An OBD2 dongle can be a valuable tool for diagnosing car problems, but sometimes, it can cause confusion. This article explores a situation where a cheap OBD2 Bluetooth dongle may have interfered with a car’s computer, triggering warning lights and a confusing error code. We’ll discuss the symptoms, troubleshooting steps, and the importance of using a reliable OBD2 scanner.
Understanding the Problem
The owner of a Chevrolet Sonic experienced a sudden issue where the power steering, traction control, and check engine lights illuminated, accompanied by extremely stiff steering. An Autozone scan revealed a single code: P069E, indicating the Fuel Pump Control Module instructed the CPU to turn on the malfunction indicator lamp (MIL). However, the car’s engine was running smoothly, and there were no other symptoms of a faulty fuel pump.
The owner suspected the issue stemmed from interference between a cheap Bluetooth OBD2 dongle and the car’s computer. This raises the question: can an OBD2 dongle trigger false error codes or even cause malfunctions?
Troubleshooting with OBD2 Scanners
Further investigation revealed that a professional-grade scan tool (Actron CP9135) successfully communicated with a different vehicle (a motorhome), ruling out a problem with the scan tool itself. However, repeated attempts to connect to the Sonic’s OBD2 system using the Bluetooth dongle resulted in link errors. This inconsistency points towards a potential compatibility issue between the dongle and the car’s system. The fact that Autozone’s scanner worked correctly further supports this theory.
Choosing the Right OBD2 Dongle
The experience highlights the importance of investing in a reliable OBD2 dongle. While budget-friendly options are tempting, they can lead to unreliable readings, connectivity issues, and potential misdiagnosis. Reputable brands like BAFX are often recommended for their consistent performance and compatibility. More expensive, professional-grade scan tools offer advanced features and greater accuracy, but may not be necessary for the average car owner.
Beyond Diagnostics: Utilizing OBD2 Data
Beyond basic diagnostics, OBD2 dongles can provide valuable real-time data, such as coolant temperature and turbo boost pressure. This information can be useful for monitoring engine performance and potentially identifying underlying issues. Some apps, like Torque Pro, offer even more extensive data points, including coolant and oil pressure, and oil temperature.
This additional data can be invaluable for troubleshooting complex problems, like a slow coolant leak. In the Sonic’s case, the owner observed a gradually decreasing coolant level in the recovery tank, despite multiple dealership inspections failing to locate a leak. Access to real-time coolant temperature and pressure data might help pinpoint the problem.
Conclusion
While an OBD2 dongle can be a powerful diagnostic tool, choosing a reliable device is crucial. A cheap or faulty dongle can lead to inaccurate readings, connectivity problems, and even trigger false error codes. If you encounter unusual car behavior after using an OBD2 dongle, consider testing with a different, reputable scanner. Investing in a quality OBD2 dongle and utilizing the data it provides can empower car owners to better understand and maintain their vehicles.
