OBDII dongle disconnects with engine running

[CheapJeep]

I recently bought an ELM327 bluetooth dongle and, while it works fine when the engine is not running, it continually disconnects when the engine is running. I've seen a few (not many) posts on the net where people have experienced similar issues, but have not seen an answers.

Anyone know if its likely to be my vehicle or the dongle? I'm guessing the dongle given its not high quality, but would like to be sure. I've tried a few different software apps and have pretty much ruled out the software as a problem.

Anyone in Brisbane have any codes they want checked/cleared for free?

[r1chard]

My guess would be the cheapo ebay dongle or else some form of EMF disrupting the Bluetooth signal.

You could test and possibly eliminate the EMF interference issue by putting another, known to be working, BT device such as a hands-free headset down near where ODBII dongle connects, and see if starting the engine causes similar problems with the different device.

If it's not the bluetooth layer, you may find the device does not connect reliably at the high speed perform communications speed. This 'speed' setting relates to the emulated serial comms port and probably the clock speed of the ODBII device, not the BT connection version (speed). Mine only really works at the 'slow' communications speed, which makes displays a bit 'laggy'. The software I use falls back automatically with a warning, or can be configured to only use slow speed. I use Torque which is an android app.

[Steve F]

I have one that 'looks' exactly the same as that one and it works 100% of the time, I did have issues with it dorpping out when talking to windows b ut that was to an external USB bluetooth dongle. Now I'm using Android it nevers drop out (to my tablet or phone)

Cheers
Steve

[Ando_13]

I have has a cheap bluetooth ODBII dongle since 05 (used it with Windows Mobile for many years). And some days it would stay connected for hours, other days would drop its connection. Had a mate write a nix app, and he experienced the same thing.
I have now switched to a USB version, which never misses a beat with a Win7 Tablet.

[CheapJeep]

Thanks for the comments/suggestions.

The software I've tried, being various WinXP and Symbian (Nokia phone) based, doesn't set the baud rate autonatically, but I have tried it at speeds from 9600 up. Didn't seem to make any difference. I'll drag out a couple of BT devices to check against to try and rule out interference as the cause. Apart from that I may just get a USB version as it would not make a great deal of difference to me really.

Shall come back with the findings.

Thanks again.

[Sifter]

I run that on my TJ without issues.

I have a spare one you can borrow and see if it is the actual unit you have.

I am in Brisbane South Side as well

[CheapJeep]

Sifter I might take you up on that generous offer...will pm you later.

Tried a replacement unit this morning and had exactly the same issue as before, so I'm starting to think it could be the OBD socket. Shall do some more testing when I get a chance.