LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

icm a ground?

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Old 04-26-2011, 09:35 PM
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Question icm a ground?

my 95 camaro z28 6-speed want start. i replaced plugs/wires and optispark. still no start. i got to looking at the icm.
is the back of the icm a ground to the head?
thanks Dustyn
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Old 04-26-2011, 09:44 PM
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Re: icm a ground?

Pin C on the ICM connector, black wire, is the ground.
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Old 04-26-2011, 10:00 PM
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Re: icm a ground?

so the surface on the back of the icm itself isnt importand?

thanks allot frank
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Old 04-26-2011, 10:10 PM
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Re: icm a ground?

Originally Posted by twistedbowtie
so the surface on the back of the icm itself isnt importand?

thanks allot frank
Yes, it is important in that it should have heat sink compound on it and be mounted to the heat sink.
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Old 04-26-2011, 10:15 PM
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Re: icm a ground?

thanks shoebox. but im realy lost on what you are explaining?

could that be what is keeping my car from fireing?
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Old 04-26-2011, 10:41 PM
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Re: icm a ground?

The ICM is mounted to a heat sink that is mounted to a plate that is mounted to the front of the cylinder head.

http://shbox.com/coil/coil.html

The ICM must remain cool to operate. Most auto parts stores can test it.

If you are getting no spark, you may want to do this test, too:
http://shbox.com/1/4th_gen_tech2.html#opti_test
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Old 04-26-2011, 10:41 PM
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Re: icm a ground?

Only if its causing the ICM to overheat. The "heat sink" is the metal base. The heat transfer compound goes between the module and the metal base, to help pull the heat out of the ICM. But it can still overheat even if installed correctly. That's why Shoebox has a page that explains how to space the ICM bracket off the head, to reduce heat soak.

Problems with the ICM, including shorts and grounded circuits will show up as trouble codes. Have you scanned it for codes?
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Old 04-27-2011, 12:42 PM
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Re: icm a ground?

no the car hast started since i replaced head gaskets so i didnt think it would throw any codes.

thanks allott guys
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Old 04-27-2011, 03:38 PM
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Re: icm a ground?

The PCM does diagnostics on some systems as soon as you turn the key to "start".
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Old 04-27-2011, 06:05 PM
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Re: icm a ground?

oh okay ill try and find someone with a scaner to scan the codes and see where im at there
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