Subaru Impreza 2004 User manual

FUJI HEAVY INDUSTRIES LTD. G1870GE6
2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX
BODY 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 experienced mechanics.
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.
HVAC SYSTEM
(HEATER, VENTILATOR AND A/C) AC
HVAC SYSTEM (AUTO A/C)
(DIAGNOSTICS) AC(diag)
AIRBAG SYSTEM AB
AIRBAG SYSTEM (DIAGNOSTICS) AB(diag)
SEAT BELT SYSTEM SB
LIGHTING SYSTEM LI
WIPER AND WASHER SYSTEMS WW
ENTERTAINMENT ET
COMMUNICATION SYSTEM COM
GLASS/WINDOWS/MIRRORS GW
BODY STRUCTURE BS
INSTRUMENTATION/DRIVER INFO IDI
SEATS SE
SECURITY AND LOCKS SL
SUNROOF/T-TOP/CONVERTIBLE TOP
(SUNROOF) SR
EXTERIOR/INTERIOR TRIM EI
EXTERIOR BODY PANELS EB

2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX
BODY SECTION
G1870GE6
CRUISE CONTROL SYSTEM CC
CRUISE CONTROL SYSTEM
(DIAGNOSTICS) CC(diag)
IMMOBILIZER (DIAGNOSTICS) IM(diag)

LIGHTING SYSTEM
LI
Page
1. General Description ....................................................................................2
2. Headlight and Tail Light System .................................................................3
3. Front Fog Light System...............................................................................4
4. Rear Fog Light System ...............................................................................5
5. Turn Signal and Hazard Light System ........................................................6
6. Back-up Light System .................................................................................7
7. Stop Light System .......................................................................................8
8. Interior Light System ...................................................................................9
9. Headlight Beam Leveler System...............................................................10
10. Combination Switch (Light) .......................................................................11
11. Combination Base Switch Assembly.........................................................13
12. Headlight Assembly ..................................................................................14
13. Headlight Bulb...........................................................................................16
14. Front Turn Signal Light Bulb .....................................................................17
15. Clearance/Parking Light Bulb....................................................................18
16. Front Fog Light Assembly .........................................................................19
17. Front Fog Light Bulb..................................................................................20
18. Rear Combination Light Assembly............................................................21
19. Brake/Tail Light Bulb .................................................................................22
20. Back-up Light Bulb ....................................................................................23
21. Rear Turn Signal Light Bulb ......................................................................24
22. Rear Fog Light Bulb ..................................................................................25
23. License Plate Light....................................................................................26
24. High-mounted Stop Light ..........................................................................27
25. Side Turn Signal Light...............................................................................28
26. Spot Map Light ..........................................................................................29
27. Room Light................................................................................................30
28. Luggage Room Light.................................................................................31
29. Trunk Room Light......................................................................................32
30. Glove Box Light.........................................................................................33

LI-2
LIGHTING SYSTEM
General Description
1. General Description
A: SPECIFICATIONS
B: PRECAUTIONS
•Before disassembling or reassembling parts, always disconnect the battery ground cable. When replacing
radio, control module, and other parts provided with memory functions, record memory contents before dis-
connecting the battery ground cable. Otherwise, the memory will be erased.
•Reassemble in reverse order of disassembly, unless otherwise indicated.
•Adjust parts to the given specifications.
•Connect the connectors securely during reassembly.
•After reassembly, make sure functional parts operate smoothly.
WARNING:
•Airbag system wiring harness is routed near electrical parts and switches. All airbag system wiring
harnesses and connectors are yellow. Do not use electric test equipment on these circuits.
•Be careful not to damage the airbag system wiring harness when servicing electrical parts and
switches.
C: PREPARATION TOOL
1. GENERAL TOOLS
Headlight 12 V —55 W/60 W (Halogen)
Front turn signal light 12 V —21 W
Side turn signal light 12 V —5 W
Clearance/Parking light 12 V —5 W
Front fog light 12 V —55 W
Rear fog light 12 V —21 W
Rear combination light
Sedan Tail light 12 V —5/21 W
Stop light 12 V —21 W
Wagon Tail/Stop light 12 V —5/21 W
Turn signal light 12 V —21 W
Back-up light 12 V —21 W
License plate light 12 V —5 W
High-mounted stop light Sedan Standard type 12 V —21 W Rear spoiler built-in type 12 V —1.2 W (LED)
Wagon 12 V —10 W
Room light 12 V —8 W
Spot light 12 V —8 W
Luggage room light 12 V —13 W
Trunk room light 12 V —5 W
Glove box light 12 V —1.4 W
TOOL NAME REMARKS
Circuit Tester Used for measuring resistance and voltage.

