It’s a common frustration for car enthusiasts and DIY mechanics: you purchase an OBD2 reader, excited to delve into your car’s diagnostics, only to be met with a “No response from vehicle ECU” message. This is precisely the issue faced by a 1999 Miata owner using a BAFX Bluetooth OBD-II reader, as detailed in their forum post. Let’s break down the potential causes and solutions to get your Bafx Obd2 reader working with your NB Miata.
Understanding OBD2 Connection Problems with Your Miata
The user in question is experiencing difficulty connecting their BAFX OBD2 reader to their 1999 Mazda Miata (NB). They’ve correctly identified the OBD2 port location under the fuse box cover to the left of the driver’s knee and confirmed the reader works on another vehicle (a 1998 Honda Civic). This points to a potential issue specific to the Miata or the reader’s compatibility with this particular model. Let’s address the user’s questions and explore troubleshooting steps.
1. Protocol Compatibility and Manual Selection
The first question revolves around whether a specific protocol needs to be manually selected for a 1999 Miata. OBD2 protocols are standardized, but early OBD2 implementations, particularly in the late 90s, could sometimes be less universally compatible than later systems. While the BAFX OBD2 reader should ideally auto-detect the correct protocol, there’s a possibility that manual selection might be necessary.
Possible Solutions:
- Check App Settings for Protocol Selection: Torque (and other OBD2 apps) often have settings that allow you to manually specify the OBD2 protocol. Look for options like ISO 9141-2, which is commonly used in older Mazda vehicles. Experiment with manually selecting different protocols within your Torque app settings to see if a connection can be established.
- Consult BAFX OBD2 Reader Documentation: Review the documentation that came with your BAFX reader. It might provide specific instructions or compatibility notes for older vehicles or troubleshooting tips for connection issues.
- Verify Miata OBD2 Protocol: While generally OBD2 compliant, confirming the specific protocol used in a 1999 Miata can be helpful. Online Miata forums or repair manuals might provide this information.
2. OBD2 Port Location: Are You Plugging into the Right Place?
The user mentions their mechanic seemed to access the OBD2 port lower in the footwell, raising the question of whether they are using the correct port. While the primary OBD2 port in a 1999 Miata NB is indeed located under the fuse box cover on the driver’s side, it’s worth double-checking for any alternative locations or hidden ports.
Verification Steps:
- Primary OBD2 Port Location Confirmation: The location described by the user (under the fuse box cover, left of the driver’s left knee) is the standard OBD2 port location for the NB Miata. It’s unlikely there’s another functional OBD2 port elsewhere.
- Visual Inspection: Double-check the area under the fuse box cover. Ensure you are plugging into the 16-pin diagnostic connector and not another connector by mistake. Refer to online images or diagrams of the NB Miata OBD2 port location to confirm you are using the correct one.
- Footwell Exploration (with Caution): While less likely, a quick visual check lower in the footwell area for any other diagnostic connectors wouldn’t hurt. However, be cautious not to tamper with any wiring or components you are unsure of. It’s highly improbable that a second, functional OBD2 port exists in a standard 1999 Miata.
3. BAFX OBD2 Reader Compatibility with NB Miatas: Picky ECUs?
The user’s third question hits on a crucial point: are NBs (NB Miatas) particularly sensitive or picky about OBD2 readers? It’s possible that some older ECUs or OBD2 systems exhibit compatibility issues with certain aftermarket OBD2 readers. While BAFX readers are generally well-regarded, incompatibility isn’t impossible.
Exploring Compatibility Issues and Alternatives:
- Miata-Specific OBD2 Reader Recommendations: Search online Miata forums and communities for recommendations on OBD2 readers that are known to work reliably with NB Miatas. Miata owners often share their experiences and suggest specific brands and models that have proven compatibility.
- BAFX OBD2 Reader Reviews and Miata Compatibility: Look for reviews of the BAFX OBD2 reader, specifically mentioning compatibility with Mazda Miatas or similar vehicles from the late 90s/early 2000s. Customer reviews on Amazon or automotive forums can provide valuable insights.
- Consider a Different OBD2 Reader Brand/Model: If troubleshooting steps fail and online research suggests potential compatibility issues between BAFX readers and NB Miatas, it might be necessary to try a different OBD2 reader brand or model. Brands like Veepeak, OBDLink, or ScanTool are often recommended for their broader compatibility.
- Return and Exchange Options: If you suspect the BAFX reader is incompatible, consider returning it to Amazon and exploring alternative OBD2 readers with better-documented compatibility for your vehicle.
Conclusion: Getting Your OBD2 Reader Connected
Troubleshooting OBD2 reader connection problems can be methodical. For the 1999 Miata owner with the BAFX OBD2 reader, the key steps are:
- Verify OBD2 Port Location: Ensure you are using the correct port under the fuse box cover.
- Manual Protocol Selection: Experiment with manually selecting different OBD2 protocols in your Torque app.
- Research Compatibility: Investigate online Miata communities and reviews for BAFX OBD2 reader compatibility with NB Miatas and recommendations for alternative readers.
By systematically addressing these points, you should be able to diagnose whether the issue lies in protocol settings, port location (though unlikely), or reader compatibility. If the BAFX reader proves incompatible, switching to a recommended OBD2 reader for NB Miatas is the most likely path to successfully accessing your car’s diagnostic data and enjoying the benefits of OBD2 connectivity.
