reset with a wrench?

I had an installer show me a trick at another store and found it interesting and kinda worrisum as well. He said that if you trip  a check engine light, pull the negative off the battery and hold a wrench to the negative lead and rub the other end of the wrench on the positive post of the battery. He showed me this on a cav and it worked fine but I am still kinda worried about doing this with some of the new vehicles out there. I understand that its discharging any residuals in the vehicle but on some of these new vehicles with can-bus and what not is this gonna mess up their on board systems?double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

Yeah, all he was doing was discharging any caps. The same thing is done by leaving it unhooked for 15 minutes, and this is much safer.Certified Security Specialist

Always check info with a digital multimeter.

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