Experiencing trouble connecting your Bafx Bluetooth Obd2 Scanner to your 1999 Miata? You’re not alone. Many Miata owners, especially those with the NB model like your ’99, sometimes encounter connectivity issues with aftermarket OBD2 scanners. Let’s troubleshoot why your BAFX scanner might be giving you the dreaded “No response from vehicle ECU” error and explore potential solutions.
It sounds like you’ve already taken the initial steps: plugging in the scanner, seeing the red light, pairing your Android device, and trying apps like Torque and Car Gauge Lite. The fact that your BAFX scanner works on your ’98 Civic indicates the scanner itself is likely functional. This points towards a Miata-specific issue. Let’s dive into the common culprits.
Common Causes and Compatibility Checks
You asked some excellent questions in your original post, so let’s address them directly and expand on each point to help you diagnose the problem.
1. Protocol Compatibility and Manual Selection:
You’re right to question if a specific protocol needs to be selected. While OBD2 is a standard, the 1999 Miata (NB generation) can be a bit particular. OBD2 was mandated in the US starting in 1996, but early implementations sometimes had nuances.
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OBD-II Protocol Variations: The OBD-II standard encompasses several communication protocols. While “Auto” protocol detection usually works, some older vehicles prefer a manually selected protocol. Your 1999 Miata likely uses ISO 9141-2 or ISO 14230-4 (KWP2000).
- Action: Within your Torque or Car Gauge Lite app settings, see if you can manually specify the OBD-II protocol. Try selecting ISO 9141-2 or KWP2000 instead of “Auto.” This might force a successful connection.
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Scanner Compatibility: While BAFX scanners are generally well-regarded for their compatibility, it’s always worth double-checking if there are any known issues with specific car models, especially older ones.
- Action: Visit the BAFX website or Amazon page where you purchased it and look for user reviews specifically mentioning Miata or Mazda vehicles. See if other users have reported similar issues or successful connections.
Verifying the OBD2 Port Location
Your mechanic seeming to access the OBD2 port lower in the footwell is a crucial observation.
2. OBD2 Port Location on a 1999 Miata:
You mentioned finding a port under the fuse box cover near your left knee. While there might be connectors in that area, the standard OBD2 port location on a 1999 Miata (NB) is typically in the driver’s side footwell, closer to the center console and lower than the fuse box area. It’s often near the hood release lever.
Alt text: Location of the OBD2 port in the driver’s side footwell of a Mazda Miata NB, indicated by a red arrow, showing its position lower than the fuse box.
- Action: Double-check the footwell area, lower and closer to the center console. You might need to look carefully as it can be tucked away. Using a flashlight can be helpful. Ensure you are plugging the BAFX scanner into the correct 16-pin OBD2 port. The port you found under the fuse box might be for a different diagnostic system or accessory.
Scanner Pickiness and Alternatives
3. Miata OBD2 Scanner Sensitivity and Trying Alternatives:
NB Miatas aren’t necessarily “super picky,” but like many cars, variations in OBD2 implementations and scanner quality can lead to compatibility issues. Your BAFX scanner is generally a reputable choice, but sometimes, specific units or vehicle combinations just don’t play well together.
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Scanner Variations: Not all OBD2 scanners are created equal. Some have better protocol handling or are more robust in their communication. While BAFX is generally good, there’s always a chance of individual scanner quirks.
- Action: Before considering returning your BAFX scanner immediately, try the manual protocol selection and verify the OBD2 port location as mentioned above. These are often the simplest fixes.
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Alternative Scanners (If Troubleshooting Fails): If you’ve tried everything and still no connection, it might be worth considering another OBD2 scanner, although this should be a last resort. If you decide to explore alternatives, look for scanners that are explicitly listed as compatible with Mazda or Miata vehicles, especially those known to work well with older OBD2 implementations. Brands like OBLink MX+ or some Veepeak models are often recommended in Miata communities for reliable connections.
Final Steps and Recommendations
Before concluding that your BAFX scanner is incompatible or your Miata’s OBD2 system is faulty, re-verify these steps:
- Correct OBD2 Port: Confirm you are using the OBD2 port in the driver’s footwell, low and towards the center console.
- Manual Protocol Selection: In your app (Torque, Car Gauge Lite), manually select ISO 9141-2 or ISO 14230-4 (KWP2000) protocol.
- App Compatibility: Ensure your chosen app is fully compatible with generic OBD2 scanners and supports protocol selection.
- Scanner Functionality (Already Confirmed): You’ve confirmed the BAFX scanner works on your Civic, so the scanner itself is likely functional.
By systematically checking these points, you should be able to pinpoint why your BAFX Bluetooth OBD2 scanner is not connecting to your 1999 Miata. If all else fails, consider seeking advice from Miata-specific online forums or a trusted mechanic who specializes in Mazda vehicles. They might have encountered similar issues and offer further insights.
