I'm not requesting any data. I see this same message when I reset the oil life with my Tech2 clone as well. My ASSumption is that when the PCM has a new value for oil life it will send this message with the updated value.
I don't see any requests with 4A 60 in any of my logs.
Ok, now I know how you are reading the data. That helps.
As far as I know your assumption is correct. I cannot say that your ECM does this but it seems logical. I know my 2002 P10 PCM does this updating of the value. And my 2005 Yukon also does it.
Both vehicles clusters occasionally request the data as well. Here is a snippet from my Yukon where the PCM broadcasts the value, then shortly afterwards the cluster requests the same and the PCM again broadcasts the value.
I have hundreds of logfiles for my two vehicles spanning several years so it is possible for me to catch things that aren't a normal occurrence. But this request from a cluster looks to happen fairly often.
I don't think I have ever reset oil life using a Tech 2. Both my vehicles have the DIC and I use the steering wheel buttons to reset. I would expect the Tech 2 to use a service $AE message to perform such a reset.
That said I just sent a load command to a benchtop test PCM I have here in the house and the PCM did as I instructed. I spoofed a message from the BCM telling the PCM to load the value $FF into the oil life parameter.
I'll need to do some tests to see if it remains there when in the key off state and then later if the battery power is disconnected.
I assume there is just one always on battery power to your PCM?