Your assumption is correct, there is no need to wait for pump to respond, I just don't like spamming can data until its needed. On my controller I actually check for the correct pump to respond, and have timeouts in case it stops talking.
Technically you don't have to have SPECIFIC timeframes to send the canbus data, just I tried matching to what OEM did. If I recall KAM can be sent every 250ms, while the VSS needs to be sent at most 100ms. Or other way around, I can't remember.
Recommend you guys use Mopar pumps, volvo is unreliable weak sauce stuff.
