Are you experiencing issues with your Blue Car Scanner and struggling to read diagnostic trouble codes? Many car owners are turning to affordable blue car scanners, often based on the ELM327 interface, for DIY diagnostics. These handy devices, when paired with smartphone apps, promise to reveal the hidden issues lurking beneath your car’s hood.
The original poster in our forum, a BMW 120D owner, encountered a common frustration. After their trusty old code reader gave up, they opted for a budget-friendly blue car scanner from eBay, similar to the one pictured below:
Compact Blue Bluetooth OBD2 Scanner: A budget-friendly car diagnostic tool for reading fault codes and live data, as shown on eBay.
They paired this blue car scanner with the popular Car Scanner app on their Android phone. While the scanner successfully streamed live data like acceleration and RPM, it failed to retrieve any trouble codes – even though the ABS light was illuminated, signaling a definite issue.
This situation begs the question: why might your blue car scanner be connecting and showing live data, but failing to read those crucial diagnostic codes? Let’s explore some common reasons and troubleshooting steps.
Potential Reasons Your Blue Car Scanner Isn’t Reading Codes:
- App Compatibility: While Car Scanner is widely used, it might not be fully compatible with every car model or every blue car scanner variant. Some apps are better suited for specific car brands or scanner types.
- Scanner Quality and Clones: The original poster correctly identified their eBay purchase as a “clone.” Lower-cost blue car scanners, especially clones, can sometimes have limitations in functionality or may not fully adhere to OBD2 standards. While many work perfectly well, some might have issues with code reading on certain vehicles.
- Protocol Support: OBD2 is a standard, but there are different protocols within it (like CAN, ISO, PWM, VPW). It’s possible that the blue car scanner or the app isn’t correctly communicating using the specific protocol required by the BMW for fault code retrieval, even if live data is transmitted via a more basic protocol.
- Ignition and Connection Issues: Ensure your car’s ignition is turned to the “ON” position (engine not necessarily running) when attempting to read codes. A poor connection between the blue car scanner and the OBD2 port can also lead to communication problems. Try unplugging and firmly re-plugging the scanner.
- Faulty Scanner: In rare cases, the blue car scanner itself might be faulty, specifically in its ability to read diagnostic codes, even if the Bluetooth connectivity and basic data streaming are functional.
Troubleshooting Steps and Alternative Apps:
- Verify Car and Scanner Compatibility: Double-check if the blue car scanner (specifically the ELM327 version if known) is generally compatible with your BMW model and year. Online forums and product reviews can provide insights.
- Try Alternative OBD2 Apps: If Car Scanner isn’t working for code reading, explore other free or low-cost OBD2 apps available on the Google Play Store or Apple App Store. Popular alternatives include Torque Pro (Android), OBD Fusion (iOS & Android), and BimmerCode/BimmerLink (specifically for BMW, though often with a cost involved for advanced features). Trying a different app can quickly rule out app-specific compatibility issues.
- Test on Another Vehicle (If Possible): If you have access to another OBD2-compliant vehicle, try using your blue car scanner and Car Scanner app (or an alternative app) on that car. If it reads codes on the other car, the issue is likely specific to the BMW or the scanner’s compatibility with that particular vehicle.
- Inspect the OBD2 Port: Visually inspect your car’s OBD2 port for any damage or debris that might be hindering a proper connection.
- Consider a Dedicated BMW Diagnostic Tool: If you frequently work on BMWs or need more advanced diagnostics, consider investing in a tool specifically designed for BMW vehicles. These tools often offer deeper diagnostics, BMW-specific fault code reading, and advanced functions beyond generic OBD2 scanners.
Conclusion:
While blue car scanners offer an accessible entry point into DIY car diagnostics, compatibility issues and variations in scanner quality can sometimes lead to frustrations like the inability to read trouble codes. By systematically troubleshooting and trying alternative apps, you can often pinpoint the cause. If the problem persists, especially with critical systems like ABS, seeking professional diagnostic help or considering a more specialized BMW diagnostic tool might be the most effective next step.
