reset: After repairs, clear the DTC code and perform a test drive to ensure the issue is resolved and the code does not return.