1996 ACURA RL KA9 Service Repair Manual

Description
Fan Contro l Uni t
The fa n contro l uni t make s calculation s base d o n signal s fro m th e radiato r fa n contro l sensor . I t the n control s th e opera -
tio n o f th e radiato r fan , condense r fa n an d A/ C system .
ON
OF F
172° F (78°C )
183°F (84°C )Whe
n engin e coolan t temperatur e is abov e 183° F (84°C) ,
th e fa n contro l uni t turn s Tr 1 ON , an d th e radiato r fa n
(Low ) an d condense r fa n run s (Low) .
ON
OF F
183° F (84°C )
When engin e coolan t temperatur e is abov e 194° F (90°C) ,
th e fa n contro l uni t turn s Tr 2 ON , an d th e radiato r fa n
(High ) runs , an d th e condense r fa n (High ) goe s on .
194° F (90°C )
ON
OF F
225° F (107°C )When engin e coolan t temperatur e is abov e 228° F (109°C) ,
the fa n contro l uni t turn s Tr 3 OFF , an d stop s th e A/ C com -
pressor .
228°F (109°C )
*1: CONDENSE R FA N RELA Y*2: RADIATO R FA N RELA Y*3: RADIATO R FA N MAI N RELA Y
RED/WH T
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A/C Pressure Switch

The A/C pressure switch consists of a High-Low pressure switch (A/C pressure switch A) and a Middle pressure switch

(A/C pressure switch B).

High-Low pressure switch

If the refrigerant pressure becomes too high (due to blockage), or too low (due to leakage), the A/C pressure switch

sends a signal to the fan control unit to prevent the compressor from operating.

ON

OFF

• Middle pressure switch

If the refrigerant pressure goes above or below 1,520 kPa (15.5 kgf/cm2, 220 psi), the A/C pressure switch sends a signal

to the fan control unit to change the speed of the condenser fan and radiator fan (High-Low).

290 kPa (3.0 kgf/cm2, 42 psi)

ON

OFF

1,230
kPa

(12.5 kgf/cm2,178 psi)
1,520
kPa

(15.5 kgf/cm2,220 psi)

MIDDLE

PRESSURE

SWITCH
HIGH-LOW

PRESSURE

SWITCHProCarManuals.com

Description
The evaporato r pressur e regulato r (EPR ) i s a pressur e contro l valve . Th e EP R is locate d behin d th e low-pressur e sid e o f th e
evaporator , an d keep s th e pressur e in th e evaporato r constant . Whe n th e evaporato r pressur e drop s belo w abou t 19 6 kP a
(2. 0 kgf/cm
2) [28. 4 psi ] th e pisto n close s t o kee p th e pressur e i n th e evaporato r abov e 19 6 kP a (2. 0 kgf/cm2) [28. 4 psi] .
Consequently , th e EP R keep s th e evaporato r temperatur e an d th e deliver y temperatur e constant .
Open
PISTO N
Close
177 20 2 kP a(1.8 0 2.0 6 kgf/cm2)[25. 6 29. 3 psi ]PRESSUR E
BELLOWSPISTON
Compresso r sid e Evaporato
r sid e
SPRIN G
Evaporato r Pressur e Regulato r (EPR )
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Troubleshooting
Symptom Char t
For electrica l malfunction s whic h ar e indicate d b y th e self-diagnosti c system , refe r t o self-diagnosi s functio n (se e nex t
page) .
NOTE :
Check th e engin e coolan t level , an d allo w th e engin e t o war m u p befor e troubleshooting .
An y abnormalit y mus t b e correcte d befor e continuin g th e test .
Becaus e o f th e precis e measurement s needed , us e a multimete r whe n testing .
Befor e performin g an y troubleshootin g procedure s check :
— Fuse s No . 3 7 (4 0 A) , No . 4 7 (2 0 A) , No . 5 0 (2 0 A) , No . 5 6 (7. 5 A ) i n th e under-hoo d fuse/rela y box , an d No . 3 (7. 5 A) , No .
5 (2 0 A ) i n th e under-das h fuse/rela y bo x
— Ground s No . G201 , G301 , G302 , G401 , G402 , G40 4
— Cleanlines s an d tightnes s o f al l connector s
Symptom
Recirculatio n contro l door s d o no t chang e betwee n FRES H an d RECIRCULATE .
Th e blowe r moto r doe s no t ru n immediatel y eve n thoug h th e engin e i s full y warme d
up . (NOTE : Th e temperatur e contro l dia l mus t b e se t betwee n 6 1 °F [18°C ] an d 89° F
[32°C]. )
No heate r an d A/ C in eithe r manua l o r AUT O modes .
Bot h fan s d o no t ru n fo r engin e coolin g (bu t the y bot h ru n wit h th e A/ C on) .
Both fan s alway s ru n a t hig h spee d fo r engin e cooling .
Both fan s alway s ru n a t hig h spee d wit h th e A/ C on .
Radiato r fa n doe s no t ru n a t hig h spee d (bu t condense r fa n run s a t hig h speed , an d
bot h fan s ru n a t lo w speed) .
Condense r fa n doe s no t ru n a t hig h spee d (bu t radiato r fa n run s a t hig h speed , an d
bot h fan s ru n a t lo w speed) .
Bot h fan s d o no t ru n a t lo w speed , an d radiato r fa n doe s no t ru n a t hig h spee d (bu t
condense r fa n run s a t hig h speed) .
Bot h fan s d o no t ru n a t low speed , an d condense r fa n doe s no t ru n a t hig h spee d
(bu t radiato r fa n run s a t hig h speed) .
Bot h fan s d o no t ru n a t lo w spee d (bu t bot h fan s ru n a t hig h speed) .
Bot h fan s d o no t ru n a t hig h spee d (bu t bot h fan s ru n a t lo w speed) .
Compresso r clutc h doe s no t engage .
Bot h fan s an d compresso r d o no t wor k a t all . Se
e pag e
22-3 4
22-3 6
22-3 7
22-3 8
22-39
22-4 0
22-41
22-42
22-4 3
22-4 4
22-47
22-48
22-4 9
22-53
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