Strange Scanmaster Numbers

[Vince13]

I have had a Scanmaster on the car for 4 years and familiar the numbers however I went for a cruise tonight and just cruising along I am getting knock retard fluctuating between .1 and 0 ( point one not one degree)
The engine runs and sounds the same, I don't here any ticking or valve train noise. When I cycle through the rest of the numbers I noticed the Int reading cycling between 128 and 00 at idle.

I have checked the connections and will pull the ecm and reseat the power logger board on the weekend.

Anyone encounter this before?

Thanks

 

[TurboBob]

the ecm uses the same chip to run the low speed fan and send the data. I have seen the fan signal crosstalk into the data.

see if there is a correlation between the fan running and the funny data. The times I have seen it stepping on the brakes makes it worse.

you can try unplugging the low speed fan relay (the middle relay on the driver side) as a test also.

Bob

 

[Vince13]

Ok I will give that a try, I also noticed driving into work today that the BLM would flicker between 131 and 00 as well as the MPH stopped at a light would toggle between 00 and 01.

It is also showing malfunction codes 24, 42, and 55

Thank you for your help.

 

[bpman1234]

After you do the resetting if it still happens check your grounds connections

 

[Vince13]

Just to update the post shortly after my alternator went. I rebuilt it and that lasted 2 weeks so I went to the Caprice 140 amp unit and it stopped giving me the strange data. Unfortunatley that one lasted 3 weeks so I need to find the spare time to warranty that one.
I think it may be something in that area of the harness I may be disturbing. Time will tell.