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12v got applied to microsquirt pin 8--did I damage it?

PostPosted: Wed Dec 20, 2017 2:40 pm
by dougs951s
A short happened in my central fuse box and 12v got shunted accidentally to pin 8 on my microsquirt v3. This is a transistor that switches to ground to activate the fuel pump relay when the fuel pump should be running. My question is, would that damage the unit, and if so how do I find out where that transistor is located on the board and locate a replacement component so that it can be repaired? Would it be likely to damage anything else? Is that pin floating when not activated (the ecu is still being setup and so was not properly activating the relay on key on) and so maybe I got lucky and didn't damage anything? Really concerned about my board. Thanks guys.

Re: 12v got applied to microsquirt pin 8--did I damage it?

PostPosted: Wed Dec 20, 2017 2:57 pm
by racingmini_mtl
It should be fine.

Jean

Re: 12v got applied to microsquirt pin 8--did I damage it?

PostPosted: Wed Dec 20, 2017 4:24 pm
by dougs951s
Thanks for the quick reply Jean. That's what I wanted to hear ;)

Out of curiosity, how did applying 12v to a transistor which normally operates off 5v from the processor not destroy it? Interested in learning moment here; I'm a mechanical engineer so sometimes the specifics of electronics are out of my field of expertise.

Re: 12v got applied to microsquirt pin 8--did I damage it?

PostPosted: Wed Dec 20, 2017 4:41 pm
by racingmini_mtl
Unless I misunderstood your initial message, you did not apply 12V on the 5V side of the transistor but on the Microsquirt input on pin 8 of the connector. This already deals with 12V from the fuel pump relay. And the specific part used on the Microsquirt can deal with 40V+ and has short circuit protection.

Jean

Re: 12v got applied to microsquirt pin 8--did I damage it?

PostPosted: Fri Dec 22, 2017 5:32 pm
by dougs951s
Correct, I applied 12v to the purple wire going into pin 8 on the AMPseal connector. This is the input side to the transistor as I understand it, and is pulled to ground via a 5v signal from the processor. I had not thought about it, but yeah you are right, it has 12v grounding through it at all times via the FP relay during normal operation. This is why I'm a mechanical engineer and not an electrical engineer :D

Cheers

Re: 12v got applied to microsquirt pin 8--did I damage it?

PostPosted: Sat Jan 06, 2018 2:26 pm
by golturbo18
Hi friend, where can I create the file to save via BDM the initialization of mc9s12c64 because mine burned and replaced and I do not agree to write anything on it, because it asks for an initialization file before loading firmware .s19. could help me I paid dearly on this original processor and burned it queia recover