7/29/2019 EXJ_8R99 jeep xj service manual

1/4

POWER SEAT SYSTEMS

CONTENTS

page page

GENERAL INFORMATIONINTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . 1

DESCRIPTION AND OPERATIONCIRCUIT BREAKER . . . . . . . . . . . . . . . . . . . . . . 2POWER SEAT ADJUSTER AND MOTORS . . . . . 1POWER SEAT SWITCH . . . . . . . . . . . . . . . . . . . 1

DIAGNOSIS AND TESTING

CIRCUIT BREAKER . . . . . . . . . . . . . . . . . . . . . . 2

POWER SEAT ADJUSTER AND MOTORS . . . . . 2POWER SEAT SWITCH . . . . . . . . . . . . . . . . . . . 2

POWER SEAT SYSTEM . . . . . . . . . . . . . . . . . . . 2REMOVAL AND INSTALLATION

POWER SEAT ADJUSTER AND MOTORS . . . . . 3POWER SEAT SWITCH . . . . . . . . . . . . . . . . . . . 2

GENERAL INFORMATION

INTRODUCTIONA s ix -w a y d r iv er s id e p ow e r s ea t i s a n a v a i l a bl e

f a c t or y -i n s t a l l ed op t i on f or L e ft -H a n d Dr i v e (L H D)

v er si on s of t h is m od el . Th e pow e r s ea t s ys t em

r ece iv es b a t t e ry f ee d t h r ou g h a f us e i n t h e P o w er

Distribution Center and a circuit breaker in the junc-

t i on bl ock a t a l l t i m es .

F ol low i n g a r e g en er a l d es cr i pt i on s of t h e m a jor

components in the power seat system. Refer to 8W-63

- P o w er S e a t i n G r o up 8W - Wi r in g D i a g r a m s f or

complete circuit descriptions and diagrams.

NOTE: This group covers both Left-Hand Drive

(LHD) and Right-Hand Drive (RHD) versions of thismodel. Whenever required and feasible, the RHDversions of affected vehicle components have beenconstructed as mirror-image of the LHD versions.While most of the illustrations used in this group

represent only the LHD version, the diagnostic andservice procedures outlined can generally beapplied to either version. Exceptions to this rulehave been clearly identified as LHD or RHD, if a

special illustration or procedure is required.

DESCRIPTION AND OPERATION

POWER SEAT SWITCH

Th e p ow e r s ea t ca n b e a d ju s t ed i n s ix d if fe re nt

w a y s u si ng t h e pow e r s ea t s w it ch . Th e s w it ch i s

located on the lower outboard side of t he seat cushion

frame. Refer to the owners manual for more informa-

t i o n o n p o w e r s e a t s w i t c h f u n c t i o n s a n d s e a t a d ju s t -

ing procedures.

Th e i n d i v id u a l s w i t ch e s i n t h e p ow e r s ea t s w i t ch

module cannot be repaired. If one switch is damaged

o r f a u l t y , t h e e n t i r e p o w e r s e a t s w i t c h m o d u l e m u s t

be replaced.

POWER SEAT ADJUSTER AND MOTORS

There are three reversible motors that operate the

p ow e r s ea t a d ju st e r. Th e m ot o r s a r e con n e ct e d t o

w o r m -d r i ve g e a r box es t h a t m ov e t h e s ea t a d ju st e r

through a combination of screw-type drive units.

The front and rear of a seat are operated by differ-

ent motors. They can be ra ised or lowered indepen-

dently of each other. When the center seat switch is

p u s h e d t o t h e U p o r D o w n p o s i t i o n , b o t h t h e f r o n t

and rear motors operate in unison, moving the entire

s ea t u p or d ow n . Th e f or w a r d -r ea r w a r d m ot or i s

op er a t e d b y p us h in g t h e ce nt e r s e a t s w i t ch t o t h e

Fo r w a r d o r R e a r w a r d p o s i t i o n .Wh en a s w i t ch i s a c t u a t ed , a b a t t e ry f eed a n d a

