Jeep Cherokee 1999, Electronic Service Manual

Page: 1230 / 1948

ASD AND FUEL PUMP RELAYS
Th e fo llo w in g d e s c rip tio n o f o p e ra tio n a n d
te s ts a p p ly o n ly to th e Au to m a tic S h u td o w n
(AS D ) a n d fu e l p u m p re la y s
. Th e t er m in a ls on t h e
bot t om of ea ch r ela y a r e n u m ber ed (F ig. 30) or (F ig.
31).
OPERATION
•
Ter m in a l n u m ber 30 is con n ect ed t o ba t t er y volt -
a ge. F or bot h t h e ASD a n d fu el pu m p r ela ys, t er m i-
n a l 30 is con n ect ed t o ba t t er y volt a ge a t a ll t im es.
•
Th e P CM gr ou n ds t h e coil side of t h e r ela y
t h r ou gh t er m in a l n u m ber 85.
•
Ter m in a l n u m ber 86 su pplies volt a ge t o t h e coil
side of t h e r ela y.
•
Wh en t h e P CM de-en er gizes t h e ASD a n d fu el
pu m p r ela ys, t er m in a l n u m ber 87A con n ect s t o t er m i-
n a l 30. Th is is t h e Off posit ion . In t h e off posit ion ,
volt a ge is n ot su pplied t o t h e r est of t h e cir cu it . Ter-
m in a l 87A is t h e cen t er t er m in a l on t h e r ela y.
Fig. 28 Power Steering Pressure Switch—2.5L
Engine
Fig. 29 Fuel Tank Connections at Front of Fuel Tank
Fig. 26 Vehicle Speed Sensor—2WD
Fig. 27 Vehicle Speed Sensor—4WD
X J FUEL SYSTEM 14 - 39
DI AGN OSI S AN D T EST I N G (Cont inue d)