Subaru 2002 Impreza User manual

2002 IMPREZA SERVICE MANUAL QUICK REFERENCEINDEX
WIRING SYSTEM SECTION
This service manual has been prepared
to provide SUBARU service personnel
with the necessary information and data
for the correct maintenance and repair
of SUBARU vehicles.
This manual includes the procedures
for maintenance, disassembling, reas-
sembling, inspection and adjustment of
components and diagnostics for guid-
ance of experiencedmechanics.
Please peruse and utilize this manual
fully
to ensure complete repair work for
satisfying our customers by keeping
their vehicle in optimum condition.
When replacement of parts during
repair work is needed, be sure
to use
SUBARU genuine parts.
All information, illustration and specifi-
cations contained in this manual are
based on the latest product information
available at the time of publication
approval.
G1830BE7
FUJI
HEAVY INDUSTRIESLTD.

WIRING SYSTEM
WI.
1 .
2 .
3 .
4 .
5 .
6 .
7 .
8 .
9 .
10 .
11 .
12 .
13 .
14 .
15 .
16 .
17 .
18 .
19 .
20 .
21 .
22 .
23 .
24 .
25 .
26 .
27 .
28 .
29 .
30 .
31 .
32 .
33 .
34 .
35 .
36 .
37 .
38 .
39 .
40 .
41 .
42 .
43 .
Page
Basic Diagnostics Procedure ...................................................................... 3
Working Precautions
................................................................................. 12
Super MultipleJunction (SMJ)
.................................................................. 13
Power Supply Routing
............................................................................... 15
Ground Distribution
................................................................................... 22
Airbag System
........................................................................................... 31
Air Conditioning System
............................................................................ 34
Anti-lock Brake System
............................................................................. 36
Audio System
............................................................................................ 52
Clock System
............................................................................................ 55
Compass Mirror System ............................................................................ 60
Cruise Control System
.............................................................................. 61
Door Lock System
..................................................................................... 64
Engine Electrical System
.......................................................................... 66
Horn System
............................................................................................. 89
A/T Control System ................................................................................... 39
A/T Shift Lock Control System .................................................................. 50
Charging System ....................................................................................... 54
Combination Meter .................................................................................... 56
Engine Coolant Temperature Gauge System
........................................... 65
Fuel Gauge System
.................................................................................. 87
Front Accessory Power Supply System
.................................................... 88
Keyless Entry System
............................................................................... 90
Back-up Light System
............................................................................... 93
Clearance Light and Illumination Light System
......................................... 94
Front Fog Light System
............................................................................. 97
Headlight System
...................................................................................... 98
InCompartment Light System ................................................................. 101
Stop Light System ................................................................................... 103
Turn Signal Light and Hazard Light System
............................................ 104
Outside Temperature Display System
.................................................... 107
Parking Brake and Brake Fluid LevelWarning System
.......................... 108
PowerWindow System
........................................................................... 109
Radiator Fan System
.............................................................................. 113
Oil PressureWarning Light System
........................................................ 106
Rear Accessory Power Supply System
................................................... 116
RearWindow Defogger System
.............................................................. 117
Remote Controlled Rearview Mirror System
........................................... 118
Seat Belt Warning and KeyWarning System
.......................................... 119
Seat Heater System
................................................................................ 120
Starter System
........................................................................................ 124
Wiper and Washer System (Front)
.......................................................... 127
Security System
...................................................................................... 121

