Hi all.. I don't on't usually write posts but I thought this may help..
I Had fault codes 4a79 and 4a74.. Which indicator a Problem with glow plug module or glow plugs themselves.. I change all the above and codes still not clearing so I look into any other codes that may be stored on the car.. I had a fault code that pointed towards the aux water pump which works the rest function on you ac unit.. I unplugged the pump.. Gave it a wiggle as I put it back in.. Cleared that code and then I was able to clear the above codes which I know has cause many people problems.. Hope this is the case for others on here and how this helps 🤞🤞