Hevac book icon - any ideas?

Hi chaps,

Driving home last night in -2°C, heating on 28°C AUTO, and the book icon popped up.
Anyone any ideas as to a likely cause, or is it pop to diagnostics, and is it something that should be done ASAP?

Thanks!

Blend motor is the most likely. I never run it on Auto as it uses the blend motors more. Only way to be sure is diagnostics. No urgency if the cabin temperature and distribution is OK.

When it's -2 outside, turn the household heating up to 28. Chuck the missus out naked and see if there is any similar objection.

Suspect it was just the car being feminine. Expect a letter from its solicitors that includes the words "unreasonable behaviour".

G~

Datatek said:

Blend motor is the most likely. I never run it on Auto as it uses the blend motors more. Only way to be sure is diagnostics. No urgency if the cabin temperature and distribution is OK.

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Thanks Data

To my relief/annoyance that I'm clogging up the forum; I did a 2 hour round trip to Heathrow earlier and it didn't come on (0°C vs 25°C AUTO).. so might iy have just been having a moment?

Also, this is going to sound terrible... but, what's a blend motor? :$

blend motors are things that have blonde moments

As the heater is all push button something must physically move the air distribution flaps and change the amount of heat being allowed into the system. These things are electric motors known as blend motors. There is a feedback system on each so that the system knows that the motors are going where required. If they don't then the cheque book symbol pops up. The book will also appear if a flap jams and a motor cannot do it's job.

Ah I see, as opposed to traditional twisty knobs
So is it the case that something could have caused a little jam, which then clears and so the fault disappears? Would be lovely if that were the case

you might find that it goes away on its own after a couple of days. its in the handbook about them doing self diagnostics every 100 - 300 turns of the ign key.

but dont rule out the motors though.

the blower motors are the most likley cause of open book symbol. failure to change the pollen filters causes them to burn out. check them by removing pollen filters and looking inside , you should by able to see the fans spinning or not as the case may be

press all the buttons until it goes away - same theory on a B737!

aerofabrique said:

press all the buttons until it goes away - same theory on a B737!

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deffo not going in a plane with you!

sas1810 said:

deffo not going in a plane with you!

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Shame a p38 doesn't have circuit breakers you can just pull to make annoying things go away.

aerofabrique said:

Shame a p38 doesn't have circuit breakers you can just pull to make annoying things go away.

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now look here you, i gotta fly to south america again on monday, now shut up

its ok - its all legal to do that sort of thing if you're flying there

aerofabrique said:

its ok - its all legal to do that sort of thing if you're flying there

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bolliocks! :d:d:d:d:d:d

sas1810 said:

bolliocks! :d:d:d:d:d:d

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:d:d:d:d

Hi

I had the book on my HEVAC. Faultmate reported a fault of "left hand blower motor stop mode fault" a rather obtuse error message!

I swapped the blower motor relays and checked to see if the error swapped sides. It did! "RIGHT hand blower motor stop mode fault"

Installed a new relay and the book disappeared after a while. I also did a calibration of the blend motors BEFORE changing the relay so that may have been influential in removing the error, but the book did not disappear until the relay was changed.

I hope this helps.

Thanks
Definitely shows diagnostics is the way to go!
Since I have completed a lengthy journey with no book icon I believe it might have been a temporary issue, maybe something fell down and inhibited a motor briefly or something?
In the meantime replacing the front airbags is my priority!