Knock sensor and updating to newer O.S.

[Blacky]

Where paul has circled the knock-old sensor is the one i am talking about. If you open a 99 O.S. you will notice there is not only a #1 but also a #2. When you upgrade to 01 or 02 O.S. the #2 dissappears. I believe the knock sensors when upgrading from a 99 to a 01 or 02 still function off of the knock-old. So if im not able to adjust the #2 table and the computer is seeing this table at 0 it is unable to detect knock. I believe that is where i am getting my pinging from. When I Flash my pcm back to 99 pinging goes away. I adjust the #2 table to all zeros and I get the same knock as if i was on the 01 o.s. So my theory for us upgrading to 01 or 02 O.S. we need that secondary table on Knock-old

Maybe i'm wrong

It's a good theory, we might have to have a dig around and see if we can find the #2 tables...

Paul

[hpcubed]

Dig deep brother. My 402 is going in and the turbos are sitting in my bedroom. Need those sensors working proper

[Blacky]

Thanks for the reminder - something to do tonight
Paul

[Blacky]

Ok, I took another look. I am not 100% sure yet, but it appears the #1 and #2 may not be directly related to the 1 and 2 knock sensors as the EFILive descriptions imply. Instead it appears they may be invoked one after the other. Sort of like a double-pass filter. In later models, it appears the second pass was dropped. It seems to me like both knock sensors' voltages are filtered through the same table(s). Twice in early PCMs and just once in later PCMs.

It is difficult to be absolutely certain because the data from those tables is sent to an external chip to configure it to handle the filtering. I can't "see inside" that chip to see exactly what it is doing with the data. :(

Another possible option is that the knock filter chip has multiple modes of operation and early PCMs used a mode that required two sets of filter tables whicle later PCMs used a mode that only required one set of filter tables.

Sorry to be so vague, but whatever happens inside the knock chip is purely speculation at this point.

Regards
Paul

[87gmc]

Could we update to 01 knock sensors maybe?

[hpcubed]

Well sounds like a little more time is needed for Paul to resolve this but I think he has it in sight. Paul, I follow what you are saying. So how does the situation relate to EFIlive? If the hardware is different for the older PCM's then it seems that the software will need to convert the 2001+ OS so that the OS formats the data for the old hardware (ie. custom OS) - possibly with an enumerated type - old hardware/new hardware selector.

[hpcubed]

Any closer on solving this issue?

[kokki]

Any news?

I have ECM #9381344 .. 1999 Camaro Z28, can I first go to the 2000's OS and from there to COS3?

[hpcubed]

Can we put a 2001 computer in a 99 car without any side effects?

[hpcubed]

What about a custom operating system for the 99 so that it does not revert to the backup VE table?