What does it mean when a rpm history scan doesn't add up, per attached image? i.e rpms in each range don't add up to total. (only photo I have from sellers mechanic)

Is this typical ? Problem with PCM? Glitch in the scan?

The engine in question is supposed to be a '06 496HO...but header across the top says 350 MAG MPI?

Thanks.

wrong ECM for a 496 and the 496 is a pcm 555 - 3 connector

the ecm 555 is a 2 connector. So how many connectors do you have there ?

AND THE MIE is for inboards not I/O s so who bought the wrong computer ?

the 350 is ECM 555. and should be 2 connectors

run times is an internal ECM / PCM issue. I fix 555 ecms / pcms

just to clarify, hours by rpm range should add up to total? If not, there is an internal error?

thx!

I see there no problem!
I think some time before someone delete the runntimes hours.Its easy to to with Rinda software or so!
Fulltime hours can not delete,but the time in every rpm size can be deletet!
Michael

I would say at 266,8 hours all running specs are deleted! this are the missing hours when you ad the rest.
Michael

correct RPM run times aka run history ONLY can be erased and by whomever - the clear run history was erased at some point in time --- thats what happened here -- if you look at your pic - lower right hand corner it even shows clear run history as that what has tooken place.

Adding thou for whomever if overall TOTAL time does NOT calculate then its an internal ecm issue. Overall TOTAL time calculating not correct can happen where it just stops and I have seen incorrect overall TOTAL hours as well. I do know Volvo and if I recall Merc had ecms with wrong overall total hours logged. They had SBs reporting high hours and did not match the rpm run times.

For the problems if your looking for a 496 PCM 555 -- first off --- its displaying for MIE inwhich only is for inboard engines not sterndrives and its reads 350 MAG engine. You reported wanting an PCM for a 496 is this correct ?? That is not for a 496 and who sent you this for a 496 ?

I would ask the seller how many connectors / J connections does the ecm have ? ALL Merc 496 is PCM 555 with 3 connectors / J - connections. All ecm 555 have 2 connectors / J - connections and are not for 496 apps ( Mercruiser )

All OEM stock marine apps are ecm/ pcm specific cals. Even from closed cooling to raw cooling the ecm calibration for 555 and others are different.

Thanks everyone...BUP very helpful as always.
I asked a long distance seller to send me a screen shot of the run time on his 496HO. He requested it from his mechanic, and this is what I received.

I am going to ask him for a a $10K discount, since his boat only has a 350 :-), not the 496HO he is advertising. J/K

The header across the top lists 350MAG because that's what the operator of the CDS picked. It still might be a 496
But I'm surprised that it would read a PCM555 when a ECM555 was selected. The times that I've picked the wrong engine I would get a "can't connect, check cables" message. But I don't remember picking a ECM engine when I was trying to scan a PCM. Might still work but suggest you be a little suspicious at this point.