Troubleshooting BAFX OBD2 Bluetooth Connection Issues on a 1999 Miata

Encountering difficulties connecting your BAFX OBD2 Bluetooth adapter to your 1999 Miata can be frustrating. Many Miata owners, especially those with the NB generation (1999-2005), have reported similar issues when trying to use Bluetooth OBD2 readers. This guide will walk you through troubleshooting steps and provide instructions to help you establish a connection, specifically focusing on using a BAFX OBD2 adapter with your 1999 Miata.

Understanding OBD2 Compatibility and Your 1999 Miata

The 1999 Miata (NB Miata) is equipped with an OBD-II (On-Board Diagnostics II) system, which is the standardized system for vehicle diagnostics in the United States starting from 1996. Therefore, in theory, any OBD2 compliant reader, including Bluetooth adapters like the BAFX OBD2, should work with your vehicle. However, real-world experiences sometimes differ due to various factors such as protocol variations, adapter compatibility, and even the specific app being used.

Locating the OBD2 Port in Your 1999 Miata

The OBD2 port in a 1999 Miata is indeed located near the driver’s side fuse box. To access it, you’ll need to remove the fuse box cover, typically found to the left of the driver’s left knee. The OBD2 connector is situated above the fuses. This is the standard OBD2 port location for your vehicle, and you are using the correct plug.

While your mechanic might have appeared to access a port lower in the footwell, it’s more likely they were simply maneuvering for a better angle or using a diagnostic tool with a longer cable. Rest assured, the port behind the fuse box cover is the primary and correct OBD2 port for your 1999 Miata.

Using this port with a Bluetooth adapter for real-time monitoring, like with apps such as Torque or Car Gauge Lite, can be slightly inconvenient due to its location. However, for diagnostic purposes and occasional use, it is perfectly functional.

Step-by-Step Instructions and Troubleshooting for BAFX OBD2 Bluetooth Connection

If you’re experiencing a “No Response from Vehicle ECU” error with your BAFX OBD2 reader and your 1999 Miata, follow these steps to troubleshoot the connection:

1. Verify Basic Setup:

   • Adapter Power: Ensure the red light on your BAFX OBD2 adapter illuminates when plugged into the OBD2 port. This indicates the adapter is receiving power.
   • Bluetooth Pairing: Confirm you have correctly paired your Android device (e.g., Samsung Galaxy Player 5.0) with the BAFX adapter using the PIN code ‘1234’. Check your device’s Bluetooth settings to ensure the BAFX adapter is listed as a paired device.
   • App Configuration:
     • Select OBD2 Protocol (If Manual Option Available): While “Auto” protocol detection should ideally work, some vehicles respond better when a specific protocol is selected. In your Torque or Car Gauge Lite app settings, explore if there’s an option to manually select an OBD2 protocol. For a 1999 Miata, you can try the following if available:
       • ISO9141-2
       • ISO14230-4 (KWP2000)
     • Adapter Selection in App: Within your chosen app’s settings (Torque or Car Gauge Lite), ensure you have selected the correct Bluetooth device (your BAFX adapter) as the OBD2 adapter source.

2. Engine Running vs. Engine Off:

   • Try Both Scenarios: You’ve already tested with the engine both running and off, which is good. However, re-test specifically with the engine running, as some OBD2 functions and data might only be accessible when the engine is on.

3. Test with a Different Vehicle (Already Done – Civic):

   • Confirmation of Adapter Functionality: You’ve confirmed the BAFX adapter works correctly with your 1998 Civic. This isolates the issue to the Miata or the combination of the adapter and the Miata.

4. App Compatibility and Alternatives:

   • App-Specific Issues: While Torque and Car Gauge Lite are popular OBD2 apps, there’s a possibility of app-specific compatibility issues.
   • Try Alternative Apps: Consider testing with other OBD2 apps available on the Google Play Store. Some popular alternatives include:
     • OBD Auto Doctor
     • DashCommand
     • InCarDoc (ELM327 OBD2 Scanner)
   • Free vs. Paid Apps: Test with both free and paid versions of apps, as sometimes paid versions offer broader compatibility or advanced features that might resolve connection issues.

5. BAFX Adapter Specific Issues and Firmware (Less Likely but Possible):

   • Firmware Updates (If Possible): BAFX, as a brand, might have firmware updates for their adapters, although this is less common for basic Bluetooth OBD2 readers. Check the BAFX website or product documentation to see if firmware updates are available and how to apply them.
   • Adapter Defect (Less Likely): While your adapter works on the Civic, there’s a very slight chance of a nuanced incompatibility or defect that only manifests with the Miata.

Considering Alternative OBD2 Readers

If you’ve exhausted the troubleshooting steps above and still cannot establish a connection between your BAFX OBD2 adapter and your 1999 Miata, it might be necessary to consider alternative OBD2 readers.

• Brand and Model Variation: Different brands and models of OBD2 readers can have varying levels of compatibility with specific vehicle makes and models. Some readers are known to be more universally compatible than others.
• Research Compatible Readers for Miata NBs: Search online forums and Miata-specific communities for recommendations on OBD2 Bluetooth readers that are confirmed to work reliably with 1999-2005 Miatas. User experiences can be invaluable in identifying compatible devices.
• Consider a Different Type of Reader (If Bluetooth is the Issue): If Bluetooth connectivity itself seems to be a persistent issue, you could consider a Wi-Fi based OBD2 reader (instead of Bluetooth) or a dedicated handheld OBD2 scanner.

Conclusion

Connecting a BAFX OBD2 Bluetooth adapter to a 1999 Miata should be straightforward, but compatibility issues can sometimes arise. By following these troubleshooting instructions, verifying your setup, and exploring alternative apps or readers, you should be able to diagnose and resolve the “No Response from Vehicle ECU” error. Remember to double-check OBD2 protocol settings in your app and consider trying different OBD2 apps for compatibility. If all else fails, researching Miata-specific OBD2 reader recommendations or considering a different adapter brand might be necessary to get your OBD2 diagnostics working smoothly.