Connecting an OBDII scan tool to your Subaru and encountering an unexpected error code can be concerning. This article discusses the U0073 code, a common communication error in Subaru vehicles, specifically focusing on experiences with the OBDLink LX scan tool and the ActiveOBD app. We’ll explore potential causes, solutions, and whether this “permanent” code is something to worry about.
Understanding the OBDII U0073 Code in Subaru
The U0073 diagnostic trouble code (DTC) indicates a communication error within the vehicle’s network. This typically points to a problem with the Control Area Network (CAN) bus, the communication system responsible for transmitting data between various electronic control modules (ECMs) in the car. In a Subaru, encountering this code after using an OBDII scan tool, like the OBDLink LX, might suggest a disruption caused by the scanning process itself.
Potential Causes of a U0073 Code After Using an OBDII Scanner
While the U0073 code usually signals a communication issue, its appearance after using a scan tool, particularly with an app like ActiveOBD, raises several possibilities:
- Software Glitch: The ActiveOBD app, or the OBDLink app itself, might have encountered a software glitch during the data reading or clearing process, temporarily disrupting communication within the CAN bus.
- Incompatible App: While rare, incompatibility between the specific app (ActiveOBD) and the vehicle’s ECM could potentially trigger the U0073 code.
- Underlying Issue: The scan tool might have uncovered a pre-existing intermittent communication problem within the vehicle’s network, which was previously undetected.
Addressing the U0073 Code and Its “Permanent” Status
The “permanent” label associated with the U0073 code in the OBDLink app often causes confusion. This doesn’t necessarily indicate a permanent hardware fault. Instead, it signifies that the code was stored in the vehicle’s non-volatile memory, meaning it persists even after the code is cleared. To truly resolve the issue:
- Clear the Code: Use a reliable OBDII scan tool, like the OBDLink app, to clear the U0073 code.
- Monitor for Recurrence: After clearing the code, drive the vehicle for a period and periodically check if the code returns. If it doesn’t reappear, the initial disruption might have been temporary.
- Check for Other Symptoms: Observe if any other unusual symptoms accompany the U0073 code, such as rough idling, erratic throttle response, or warning lights. These could indicate a more serious underlying problem.
- Consult a Technician: If the U0073 code persists or other symptoms arise, consulting a qualified Subaru technician is recommended to diagnose and address any potential underlying issues within the CAN bus system.
Throttle Response Changes After Clearing the Code
Changes in throttle response, like a more “binary” or ON/OFF feel, after clearing the U0073 code, might be related to the vehicle’s electronic throttle control system re-learning its parameters. This re-learning process is often temporary and typically resolves itself after a period of driving.
Conclusion
Encountering the OBDII U0073 code on a Subaru after using an OBDII scan tool, particularly with an app like ActiveOBD, can be concerning but doesn’t always indicate a serious problem. Often, it’s a temporary communication disruption. Clearing the code and monitoring for its return, alongside observing any other symptoms, are crucial steps. If the issue persists or other symptoms develop, seeking professional diagnosis from a qualified technician is recommended.