WIRING SYSTEM
44 .
45 .
46 .
47 .
40 .
49 .
50 .
51 .
52 .
53 .
54 .
Wiper and Washer System (Rear) .......................................................... 128
Overall Systems
...................................................................................... 129
Front Wiring Harness
.............................................................................. 130
BulkheadWiring Harness (In Engine
Room) .......................................... 132
Bulkhead Wiring Harness (In Compartment)
.......................................... 136
EngineWiring HarnessandTransmission Cord
..................................... 139
Rear Wiring Harness, Bulkhead wiring Harness, Roof Cord and Fuel Tank Cord ..... 144
RearWiring Harnessand Trunk Lid Cord
............................................... 148
RearWiring Harness and Rear Gate Cord
............................................. 150
Instrument Panel Wiring Harness
........................................................... 143
Door Cord
................................................................................................ 146
WI-2

m
BASIC DIAGNOSTICS PROCEDURE
WIRING SYSTEM
Switch Position
1. Basic DiagnosticsProcedure
A: BASIC PROCEDURES
1. GENERAL
The most importantpurposeof diagnosticsisto de-
termine which part is malfunctioning quickly, to
save time and labor.
TOM
Determinewhat the problemis based on the symp-
tom.
3. PROBABLE CAUSE OF TROUBLE
Look at the wiring diagram and check the system’s
circuit. Then check the switch, relay, fuse, ground,
etc.
4. LOCATIONAND REPAIR OF TROUBLE
1) Usingthe diagnostics narrow down the causes.
2) If necessary, use a voltmeter, ohmmeter, etc.
3) Before replacing certain component parts
(switch, relay, etc.), check the power supply,
ground, for open wiring harness, poor connectors,
etc.
If no problems are encountered, check the
component parts.
TION
After repairing, ensure that the system operates
properly.
B: BASIC INSPECTION
1. VOLTAGE MEASUREMENT
1) Usinga voltmeter,connectthe negativeleadto a
good ground point or negative battery terminal and
the positiveleadto theconnectoror componentter-
minal.
2) Contact the positive probe of the voltmeter on
connector (A).
The voltmeter will indicate a voltage.
3) Shift the positive probe to connector (6). The
voltmeter will indicate no voltage.
2. IDENTIFICATIONOF TROUBLE SYMP-
5. CONFIRMATIONOF SYSTEM OPERA-
Switch Light
123456
4) With the test set-up held as it is, turn the switch
ON. The voltmeterwill indicatea voltage and,at the
same time, the light will come on.
5) The circuit is in good order. If a problem such as
a lamp failing to light occurs, use the procedures
outlined above to track down the malfunction.
2. CIRCUIT CONTINUITYCHECKS
1) Disconnectthe battery terminal or connector so
there is no voltage between the check points.
Contact the two leads
of an ohmmeter to each of
the check points.
If the circuit has diodes, reversethe two leads and
check again.
2) Use an ohmmeter to check for diode continuity.
When contacting the negative lead to the diode
positive side and the positive lead to the negative
side, there should be continuity.
When contacting the two leads in reverse, there
should beno continuity.
Continuity No continuity
G6M0207
3) Symbol “0-0” indicates that continuity exists
between two points or terminals. For example,
when a switch position is at
“3”, continuity exists
among terminals
1, 3 and 6, as shown in the table
below.
B6M0749
H6M051
OA
WI-3

I
BASIC DIAGNOSTICSPROCEDURE
WIRING SYSTEM
3. HOW TO DETERMINEAN OPEN CIR-
CUIT
1) Voltmeter Method:
An open circuit is determined by measuring the
voltagebetween respectiveconnectorsandground
usinga voltmeter, starting with the connector clos-
est to the powersupply. The power supply must be
turned
ON so that currentflows inthe circuit. If volt-
age is not present between a particular connector
and ground,the circuit betweenthat connector and
the previous connector is open.
NO voltage is present
--
--
-
Voltage is present G6M0208
2) Ohmmeter method:
Disconnectall connectorsaffected, and check con-
tinuity in the wiring between adjacent connectors.
When the ohmmeter indicates “infinite”, the wiring
is open.
7\
Open circuit
11
I
Continuity exists. Continuity
does not exist.
G6M0209
4. HOW TO DETERMINE A SHORT CIR-
CUIT
1) Test lamp method:
Connect a test lamp (rated at approximately
3
watts) in place of the blown fuse and allow current
to flow through the circuit. Disconnectone connec-
tor at atime fromthe circuit,startingwith theone
lo-
cated farthest from the power supply. If the test
lamp goes out when a connector is disconnected,
the wiring between that connection and the next
connector (farther from the power supply) is short-
ed.
Test lamp
-&
G6M0210
2) Ohmmeter method:
Disconnectall affectedconnectors,andcheck con-
tinuity between each connector and ground. When
the ohmmeter indicates continuity between a par-
ticular connector and ground, that connector is
shorted.
,- Shorted connector
pl Continuity qq exists.
t- - Continuity does not exist. .I-
G6M0211
WI-4

