Re: IF PPR requested but passport not in hand,Help?
The most important thing is not to do nothing. If you fail to respond, CIC can interpret that as abandoning your application.
If you do not think you will receive your renewed passport in time to satisfy the request, then you should contact your visa office with a letter explaining the delay, giving a reason (the renewal -- I presume it would have expired soon otherwise?) and an approximate timeframe on when you do expect to submit your passport.