CKP and CMP sync readings using Auto Enginuity

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Jan 3, 2012 | 04:41 PM

fixxxer-upper

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From: Winder, Georgia

CKP and CMP sync readings using Auto Enginuity

I had the truck up to temp and was monitoring the engine with Auto Enginuity. I noticed that the value for CKP and CMP sync was constantly changing from 1 to 0. The value for FICM sync held at 1 and never changed. When I connected the SGII to compare, both of my X-Gauges for FICM SYNC and CKP/CMP sync stayed at 1.

Has anyone else had the same results with AE vs. SGII? Or is my camshaft sensor failing, and the SGII X-Gauge is not scanning/reporting the value constantly? If the Auto Enginuity values are correct, would the CKP CMP sync/no sync affect the cylinder power balance readings?

Thanks

Jan 3, 2012 | 05:15 PM

npccpartsman

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From: Stuttgart, Ar

My AE and SGII do exactly the same thing. I think in some way it's related to the update speed of the programming for both.

Jan 3, 2012 | 05:21 PM

fixxxer-upper

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FTE Fan

Joined: Jun 2007

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From: Winder, Georgia

Quote:

Originally Posted by npccpartsman

My AE and SGII do exactly the same thing. I think in some way it's related to the update speed of the programming for both.

Thanks for the info. I just wanted confirmation from somebody that has used the software and had the same readings.

Jan 3, 2012 | 05:39 PM

Jimbob8

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Joined: Nov 2011

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From: SE Louisiana

Glad ta hear it's a software thing, I see it on AE, was thinking gear backlash or sensors.

Jan 3, 2012 | 07:19 PM

dchamberlain

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From: Scio, OR

I seem to recall reading somewhere that sync was only really necessary when starting the engine. After that, the PCM kept track internally of which crank revolution matched which 1/2 of the cam revolution and that only the crank sensor was used for timing.

I'm not sure if this is true or not, but the crank sensor produces 58 pulses and 2 spaces per revolution for pretty precise timing. The cam sensor produces a single pulse per cam revolution and can't really provide any more information than which stroke each particular cylinder is on.

I'm not really sure if that explains why AE shows the PCM going out of sync periodically, unless it actually is and doesn't matter.