BASIC DIAGNOSTICS PROCEDURE
WIRING SYSTEM
C: HOW TO READWIRING DIAGRAMS
1. WIRING DIAGRAM
The wiring diagramof each system is illustrated so that you can understandthe paththroughwhich the elec-
tric current flows from the battery.
Sketches and codes are used in the diagrams. They should readas follows:
Eachconnector and itsterminal positionare indicatedbya sketchof the connectorina disconnectedstate
which isviewedfrom the front.
Viewed from this direction
G6M019:
The number of poles or pins, presence of a lock, and pin number of each terminal are indicated in the
sketch
of eachconnector. Inthe sketch, the highest polenumberrefers to the numberof poleswhich the con-
nector has. For example, the sketchof the connector shown in figure indicates the connectorhas
9 poles.
Connector used in vehicle
G6M0194
G6M0195
Connector shown in wiring diagram
Sketch
Double frames
Indicates the number
of poles.
G6M0196
Indicates a
lock is included.
\
LSingle frame
G6M0197
Symbol
G6M0198
Numberof poles
Numberedin order from upper
right to lower
left.
Numberedin order from upper
left to lower right.
WI-5

BASIC DIAGNOSTICSPROCEDURE
I
WIRING SYSTEM
Color code
When one set of connectors is viewed from the
front side, the pole numbers of one connector are
symmetrical
to those of the other. When these two
connectors are connected as a unit, the poles
which havethe same number arejoined.
Color
Electricalwiring harness:
The connectors are numberedalong with the num-
ber of poles, external colors, and mating connec-
tions inthe accompanying list.
The sketch of each connector in the wiring dia-
gram usually shows the
(A) side of the connector.
The relationship between the wire color, terminal
number and connector is described in the figure.
NOTE:
A wire which runs in one directionfrom a connector
terminalsometimesmay haveadifferentcolorfrom
that which runs in the other direction from that ter-
minal.
L
I
-__________
Wire color:
BR (No. 1 terminal)
Blue
RW (No. 3 terminal) H6M0509A
Inthe wiring diagram, connectors which have no
terminal number refer
to one-pole types. Sketches
of these connectors are omitted intentionally.
G
R
W
Br
Green
Red
White
Brown
G6M0216
Li
Light green
I B I Black I
Gr
I Y I Yellow I
Gray
Or Orange
I P I Pink I
Lb
Liaht Blue
v
Violet
Sealed wire
SA-
7-w
Sealed (Inner)
R
SB
G6M0201
Sealed (Outer)
WI-6
I

