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Unread 03-08-2006, 11:55 AM   #1
Nickb1907
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Can i put the positive cable to the negative?

Im trying to do a PCM flash and it requires "discharging the capacitors in the memory" by touching the positive battery cable to a ground. Will the negative terminal work for a ground? Or will it blow up and kill me

If anyone else has done the PCM flash does it show you in any way that the memory is reset?

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Unread 03-08-2006, 12:01 PM   #2
RAAB3485
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Quote:
Originally Posted by Nickb1907
Im trying to do a PCM flash and it requires "discharging the capacitors in the memory" by touching the positive battery cable to a ground. Will the negative terminal work for a ground? Or will it blow up and kill me

If anyone else has done the PCM flash does it show you in any way that the memory is reset?
Touching the postive to the negative battery terminal should do the same thing as touching it to the ground because if you follow the wires off the negative battery terminal they just run to the chassis.
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Unread 03-08-2006, 12:01 PM   #3
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Depends on how big the capacitor is, you'll get some sort of spark. But do what it says and find a ground, better safe than sorry.
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Unread 03-08-2006, 12:18 PM   #4
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still no definete answer.... is the motor mount bolt a good ground?
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Unread 03-08-2006, 12:20 PM   #5
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Anything that goes to the chassis is a good ground. You can touch the engine even. Frame, bolts going to the frame, negative battery terminal, axles, all are bolted to the frame.
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Unread 03-08-2006, 12:24 PM   #6
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I guess the important thing is to remember we're talking about doing these things disconnected from the battery.
Quote:
Originally Posted by Nickb1907
........by touching the positive battery cable to a ground. Will the negative terminal work for a ground.......
So, yes, you can disconnect the positive battery cable, and touch it to the disconnected negative battery cable.
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Unread 03-08-2006, 12:27 PM   #7
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Quote:
Originally Posted by TeamCNY
I guess the important thing is to remember we're talking about doing these things disconnected from the battery.
So, yes, you can disconnect the positive battery cable, and touch it to the disconnected negative battery cable.
ya i was talking about doing it to the connected negative cable, a voice in my head was saying no, so i thought i would check
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Unread 03-08-2006, 12:33 PM   #8
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That does'nt read right to me,

normally when deflashing eproms you disconnect the chips positive input wire and short the chips pin to negative.

Not the +supply cable as that will just cause a short.

With most engine managements systems if you disconnect the battery for 20 mins Plus the system resets to factory defaults and re-learns the engines best settings.
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Unread 03-08-2006, 12:47 PM   #9
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Think about this for a second. The frame and engine and body are only "grounded" when the negative battery cable is connected. Touching the disconnected positive battry cable to the frame is exactly the same as touching it to the still connected negative cable.

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Unread 03-08-2006, 01:04 PM   #10
CNY
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Quote:
Originally Posted by Nickb1907
ya i was talking about doing it to the connected negative cable, ......
Quote:
Originally Posted by Toombs
......Touching the disconnected positive battry cable to the frame is exactly the same as touching it to the still connected negative cable.
Yes, disconnecting the positive cable and touching it to the connected negative cable would be fine (and accomplish the same thing as touching the + cable to any ground point in the car.

My suggestion to have both cables disconnected was over-doing it.
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Unread 03-08-2006, 06:39 PM   #11
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Quote:
Originally Posted by TeamCNY
Yes, disconnecting the positive cable and touching it to the connected negative cable would be fine (and accomplish the same thing as touching the + cable to any ground point in the car.

My suggestion to have both cables disconnected was over-doing it.

i did it and my jeep blew up, J/k

The hole time i was ducking for cover though
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Unread 03-08-2006, 06:48 PM   #12
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Quote:
Originally Posted by Nickb1907
i did it and my jeep blew up, J/k

The hole time i was ducking for cover though
the JEEP wounldn't have blown up, you just would have been sprayed with sulfuric acid... probably boiling sulfuric acid, if that happened at least you could collect disability, there's always a bright side
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Unread 03-08-2006, 06:51 PM   #13
Nickb1907
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Quote:
Originally Posted by VisitorJim
the JEEP wounldn't have blown up, you just would have been sprayed with sulfuric acid... probably boiling sulfuric acid, if that happened at least you could collect disability, there's always a bright side
that would have been so worth it so that i can get a handicap spot with a scar on my face. I hate how people take advantage of that.
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