Should I use PVC or ABS pipes for a swimming pool control system?
PVC is a good choice, provided that it is properly installed and maintained.  A proper installation includes shielding the PVC from UV light, which is the primary means of premature aging.  UV light will eventually turn PVC into a brittle mess.

ABS on the other hand tends to not become brittle with sun exposure, but to deform and is generally softer.  As a result, buried ABS pipe seems to be at a higher risk of crimping, impeding water flow.

In either case, you should paint your exposed pipe, which probably wasn't done, and is the primary reason you are looking to repair it.  Personally, I'd go with painted PVC, because after it is protected from UV light, it is less flexible (less pipe collapse) has a wider variety of fittings, and generally has a wider range of temperature distributions.  I'm also more familiar with PVC, which might cloud my judgement.  I'd love to hear from someone intimately familiar with ABS.

Both types of plastic are generally considered for low pressure applications, if you are having consistent freezing problems, neither pipe is meant to withstand routine freezing of water in-pipe.

PVC UVR is UV light resistant PVC.  Buy it and paint it if you want a very long lasting PVC solution.  Basically, you will have to worry about the (in my experience) natural enemies of PVC pipe before worrying about aging, that is careless yard crews, people vigorously digging, etc.