BASIC DIAGNOSTICS PROCEDURE
WIRING SYSTEM
0.3 I 7/0.26 1 1.8
The wire color code, which consists of two letters
(or three letters including Br or Lg), indicates the
standard color (base color of the wire covering) by
its first letter and the stripe marking by its second
letter.
7
EMarkingcolor: Black
YE
_-
Reference color: Yellow
0.85
1.25
2
3
G6M0202
11/0.32 2.4 (or 2.2) 16
16/0.32 2.7 (or 2.5) 21
26/0.32 3.1
(or 2.9) 28
41/0.32 3.8 (or3.6) 38
The table lists the nominal sectional areas and
allowable currents of the wires.
CAUTION:
When replacing or repairinga wire, be sure to
use the
same size and type of the wire which
was originally used.
NOTE:
The allowable current in the table indicates the
tolerable amperage
of each wire at an ambient
temperatureof
40°C (1 04°F).
The allowable current changes with ambient
temperature. Also, it changes if a bundle of more
than two wires is used.
Nominal No. of
sectional strands/
strand
diameter
Outside
diameter of
finished
wiring mm
Allowable
current
Amps/
40°C
(1 04°F)
0.5
I 7/0.32 I 2.2 (or2.0) I 12 I
0.75 I 30/0.18 I 2.6 (or2.4) I 16 I
Each unit isdirectly groundedto the bodyor indi-
rectly grounds through a harness ground terminal.
Different symbols are used inthe wiring diagramto
identify the two grounding systems.
1
Direct ground Indirect terminal
ground G6M0203
The ground points shown in the wiring diagram
referto the following:
NOTE:
All wiring harnesses are provided with a ground
point which should be securely connected.
I
@ : Body ground
@ : Engine ground
@ : Radio ground
: Rear defogger ground
B6M1420P
5 I 6510.32 I 4.6 (or4.4) I 51 I
8 I 50/0.45 I 5.5 I 67 I
WI-7

BASIC DIAGNOSTICS PROCEDURE
WIRING SYSTEM
Relays are classified as normally-openor normally-closed. The normally-closedrelay has one or more
contacts.
The wiring diagramshowsthe relay mode when the energizing circuit is
OFF.
Relay type
Mixed type 6-pole
Eneraizina circuit
OFF
Energizing circuit ON
I I
Key to symbols:
0 + : Current flows.
X : Current does not flow.
B6M0748
WI-8

m
BASIC DIAGNOSTICS PROCEDURE
WIRING SYSTEM
E
T
D
~ ~
Each connector number shown inthe wiring dia-
gramcorrespondsto that inthe wiring harness.The
location of each connector in the actual vehicle is
determined by reading the first character of the
connector(forexample,a
“F’ for F8, ‘‘i” for il6,etc.)
and the type of wiring harness.
Thefirst characterof each connector numberrefers
to the area or system
of the vehicle.
I Symbol I Wiring harness and cord I
Enginewiring harness
Transmissioncord, Rearoxygen sensor cord
Doorcord
LH & RH,
Reardoor cord LH i3 RH, Rear gate cord
I F I Front wiring harness I
I B 1 Bulkheadwiring harness I
I
i 1 Instrumentpanelwiring harness I
Rearwiring harness,
Fueltank cord,
Roof cord
Each connector number
shown in wiring diagram
--
FRONTTURN SIGNAL
corresponds to that in
LIGHT LH (UPPER)
FRONTTURN SIGNAL
LIGHT LH(LOWER)
c;;>(GRAV)
@(GRAV
m B6M1561A
WI-9

BASIC DIAGNOSTICS PROCEDURE
WIRING SYSTEM
D: SYMBOLS IN WIRING DIAGRAMS
A numberof symbols are used in each wiring diagram to easily identify parts or circuits.
YI1”F”e€BOI,UB, WIRE TRACING
ON EXTENDED
WIRING DIAGRAMS
RELAY
SYMBOLS
OF
UlRE
ZONNECTION
4ND CROSSING
DIODE
FUSE No.
8. RATING
-177
CONNECTOR-1
POWER SUPPLY
fi fi /ROUTING
.CONNECTOR-2
CONNECTOR
B6M1562A
SKETCH
1. RELAY 4. FUSE NO. & RATING
A symbol used to indicate a relay.
The sketch of the connector indicatesthe one-pole
types.
3. WIRING CONNECTION
Some wiring diagrams are indicated in foldouts for
convenience. Wiring destinations are indicated
where necessary by corresponding symbols (as
when two pages are neededfor clear indication).
2. CONNECTOR-I
The “FUSE No. & RATING” corresponds with that
used in the fuse box (main fuse box, fuse and joint
box).
Eachconnector is indicated by a symbol.
Each terminal number is indicated in the corre-
sponding wiring diagram in an abbreviated form.
For example, terminal number “C2” refers to No.
2 terminal of connector (C: F41) shown in the con-
nector sketch.
5. CONNECTOR-2
WI-I 0

