The issue is No spark at the coil No Codes and a seemingly unconscious PCM

2000 CHEVROLET ASTRO
168,450 MILES
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LINDOPARK
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No Codes = MIL OFF and Security Lamp OFF also. Engine 4.3L The issue is No spark at the coil No Codes and a seemingly unconscious PCM
Apr 24, 2012 at 9:09 PM
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RASMATAZ
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So what's the problem here?
Apr 24, 2012 at 9:11 PM
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LINDOPARK
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Sorry, was not sure on how to reply before now. Posted one reply since. The issue is No spark at the coil No Codes and a seemingly unconscious PCM.
Apr 24, 2012 at 9:22 PM
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LINDOPARK
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How do I confirm that the trigger signal from the PCM is or is not occurring? I've checked that the CKP 5V signal is available to the PCM, yet my LED lamp will not flash when connected to the white wire of the ICM which is supposed to be the trigger signal from the PCM
Apr 24, 2012 at 9:35 PM
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RASMATAZ
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The voltage at the CPS should be fluctuating if its synchronizing
Apr 24, 2012 at 9:45 PM
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LINDOPARK
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It is fluctuating while engine being turned over using a wrench and 5V pulse is reaching PCM.
Apr 24, 2012 at 10:09 PM
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RASMATAZ
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If its fluctuating check the ICM and the computer
Apr 24, 2012 at 11:16 PM
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LINDOPARK
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Good voltage at ICM terminal A Pink wire. Good continuity Whte/blk wire
ICM terminal D to Ign Coil terminal C wire. Good continuity to earth at ICM terminal C Black wire. Dont have a scope and dont know what should be coming down ICM B terminal White wire from PCM. According to my diagram it should be an EST (Elec Spark Time Sig ?)I did a AC voltage test and saw 1.5VAC while cranking. Is that good, bad or wrong test?
Apr 25, 2012 at 12:29 AM