g r o u n d p a t h a r e a p p l i e d t h r o u g h t h e s w i t c h c o n t a c t s

to the motor(s). The motor(s) an d drives opera te to

m ov e t h e s ea t i n t h e s el ect e d d ir ect i on u n t il t h e

s w i t ch i s r e l ea s ed , or u n t il t h e t r a v el l im it of t h e

p o w e r s e a t a d ju s t e r i s r e a c h e d . W h e n t h e s w i t c h i s

moved in the opposite direction, the battery feed and

ground path to the motor(s) are reversed through the

s w i t c h c o n t a c t s . T h i s c a u s e s t h e m o t o r t o r u n i n t h e

opposite direction.

Each motor contains a self-resetting circuit breaker

to protect i t from overload. Consecutive or frequent

resetting of the circuit breakers must not be al lowedt o con t i n ue, or t h e m ot or s m a y b e d a m a g ed . M a k e

the necessary repairs.

Th e p ow e r s ea t a d ju s t er a n d m ot or s ca n n ot b e

repaired, and are serviced only as a complete unit . If

a n y c o m p o n e n t i n t h i s u n i t i s f a u l t y o r d a m a g e d , t h e

entire power seat adjuster and motors assembly must

be replaced.

XJ POWER SEAT SYSTEMS 8R - 1

7/29/2019 EXJ_8R99 jeep xj service manual

2/4

CIRCUIT BREAKER

An automatic resetting circuit breaker in the junc-

t i on bl ock i s u s e d t o p r o t ect t h e p ow e r s ea t s y s t em

ci r cu i t . Th e ci r cu i t br ea k e r ca n p r ot e ct t h e s y s t em

f r om a s h or t ci r cu i t , or f r om a n ov er l oa d con d i t i on

caused by an obstructed or stuck seat adjuster.

Th e ci r cu i t b r ea k e r ca n n ot b e r ep a ir ed a n d , i ff a u l t y o r d a m a g e d , i t m u s t be r e p l a c e d .

DIAGNOSIS AND TESTING

POWER SEAT SYSTEM

B e for e a n y t es t in g of t h e p ow e r s ea t s ys t em i s

a t t e m pt e d , t h e ba t t e r y s h ou l d be f u ll y -ch a r g e d a n d

a l l w i r e h a r n es s con n ect i on s a n d p in s cl ea n e d a n d

t i g h t e n ed t o e n su r e p r op er con t i n u it y a n d g r ou n d s .

For circuit descriptions and diagrams, refer to 8W-63

- P o w e r S e a t i n Gr o u p 8 W - Wi r in g Di a g r a m s .

Wi t h t h e d om e l a mp on , a p pl y t h e pow e r s ea ts w i t ch i n t h e d ir ect i on of t h e f a i lu r e. I f t h e d om e

l a m p d i m s, t h e s ea t m a y b e j a m m in g . C h e ck u n d er

a n d b eh i nd t h e s ea t f or b in d in g or ob st r u ct i on s . I f

the dome lamp does not dim, proceed with testing of

the individual components and circuits.

CIRCUIT BREAKER

F or ci r cu it d es cr i pt i on s a n d d ia g r a m s , r ef er t o

8W-63 - Power Seat in Group 8W - Wiring Diagrams.

(1) Locat e t he correct circuit breaker in the junc-

t i on bl ock . P u l l ou t t h e ci r cu i t br ea k e r s l ig h t l y, bu t

be s u r e t h a t t h e t e r m i n a l s s t i l l con t a ct t h e t e r m in a l s

in the junction block cavities.(2) Connect the negative lead of a 12-volt DC volt-

meter to a good ground.

(3) Wi t h t h e v ol t m et e r p os i t iv e l ea d , ch e ck bot h

terminals of the circuit breaker for battery voltage.

If only one terminal has battery voltage, the circuit

breaker is faulty and must be replaced. If neither ter-

m i na l h a s b a t t e r y v ol t a g e, r ep a i r t h e op en ci r cu it

f rom t h e P ow er D is tr ibu t ion C en t er (P D C ) a s

required.

