Upvote:2
No. According to the MTS page on Compass Cash, the prepaid credit program for Compass Cards:
Each time you tap on Trolley validators, or on the bus fare box for a one-way ticket, the value of that one-way fare will be deducted from your Compass Cash balance. You can deduct multiple one ways during the day or load a Day Pass. [...] Once a Day Pass is loaded, one way fares will no longer be deducted for the remainder of the operational day (for modes that accept the $5.00 day pass).
In other words, there is no automatic fare capping for Day Passes; you must explicitly load a Day Pass when boarding your first bus or at the ticket machine at your first station for rail services to avail the fare cap.