BASIC DIAGNOSTICS PROCEDURE
WIRING SYSTEM
Abbr.
6. CONNECTOR SKETCH
Each connector sketch clearly identifies the
shape and color of a connector as well as terminal
locations. Non-colored connectors are indicated in
naturalcolor.
When morethan two types of connector number
are indicated in a connector sketch, it means that
the same type connectors are used.
7. GROUND
Each grounding point can be located easily by re-
ferring to the corresponding wiring harness.
8. DIODE
A symbol is usedto indicate a diode.
9. WIRE TRACINGON EXTENDEDWIRING
DIAGRAMS
For a wiring diagram extending over at least two
pages,a symbol (consistingof thesamecharacters
with arrows), facilitates wire tracing from one page
to the next.
At-+
A, B ++ B
10.SYMBOLS OF WIRE CONNECTIONAND
CROSSING
Full name
Symbol
+
NC
AD
NS
AT
AU
+B
Symbol
-I-
Air Conditioning
Auto Down
Air suspension
Automatic Transmission
Auto Up
Battery
Refers to wires which are con-
nected and branched at the
“dot” point.
Refers
to wires which are
crossed but not connected.
B6M0750A
MIB
MG
~~~
11.POWER SUPPLY ROUTING
A symbol is used to indicate the power supply in
eachwiring diagram.
“MB-5”, “MB-6”, etc., which are used as power-
supply symbols throughout the text, correspond
with those shown in the POWER SUPPLY ROUT-
ING in the wiring diagram.
Accordingly, using the POWER SUPPLY ROUT-
INGandwiring diagrams permitsservice personnel
to understandthe entire electricalarrangementof a
system.
Main Fuse Box
Maanet
ST
sw
I ACC I Accessory I
Starter
Switch
UP
WASH
I DN 1 Down I
UP
Washer
E I Ground
F/B
I Fuse&Joint Box
I
FLI .5
I Fusiblelink 1.5 mm2
IG
I lanition
I Illumi. I Illumination I
I LH I Left Hand I
Lo I Low
M
I Motor
r Mi I Middle I
OP I Optional Parts
PASS
1 Passing
RH I Right Hand
SBF
I Slow Blow Fuse
WI-I 1

WORKING PRECAUTIONS
WIRING SYSTEM
2. Working Precautions
A: PRECAUTIONSWHEN WORKING
WITH THE PARTS MOUNTEDON
THE VEHICLE
1) When working under a vehicle which is jacked-
up, always be sure to use safety stands.
2) The parking brake must always be applied dur-
ing working.
Also, in automatic transmission vehi-
cles, keep the select lever set to the P (Parking)
range.
3) Be sure the workshop is properly ventilated
when runningthe engine. Further,becareful not to
touch the belt or fan while the engine is operating.
4) Becareful notto touch hot metal parts, especial-
ly the radiatorand exhaust system immediately af-
ter the engine has been turned off.
B: PRECAUTIONS INTROUBLE DI-
AGNOSIS AND REPAIR
OF ELEC-
1) The batterycable mustbedisconnectedfromthe
battery's
(-) terminal, and the ignition switch must
be set to the
OFF position, unless otherwise re-
quired by the diagnostics.
2) Securely fasten the wiring harness with clamps
andslips
so that the harnessdoes not interferewith
the body end parts or edges and bolts or screws.
3) When installing parts, be careful not to catch