POWER SEAT ADJUSTER AND MOTORS

F or ci r cu it d es cr i pt i on s a n d d ia g r a m s , r ef er t o

8W-63 - Power Seat in Group 8W - Wiring Diagrams.O pe ra t e t h e p ow e r s ea t s w i t ch t o m o ve a l l t h r ee

seat motors. The sea t should move in each selected

direction. If a motor fai ls t o operate in only one direc-

t i on , m ov e t h e s ea t a s h or t d i st a n ce i n t h e op pos i t e

d i r e c t i o n a n d t e s t a g a i n t o be c e r t a i n t h e a d ju s t e r i s

n o t a t i t s t r a v e l l i m i t . I f o n e o r m o r e o f t h e m o t o r s

op er a t e , s ee t h e d i a g n os i s f or t h e P o w e r S e a t Sw i t ch

i n t h i s g r ou p . I f n o m o t or s op er a t e , p r oce ed a s f ol -

lows:

(1) Test t he circuit brea ker in th e junction block as

d e s c r i b e d i n t h i s g r o u p . I f O K , g o t o S t e p 2 . I f n o t

OK, replace the faulty circuit breaker.

(2) R e mov e t h e p ow e r s ea t s w i t ch a s d e scr i bed i n

t h i s g r ou p. C h eck f or b a t t e ry v ol t a g e a t t h e f u se d

B (+ ) circuit cavity of the power seat switch w ire ha r-

ness connector. If OK, go to Step 3. If not OK, repairthe open circuit to the junction block as required.

(3) C h e ck f or con t i n u i t y bet w e e n t h e g r ou n d ci r -

cuit cavity of the power seat switch wire harness con-

n ect or a n d a g ood gr ou nd . Th er e sh ou ld be

c o n t i n u i t y . I f O K, g o t o St e p 4 . I f n o t O K, r e p a i r t h e

open circuit to ground as required.

(4) Test t he power seat switch a s described in this

group. If the switch tests OK, check the wire harness

for the inoperative motor between the switch and the

motor for shorts or opens. If the circuits check OK,

r ep la c e t h e f a u lt y p ow e r s ea t a d ju s t er a n d m ot or s

a s s e m bl y . I f t h e c i r c u i t s a r e n o t O K, r e p a i r t h e w i r e

h a r n e s s a s r e q u i r e d .

POWER SEAT SWITCH

F or ci r cu it d es cr i pt i on s a n d d ia g r a m s , r ef er t o

8W-63 - Power Seat in Group 8W - Wiring Diagrams.

(1) Remove the power seat switch a s described in

this group.

(2 ) U s e a n o h m m e t e r t o t e s t t h e c o n t i n u i t y o f t h e

switches in each position. See the Power Seat Switch

Continuity chart (Fig. 1). If OK, see the diagnosis for

t h e P ow e r S e a t A dju s t er a n d M ot o r s i n t h i s g r ou p . I f

not OK, replace the faulty power seat switch module.

REMOVAL AND INSTALLATION

POWER SEAT SWITCH

(1) D is con n ect a n d i sol a t e t h e b a t t e r y n eg a t i ve

cable.

(2 ) R e m o v e t h e t h r e e s c r e w s t h a t s e c u r e t h e s e a t

side shield to the outboard seat cushion frame.

(3) P u ll t h e s ea t s id e s h i el d a w a y f r om t h e s ea t

cu s h ion f r a m e f a r e n ou g h t o a cce ss t h e p ow e r s ea t

switch wire harness connector.

(4) U n pl ug t h e p ow e r s ea t s w i t ch w i r e h a r n es s

connector from the switch.

(5) Remove the seat side shield from the vehicle.(6 ) R e m o v e t h e t w o s c r e w s t h a t s e c u r e t h e p o w e r

s e a t s w i t c h t o t h e i n s i d e o f t h e s e a t s i d e s h i e l d (Fi g .

2).

(7) R e m ov e t h e p ow e r s ea t s w i t ch f r om t h e s ea t

side shield.

