P0073 Code

P0073 Code: Ambient Air Temperature Sensor Circuit High Input

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Unraveling the P0073 Trouble Code: Ambient Air Temperature Sensor Circuit High Input GuideMechanic.Com In the intricate realm of automotive diagnostics, trouble codes act as crucial indicators, providing valuable insights into potential issues within a vehicle’s intricate systems.

Among these codes, P0073 takes center stage, indicating a concern with the Ambient Air Temperature (AAT) sensor circuit’s high input.

Understanding the significance of this code, its underlying causes, and how to rectify it is essential for maintaining optimal vehicle performance and reliability.

See Also: P0071 Code: Ambient Air Temperature Sensor Range/Performance

P0073 Code: Ambient Air Temperature Sensor Circuit High Input

The Vital Role of the Ambient Air Temperature Sensor:

P0073 Code

The Ambient Air Temperature (AAT) sensor is a vital component in modern vehicles, providing essential data to the Engine Control Module (ECM) or Powertrain Control Module (PCM).

Situated within the vehicle’s intake air system or externally, this sensor measures the temperature of the surrounding air. This data is crucial for various engine functions, including fuel injection timing, air/fuel ratio adjustment, and emissions control.

Deciphering the Trouble Code:

The P0073 trouble code specifically denotes an issue with the Ambient Air Temperature sensor circuit’s high input. It indicates that the voltage signal received from the AAT sensor exceeds the expected threshold, deviating from predetermined parameters.

When this code surfaces, it signals to the ECM or PCM that there is a problem with the AAT sensor circuit, potentially impacting engine performance and efficiency.

Common Causes of the P0073 Code:

Several factors may contribute to triggering the P0073 trouble code:

Faulty AAT Sensor:

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P0073 Code

Over time, the AAT sensor may degrade or malfunction due to exposure to harsh environmental conditions, corrosion, or internal electrical faults.

A defective sensor may generate inaccurate temperature readings or fail to transmit data to the ECM/PCM, prompting the activation of the P0073 code.

Wiring Issues:

Damaged, corroded, or loose wiring connections within the AAT sensor circuit can disrupt the flow of electrical signals. This can result in a high voltage input to the ECM/PCM, leading to erratic temperature readings or intermittent communication between the sensor and the vehicle’s computer system, culminating in the activation of the P0073 trouble code.

Connector Problems:

Faulty connectors or poor connections between the AAT sensor and the vehicle’s wiring harness can impede electrical conductivity. Loose or corroded pins may cause voltage fluctuations or signal interruptions, triggering the P0073 code.

Environmental Factors:

Exposure to extreme temperatures, moisture, road debris, or contaminants can adversely affect the performance and reliability of the AAT sensor. Harsh environmental conditions may accelerate sensor degradation or induce electrical issues, precipitating the activation of the P0073 code.

Troubleshooting and Resolving the P0073:

Addressing the P0073 trouble code necessitates a systematic approach to diagnosis and repair:

Diagnostic Scan:

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P0073 Code

Commence by conducting a comprehensive diagnostic scan employing a compatible scan tool. Retrieve and document all stored trouble codes, including any freeze frame data associated with the P0073 code.

Visual Inspection:

Undertake a visual inspection of the AAT sensor and its surrounding components. Scrutinize for signs of physical damage, corrosion, or contamination. Examine the wiring harness and connectors for visible damage or loose connections.

Testing AAT Sensor:

Utilize a multimeter to assess the resistance and voltage output of the AAT sensor. Compare the readings to specifications provided by the manufacturer. Replace the sensor if it fails to align with the specified values.

Check Wiring and Connectors:

Inspect the wiring harness and connectors associated with the AAT sensor. Rectify or substitute any damaged wires, corroded terminals, or faulty connectors. Ensure proper routing and secure connections.

Clear Codes and Test Drive:

Upon completing repairs, clear the trouble codes from the ECM/PCM memory utilizing the scan tool. Proceed to test drive the vehicle to validate that the issue has been resolved. Monitor the AAT sensor readings and verify that they fall within the expected range.

Follow-Up Inspection:

Subsequent to driving the vehicle for a reasonable distance, conduct a follow-up inspection to confirm that the P0073 code does not resurface. Continuously monitor the sensor’s performance over time to detect any recurring issues.


In conclusion, the P0073 trouble code associated with the Ambient Air Temperature sensor circuit’s high input signifies a potential malfunction or discrepancy in the vehicle’s AAT sensor system.

Understanding the origins and implications of this code is paramount for diagnosing and remedying the underlying issues effectively.

By adhering to a systematic diagnostic approach and addressing any faulty components or wiring anomalies, drivers and technicians can uphold optimal vehicle performance and reliability.

Regular maintenance and inspection of the AAT sensor system can mitigate the likelihood of future occurrences of the P0073 trouble code, augmenting the overall longevity of the vehicle.

See Also: P0072 Code: Ambient Air Temperature Sensor Circuit Low Input


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