Merge two lists of dicts of different lengths using a single key in Python

I want to merge two lists of dictionaries on a single key, when the two lists are different lengths (using Python 3.6). For example, if we have a list of dicts called l1:

l1 = [{'pcd_sector': 'ABDC', 'coverage_2014': '100'},
       {'pcd_sector': 'DEFG', 'coverage_2014': '0'}]

and another list of dicts called l2:

l2 = [{'pcd_sector': 'ABDC', 'asset': '3G', 'asset_id': '2gs'},
      {'pcd_sector': 'ABDC', 'asset': '4G', 'asset_id': '7jd'},
      {'pcd_sector': 'DEFG', 'asset': '3G', 'asset_id': '3je'},
      {'pcd_sector': 'DEFG', 'asset': '4G', 'asset_id': '8js'},
      {'pcd_sector': 'CDEF', 'asset': '3G', 'asset_id': '4jd'}]

How would one merge them using pcd_sector to get this(?):

result = [{'pcd_sector': 'ABDC', 'asset': '3G', 'asset_id': '2gs', 'coverage_2014': '100'},
          {'pcd_sector': 'ABDC', 'asset': '4G', 'asset_id': '7jd', 'coverage_2014': '100'},
          {'pcd_sector': 'DEFG', 'asset': '3G', 'asset_id': '3je', 'coverage_2014': '0'},
          {'pcd_sector': 'DEFG', 'asset': '4G', 'asset_id': '8js', 'coverage_2014': '0'},
          {'pcd_sector': 'CDEF', 'asset': '3G', 'asset_id': '4jd'}]

What I have tried so far

I've used the following code to merge the two lists, but I end up with a short version unfortunately, not the desired complete data structure.

import pprint
grouped = {}
for d in l1 + l2:
    grouped.setdefault(d['pcd_sector'], {'asset':0, 'asset_id':0, 'coverage_2014':0}).update(d)
result = [d for d in grouped.values()]
pprint.pprint(result)

So when I run the code, I end up with this short output:

result = [{'pcd_sector': 'ABDC', 'asset': '3G', 'asset_id': '2gs', 'coverage_2014': '100'},
         {'pcd_sector': 'DEFG', 'asset': '4G', 'asset_id': '8js', 'coverage_2014': '0'},
         {'pcd_sector': 'CDEF', 'asset': '3G', 'asset_id': '4jd'}]