Hello,
I recently spent some time uncovering the history of one of my ancestors.
There are two vital steps to follow:
1. Request the personnel file from Library and Archives Canada
library-archives.canada.ca
Note this may take several months.
This will tell you where your grandfather was posted at what dates.
2. Search for the war diary of 4 Fd Amb (and other units to which your grandfather was attached as will be described in the personnel file).
Once you know the dates your grandfather was with that unit, you can read where they were located, key activities, etc.
library-archives.canada.ca
The quantity and quality of information made available by the Government of Canada is astonishing for its completeness.
Good luck and let us know what you learn.