I bought a OBD2 Bluetooth scanner online. However, when I connect it to the OBD2 port in the car, the app while connecting to the OBD2 scanner gives an error message that it cannot connect to the cars ECU. I do not have the engine light on but would like to check whether the scanner works or the ECU is not bad.

Please find the attached image of the protocols the device supports.

Could anyone let me know where the issue lies? I thought the ECU fuse may have gone.

Thanks & Best Regards


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    what is year make and model? If your car is running then its more likely the obd2 scanner you purchased does not have the correct protocol to read your ecu. – narkeleptk Feb 28 '20 at 23:54
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    Hi mate, thanks for the reply. The car is a 2002 Mitsubishi Lancer 2.0l VRX model car. Thanks – Michael Schroter Feb 29 '20 at 1:46
  • I checked it with another car (Toyota Echo 2003) same issue. Would you be able to let me know what the issue is and how to rectify it. Thanks & Best Regards – Michael Schroter Feb 29 '20 at 3:35
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    you tried different ELM apps to connect like "Torque" or similar – Ganapathy C Jul 17 '20 at 16:39
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    I have the same issue on my mitsubishi pajero 96 model and it works on Ford and volks wagen touareg may be the coms protocol on mitsubishi is the problem. – Joseph Oct 3 '20 at 6:39

I would first wiggle or apply slight pressure to the connector while you are trying to connect. It could possibly just be from loose connection with the obd port. This is common on older vehicles

Your lancer's year & model should be doing diagnostics through K-line (obd2 pin 7) So probably ISO 14230 or ISO 9141 protocol. Check to see if your device supports these, its possible it only supports CAN style diagnostics found on most 2006+ models.

If your device does support KLINE protocols but fails then you should consider using a digital multi meter and doing a continuity check on the diagnostics wire between your obd2 and pcm to see if you have a broken wire.

There is no fuse that would block diagnostics only power to the device or your pcm. If this was the case then your engine would not run and/or your device would not power on.


  • Hi I have uploaded the protocols that the item uses. Thanks Michael – Michael Schroter Mar 2 '20 at 4:50
  • I don't know the device sorry. Maybe you just got a faulty one. – narkeleptk Mar 2 '20 at 13:13
  • Someone at the local autoparts store told me that cheap phones could be also a cause for this. Would you be able to let me know if this could be also a reason? Thanks Michael – Michael Schroter Mar 3 '20 at 23:51
  • If its connecting via Bluetooth and the app is install-able on your phone then I do not see the phone being the issue. However like I said, I know nothing of the device you added to the question so its just assumptions on my part. – narkeleptk Mar 4 '20 at 1:03
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    Hi, yes it connects via Bluetooth to my phone. The app is also installable. Like you said it looks like a device issue. Thanks – Michael Schroter Mar 4 '20 at 5:23

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