Hi, just like to share, and to confirm, that the suggestion to select the Network Mode as "GSM only" worked for me.
I have been using a Huawei Y511-U10 (Jelly Bean 4.2.2) for the last 2 years and never encountered this problem until about a week ago when it just come on from nowhere and refused to go away ever since. The GPS turns on everytime when there is an incoming call or when I dial out to make a call. Manually turning the location access off just didn't work regardless of how many times I try. I also checked the Running apps at the time when GPS is automatically turned on but found nothing that links to any request for Location Service by the apps.
Intuitively, I only suspected that it somehow had to do with the dialer but found no evidence that firmly points to it. Interestingly, no new apps were installed recently - before, during or after - the problem was first observed. My phone had always been on "GSM/WCDMA (auto mode)" from Day 1. So, it baffles me a lot why it happens only now after 2 years.
I (still) don't know as to why this problem came about but I'm glad that it managed to address the issue for now and relieves me of the annoyance and pain of having to turn off the GPS with each incoming and outgoing call. Hope this may bring some relief to all who are affected...