(8) Re ve rs e t h e r em ov a l p roce du r es t o i n st a l l .

Tighten the mounting screws to 2.2 Nm (20 in. lbs.).

8R - 2 POWER SEAT SYSTEMS XJ

DESCRIPTION AND OPERATION (Continued)

7/29/2019 EXJ_8R99 jeep xj service manual

3/4

POWER SEAT ADJUSTER AND MOTORS

(1 ) M o v e t h e s e a t t o i t s f u l l y r a i s e d a n d f u l l y f o r -

ward position, i f possible.

(2) D is con n ect a n d i sol a t e t h e b a t t e ry n eg a t i vecable.

(3 ) U n p l u g t h e s e a t be l t s w i t c h w i r e h a r n e s s c o n -

n e ct o r f r o m t h e d r i v er s i de s ea t bel t bu ck l e h a l f on

the inboard side of the seat (Fig. 3).

(4) Remove the two screws that secure the front of

t h e s e a t a d ju s t e r f r a m e t o t h e f l o o r p a n s e a t m o u n t -

ing reinforcement (Fig. 4).

(5) R e m ov e t h e s cr e w t h a t s ecu r es t h e ou t boa r d

r e a r o f t h e s e a t a d ju s t e r f r a m e t o t h e f l o o r p a n .

(6 ) R e m o v e t h e n u t t h a t s e c u r e s t h e i n bo a r d r e a r

of t h e s e a t a d ju s t er f r a m e t o t h e s t u d on t h e f l oor

p a n .

(7) Unplug the power seat wire harness connector

from the body wire harness connector.

(8) Remove the driver side power sea t an d a djuster

assembly from the vehicle.

(9) Unplug the power seat wire harness connectors

a t e a c h o f t h e t h r e e p o w e r s e a t m o t o r s .

(10) R em ov e t h e f ou r n u t s t h a t s ecu r e t h e s ea t

a d ju s t er a n d m ot or s a s s em b ly t o t h e s ea t cu s hi on

f r a m e a n d r e m ov e t h e a d ju st e r a n d m ot o r s a s s e m bl y

from the seat (Fig. 5).

(11) R ev er s e t h e r e m ov a l p r oce d ur e s t o i n s t a l l.

Ti g h t en t h e s ea t m ou n t i n g h a r d w a r e a s f ol l ow s :

Fig. 1 Power Seat Switch Continuity

SWITCH POSITIONOFF

VERTICAL UP

VERTICAL DOWN

HORIZONTAL FORWARD

HORIZONTAL AFT

FRONT TILT UP

FRONT TILT DOWN

REAR TILT UP

REAR TILT DOWN

CONTINUITY BETWEEN AFT/FORWARDDOWNTERMINALS SHOWN ASVIEWED FROM REAR OFSWITCHUP

Fig. 2 Power Seat Switch Remove/Install

SEAT SIDE SHIELD POWER SEAT SWITCHSCREWS

Fig. 3 Driver Seat Belt Switch Connector

DRIVER SIDE FRONT SEATSEAT BELT SWITCHCONNECTORBODY WIRE HAR-NESS CONNECTOR

XJ POWER SEAT SYSTEMS 8R - 3

REMOVAL AND INSTALLATION (Continued)

7/29/2019 EXJ_8R99 jeep xj service manual

4/4

S e a t a d ju s t er t o s e a t cu s hi on f r a m e n u t s - 25

Nm (18 ft . lbs.)

Seat adjuster to floor panel screws - 27 Nm (20

ft . lbs.)

Se a t a d ju st e r t o f l oor p a n e l n u t - 40 N m (30 f t .

lbs.).

Fig. 4 Power Seat Remove/Install

NUT DRIVER SIDEFRONT SEATSCREWSTUDSCREW

Fig. 5 Power Seat Adjuster and Motors Remove/Install

POWER SEAT ADJUSTERAND MOTORS SEAT CUSHIONFRAMESEAT CUSHIONFRAME

8R - 4 POWER SEAT SYSTEMS XJ

REMOVAL AND INSTALLATION (Continued)