Audi Q7 361 - Page 65

Amb i ent temper at ur e sen s or
F o r eva l uation of the a mbien t temper a t ur e, tw o sensors ar e u s ed in th e delux e a u toma tic a i r conditio ner a nd
the f o ur - z one deluxe a u t o ma tic a i r conditioner .
Amb i ent tem p er atur e s e nsor G17
T h e mea s ur ed value fr om th e amb i ent temperatu r e senso r G 17 i s evaluated by the contr o l unit J285 in the
da s h pane l inser t and tr ans m i tted t o the Cli m atr o ni c contr o l unit J255 via the convenience CAN data bu s.
Fr es h ai r i n take d u ct te mp era t ur e sensor G89
T h is is evaluated by the Cli m atr o ni c contr o l unit J255.
T h e ambient temper a t ur e sen s or G17 is installed in the fr ont end section.
T h e fr esh air inta ke duc t temperatur e sender G89 is loc a ted in the intake h o using o f the air conditioner u n it.
T h e Climatro nic contr o l unit J255 always evaluates the lower of the tw o ambient temp e r atur e valu es. In the
even t of f a ilur e of one of the sensors, the other a m bi ent temp e r atur e valu e is ado p ted. Sho u ld both amb i ent
temper a t ur e se nsors be de f e c t ive, a substitu te valu e of 10 °C is permanently a ssumed.
Re frigeran t tem p er atur e sender G454
T h e sende r is installed in the high-pr e ssur e line,
near the compr e sso r . Its p u rpo s e is t o determine the
r e friger ant temperatur e and t o tr ans m it it t o the
Climatro ni c contr o l unit J255.
T ogether with the cur r e nt r e fr igerant pr essur e ,
a
mb i en t temper a t ur e a nd coolant temperatur e
values, th e Climatro ni c contr o l unit J255 is able t o
diagnose gr adual c o olant loss. F o r this purpose ,
fur t her conditions, suc h a s en gine idl i ng speed
mu st be av ailable.
A REFR I G ERANT LOSS f a u l t e n ter e d in the f a ult
memory r e mains static, not spor adic. T h e f a ul t
memory en try is s t or ed until the value detected b y
the sender G 454 r e tu rns t o within th e r e q u i r ed
r a nge. T h is c a n be a c hie v ed, f o r instanc e , b y se al in g
the r e friger ant circuit and r e f i lling the r e fr iger ant.
I n stalla tion of the sender depends on the engine
version. In vehicl es w i th V6 MPI and V6 FSI engines ,
the sender is not used.
361 _ 114
No t e
T h e r e friger ant temper a t ur e sender
G 454 connectio n is not eq uipp e d with
a
v a lve. T h e sender must ther ef or e only
b e r e mo ved wh en the r e fr ige r ant circuit
is empty .
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