Experiencing trouble connecting your BAFX OBD2 reader to your 1999 Miata, even when the Bafx Obd2 Light is illuminated? It’s a frustrating situation when your diagnostic tool seems to power up but fails to communicate with your vehicle’s computer. Many Miata owners, especially those with NA and NC models, have readily available information online, but NB Miata owners sometimes find themselves in a troubleshooting maze. Let’s explore why your BAFX OBD2 reader might not be connecting to your ’99 Miata and what steps you can take to resolve this.
One common observation is seeing the red power light on your BAFX Bluetooth OBD-II reader after plugging it into the OBD-II port, typically found near the fuse box on the driver’s side. You’ve likely paired your Android device successfully and attempted connection through apps like Torque or Car Gauge Lite, only to be met with the dreaded “No response from vehicle ECU” message. This issue persists whether the engine is running or not, and you might have even verified the reader’s functionality on another vehicle, like a ’98 Civic, confirming the reader itself isn’t faulty.
So, what could be the problem? Let’s delve into some potential causes and solutions:
Is a Special Protocol Needed for a ’99 Miata OBD2 Connection?
It’s unlikely you need to manually specify a protocol. OBD-II readers are designed to automatically detect the correct protocol for your vehicle. However, some older OBD-II systems or readers might have compatibility quirks. While “Auto” protocol selection should generally work, if you have the option within your app, you could experiment with manually selecting ISO 9141-2, which is commonly used in older vehicles and compliant with OBD-II standards for 1999 models. This is usually a setting within your OBD2 app’s connection or adapter settings.
Are You Using the Correct OBD2 Port Location on Your Miata?
The OBD2 port location on a 1999 Miata is indeed typically found near the fuse box, to the left of the driver’s left knee. Removing the fuse box cover should reveal the connector. It’s possible your mechanic accessed a slightly different angle in the footwell, but the primary OBD2 port location for diagnostics remains consistent. You are likely using the correct port. The location under the fuse box can seem inconvenient, especially if you’re considering using a ScanGauge or similar device while driving. Unfortunately, this is the standard OBD2 port location for the NB Miata. While it might not be ideal for permanent mounting of devices, it is the correct port for diagnostic purposes and reader connection.
Alt text: The OBD2 port location in a 1999 Mazda Miata NB is shown located above the fuse box, to the left of the driver’s side footwell. This image highlights where to plug in a BAFX OBD2 reader for diagnostics.
NB Miata OBD2 Reader Compatibility: Is Your Car Picky?
While NBs aren’t necessarily “super picky,” compatibility issues can arise with certain OBD2 readers. The BAFX reader is generally well-regarded and not considered a “rock bottom cheapest” option, so it should work. However, variations in manufacturing, firmware, or even slight voltage differences can sometimes lead to incompatibility with specific car models. It’s not out of the realm of possibility that your ’99 Miata and this particular BAFX reader are simply not playing well together.
Troubleshooting Steps for “No Response from Vehicle ECU” with BAFX OBD2 Light On
Here’s a refined approach to troubleshooting:
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Verify BAFX OBD2 Light and Power: You’ve already confirmed the red light is on, indicating the reader is receiving power. This is a good first step.
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Double-Check OBD2 Port Connection: Ensure the BAFX reader is firmly and correctly plugged into the OBD2 port. Sometimes a slightly loose connection can prevent communication even if power is supplied.
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Try Different OBD2 Apps: While you’ve tested Torque and Car Gauge Lite, consider trying other OBD2 apps. Some apps might have slightly different communication protocols or initialization sequences that could work with your specific setup. Apps like OBD Fusion or DashCommand are popular alternatives.
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Restart Devices: A simple restart of both your Android device and, if possible, disconnecting and reconnecting the BAFX reader from the OBD2 port might resolve temporary glitches.
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Test on Another OBD2 Compliant Vehicle (Again): You’ve already tested on a ’98 Civic. If possible, try the BAFX reader on another OBD2 compliant vehicle from a similar era (late 90s/early 2000s) to further rule out a reader malfunction.
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Consider Reader Firmware (Less Likely but Possible): BAFX readers, like many electronic devices, might have firmware. Check if there’s a way to update the firmware of your BAFX reader. This is less common for basic OBD2 readers, but worth a quick check on the BAFX website or documentation if available.
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Miata ECU Issue (Less Likely Initially): While less likely to be the initial cause, a problem with your Miata’s ECU communication port is a possibility if all else fails. However, rule out reader and connection issues first.
Conclusion: Troubleshooting Your BAFX OBD2 Connection
The “BAFX OBD2 light is on but no connection” issue with your ’99 Miata can stem from several factors, ranging from simple connection problems to potential reader incompatibility. By systematically checking the OBD2 port, experimenting with different apps, and considering the possibility of reader-vehicle quirks, you can narrow down the cause. If, after thorough troubleshooting, you still face the “No response from vehicle ECU” message, it might be worth exploring a different brand or model of OBD2 reader to ensure compatibility with your NB Miata. If the issue persists across multiple readers, consulting a mechanic to check your Miata’s OBD2 port and ECU communication is the next logical step.
