So, there may already be something on this somewhere, so happy for this to get deleted, but I thought I'd relate something I found interesting in the hope it might help someone else.
My truck has never lost sync. Unlike some people's who seem to go through the issue regularly.
When I say never has ..... what I mean is hadn't until last night. Jump in, hit the key, nothing. Check it is in park, still nothing. Cycle the gears to check the XYZ, still nothing, then I noticed no CEL. Ah! loss of sync. cycle the key a few times, CEL back on, starts up and off I go.
I was pondering later, why, after two years of trouble free starting, would this have happened. What did I do different. So here it is for what it is worth.
I have an aux socket in the back. When I wired it in I took the feed directly off the under seat fuse box live feed. This feed, I assume, is where the BeCM gets is power from. So what did I do different? I plugged in a compressor driven fridge to the aux socket just before I went to start the truck.
Did the consequent lowering of voltage at this feed point interfere with the BeCM and its communication with the ECU?
Are the loss of sync issues come people have due to a poor connection between the under bonnet supply and the BeCM supply, resulting in a dip in voltage when you turn on the key?
No idea, but I thought I'd throw it out there.
Of course my experience might be totally unrelated at all, but .......