This is not something that happens automatically. You can’t lose it by living outside Canada, unless you live longer than the residency requirement

However, losing your permanent resident status must pass through an official process- an adjudicator or visa officer has to examine the situation and proves that you no longer meet the eligibility residency requirement when you apply for a temporary resident travel document or permanent resident travel document. You might lose your permanent resident status through any of the ways described below:

• If you are unable to live in Canada for 2 years out of a 5-year period
• If you are told to leave Canada or you committed a serious crime or
• You become a citizen of Canada

You won’t lose your permanent resident status if your Permanent resident card expires or if you voluntarily renounce your permanent resident status- there may come a time in your life in which you no longer want to be a permanent resident of Canada. If such happens, you can decide to give up your permanent resident status and that’s it.

For instance if you:

• are aware that you haven’t met your residency obligations by being outside the boundaries of Canada for a long period of time like more than 2 years in a 5-year period
• would like to come to Canada and
• wouldn’t like the visa officers to scrutinize your permanent resident status

Or

• Wouldn’t like to have any delay at the port of entry

If this is the situation, you won’t be able to visit Canada until your permanent resident status is amicably resolved by either voluntarily renouncing (giving up) your permanent resident status or receiving a PR travel document.