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I have read that those cheap OBD2 readers can kill your ECU if you leave them plugged in forever (Especially the crappy ones used by insurance companies to monitor your driving).

Archive: https://archive.today/4CpbV

From the post:

>It’s no real secret that modern-day cars are basically a collection of computers on wheels, which also means that we get all the joys of debugging complex computer systems and software with cars these days. Rather than a quick poke under the hood to rebuild a carburetor and adjust the engine timing by hand, you’ll be pulling out a scan tool to gain access to the computer and figure out why the darn thing won’t start after someone else used a scan tool on it, as happened to [DiagnoseDan].

I have read that those cheap OBD2 readers can kill your ECU if you leave them plugged in forever (Especially the crappy ones used by insurance companies to monitor your driving). Archive: https://archive.today/4CpbV From the post: >>It’s no real secret that modern-day cars are basically a collection of computers on wheels, which also means that we get all the joys of debugging complex computer systems and software with cars these days. Rather than a quick poke under the hood to rebuild a carburetor and adjust the engine timing by hand, you’ll be pulling out a scan tool to gain access to the computer and figure out why the darn thing won’t start after someone else used a scan tool on it, as happened to [DiagnoseDan].
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[–] • 2 pts

Depends on the "scan tool". Most of the cheap OBD2 code readers are incapable of writing to the ECM and often don't even have the "transmit" line wired up to be able to send data. More expensive scan tools with features that can make performance adjustments and such might get you in trouble if you change things without knowing what the fuck you or the tool are doing. Anything that replaces your ECM firmware is where you are likely to really fuck things up. Car guys with these sorts of tools are just asking for trouble. Don't let anyone use such a tool on your car.

[–] • 1 pt

The cheap one's I was talking about fried the ECM rather than write to it. They caused voltage problems that cooked the computer.

[–] • 1 pt

I don’t see how this could happen. The odbii provides 12v and the device sucks it. How can something that draws the voltage that’s provided fry anything?

Not doubting YOU, but doubt the reports. It’s like saying I installed headlight and it fried my ecu.

[–] • 1 pt

The cheap one's I was talking about fried the ECM rather than write to it. They caused voltage problems that cooked the computer.

You must have had a really fucked up scan tool. Most of the cheap ones seem to built around the ELM327 OBD2 chip and I've used various versions of them along with tablet apps like Torque to see codes and performance data. I've even used an ODB2 splitter cable to run an ELM327 scanner alongside an after market heads up display with no issues. The heads up display didn't have the TX pin wired up at all so it couldn't talk back to the ECU. Perhaps your device was drawing more current than your OBD2 port could supply and that cooked the ECU voltage regulator.

[–] • 1 pt

Oh, to clarify this was a combo article and video on the matter. I did not have it happen to me. I have used scanning tools (some with write ability) since I am a crazy person but I have never killed a ECU myself.