Just had my 4.6 HSE regassed. Just before it was due in, the testbook symbol appeared for the first time ever. It reset and disappeared OK upon stopping and restarting the car.

Now, it's been regassed. Garage said there were no leaks at all and nothing to indicate a problem having been logged. However, the book icon keeps appearing after a few miles' driving.

It's hard to tell how efficient the air con is now, as the weather hasn't been so warm, but we did find it dishing out warm air on "Lo" once.

Any clues what we should be looking for?

i had a common problem .. after five minutes ( roughly ) of starting the engine , the book symbol appears ... the fault is within the board behind the heavac lcd ... so it coast me too much .. but as you say we can't ongo without the air co .
so good luck my mate ..
charbel.

Interesting. I'll have them check it out at MoT I guess. If you don't mind my asking, roughly how much did it cost?

I haven't really established a pattern with this, but the cold air does seem to flow more readily when the book symbol is on. Does it just take a while to get really cold anyway? And how cold should Ranger air con actually feel?