them on the wiring harness.
4) When disconnectinga connector, do not pull the
wires, but pull while holdingthe connector body.
TRIC PARTS
/
Correct
/ Wrong
G6M0212
5) Some connectors are provided with a lock. One
type of such a connector is disconnected by push-
ing the lock, and the other, by moving the lock up.
In either type the lock shape must be identified be-
fore attempting to disconnect the connector.
To connect, insert the connector until it snaps and
confirm that it is tightly connected.
Example
LEFT
PUSH
PUSH
-&
PUSH
G6M0212
6) When checking continuity between connector
terminals,or measuringvoltage acrossthe terminal
and ground, always contact tester probe@)on ter-
minalsfrom the wiring connectionside.
If the probe
istoo thick to gainaccesstothe terminal, use"mini"
test leads.
To checkwater-proofconnectors (whichare notac-
cessible from the wiring side), contact test probes
on the terminal side being careful not to bend or
damage the terminals.
Tester probes
1 "Mini" test leads
G6M0214
7) Sensors,relays,electrical unit,etc.,are sensitive
to strong impacts.
Handlethem with care
so that they are notdropped
or mishandled.
WI-I 2

WIRINGSYSTEM
SUPER MULTIPLEJUNCTION (SMJ)
3. Super MultipleJunction (SMJ)
A: HOW TO USE SUPER MULTIPLEJUNCTION (SMJ)
The “SMJ” indicated in wiring diagramsisshown in a simplified form.
B: TERMINAL ARRANGEMENT
BulkheadWiring Harness w FrontWiring Harness
@ 40 Poles (Gray)
Bl-$pj
J4 J5
@ 40 Poles (Gray)
c5c4 83 c2c1
I I
BO0369
WI-13

WIRING SYSTEM
SUP E R MULTIPLEJUNCTlON (SMJ)
--
C: INSTALLATION
--\ \ \\
Tighteningtorque:
NOTE:
Align the cutout portion of one connector with
that of other beforetightening the connecting bolt.
Do nottighten the boltexcessivelysince this may
deform the connectors.
T: 4.4 N.m (0.45 kgf-m, 3.3 ft-lb)
D: EXPLANATION OF SMJ SHOWN INTHE WIRING DIAGRAM
I Y,
WI-I 4

POWER SUPPLY ROUTING
WIRING SYSTEM
4. Power Supply Routing
A: SCHEMATIC
MAIN FUSE BOX (M/B)
MAIN FAN -
20A
SUB FAN -
20A
FUSE & RELAY BOX (NB)
I
GUOI-20A
WI-I 5

POWER SUPPLY ROUTING
WIRING SYSTEM
- BATTERY CURRENT
= CURRENT FROMIGNITION
- OTHER CURRENTS
SWITCH IGTERMINAL
= CURRENT FROM IGNITION
SWITCHACCTERMINAL
l3L- GENERATOR 1 [BW
SBF HOLDER
1 1
BATTERY
n
MAIN FUSE BOX (W)
I
4
P
R
d
c
"!
2
1
* *
U U
GU01-208
WI-I 6

WIRING SYSTEM
POWER SUPPLY ROUTING
MAIN FUSE BOX (WB)
4
::
m
2
v)
4
5:
m
2
v)
HORN
RELAY
L
I
J
@(BLACK) @(BLACK) @
5678
GUOl-20C
WI-17

POWER SUPPLY ROUTING
WIRING SYSTEM
I L
FUSERELAY BOX (F/B) & L
A:@
E:@
C:@
D:@
E:
@
F: @
.:a r
TRAILER
CONNECTOR
pm-+f=giT>
'I
-
K
m Y
-I
m
W
m
U
I
m
~~ z N - TAIL &
ILLUMI-
NATION
RELAY
I
N
6
m
K
rr
P
d
3EFO-
3GER
3ELAY
L
=I
.(
F: F40 (BROWN) E: @ (GRAY)
A: @ (BLUE) 0
G:@ (GRAY)
E:@ (BLUE)
D:@
mq
GUOl-20D
WI-I 8

WIRING SYSTEM
POWER SUPPLY ROUTING
IGNITION SWITCH
I
I
ll I
IGNITION RELAY
I
m
RELAY BLOCK(BLACK)
GUOl-20E
WI-I 9