LI-3
LIGHTING SYSTEM
Headlight and Tail Light System
2. Headlight and Tail Light Sys-
tem
A: WIRING DIAGRAM
1. HEADLIGHT LHD MODEL
<Ref. to WI-213, LHD MODEL, WIRING DIA-
GRAM, Headlight System.>
2. HEADLIGHT RHD MODEL
<Ref. to WI-214, RHD MODEL, WIRING DIA-
GRAM, Headlight System.>
3. CLEARANCE LIGHT AND ILLUMINA-
TION LIGHT LHD MODEL
<Ref. to WI-198, LHD MODEL, WIRING DIA-
GRAM, Clearance Light and Illumination Light Sys-
tem.>
4. CLEARANCE LIGHT AND ILLUMINA-
TION LIGHT RHD WITHOUT ILLUMINATION
CONTROL MODEL
<Ref. to WI-201, RHD WITHOUT ILLUMINATION
CONTROL MODEL, WIRING DIAGRAM, Clear-
ance Light and Illumination Light System.>
5. CLEARANCE LIGHT AND ILLUMINA-
TION LIGHT RHD WITH ILLUMINATION
CONTROL MODEL
<Ref. to WI-204, RHD WITH ILLUMINATION CON-
TROL EXCEPT FOR AUSTRALIA STi MODEL,
WIRING DIAGRAM, Clearance Light and Illumina-
tion Light System.>
6. CLEARANCE LIGHT AND ILLUMINA-
TION LIGHT STi MODEL FOR AUSTRALIA
<Ref. to WI-207, RHD FOR AUSTRALIA STi MOD-
EL, WIRING DIAGRAM, Clearance Light and Illu-
mination Light System.>
B: INSPECTION
1. HEADLIGHT SWITCH
<Ref. to LI-11, INSPECTION, Combination Switch
(Light).>
2. HEADLIGHT RELAY
Measure the headlight relay resistance between
terminals when connecting terminal No. 4 to battery
positive terminal and terminal No. 3 to battery
ground terminal.
3. TAIL AND ILLUMINATION RELAY
Measure the tail and illumination relay resistance
between terminals when connecting terminal No. 4
to battery positive terminal and terminal No. 3 to
battery ground terminal.
Current Terminal No. Standard
Flow 1 and 2 Less than 1 Ω
No flow More than 1 MΩ
Current Terminal No. Standard
Flow 1 and 2 Less than 1 Ω
No flow More than 1 MΩ
LI-00001
(1)
(2)
(1)
(4)
(2)
(3)
(3) (4)
LI-00001
(1)
(2)
(1)
(4)
(2)
(3)
(3) (4)

LI-4
LIGHTING SYSTEM
Front Fog Light System
3. Front Fog Light System
A: WIRING DIAGRAM
1. FRONT FOG LIGHT LHD MODEL
<Ref. to WI-210, LHD MODEL, WIRING DIA-
GRAM, Front Fog Light System.>
2. FRONT FOG LIGHT RHD FOR EUROPE
MODEL
<Ref. to WI-211, RHD FOR EUROPE MODEL,
WIRING DIAGRAM, Front Fog Light System.>
3. FRONT FOG LIGHT RHD EXCEPT FOR
EUROPE MODEL
<Ref. to WI-212, RHD EXCEPT FOR EUROPE
MODEL, WIRING DIAGRAM, Front Fog Light Sys-
tem.>
B: INSPECTION
1. FRONT FOG LIGHT SWITCH
Measure the front fog light switch resistance.
2. FRONT FOG LIGHT RELAY
Measure the front fog light relay resistance be-
tween terminals when connecting terminal No. 4 to
battery positive terminal and terminal No. 3 to bat-
tery ground terminal.
Switch position Terminal No. Standard
OFF 3 and 5 More than 1 MΩ
ON Less than 1 Ω
LI-00051
Current Terminal No. Standard
Flow 1 and 2 Less than 1 Ω
No flow More than 1 MΩ
LI-00001
(1)
(2)
(1)
(4)
(2)
(3)
(3) (4)

LI-5
LIGHTING SYSTEM
Rear Fog Light System
4. Rear Fog Light System
A: WIRING DIAGRAM
1. REAR FOG LIGHT LHD MODEL
<Ref. to WI-240, LHD MODEL, WIRING DIA-
GRAM, Rear Fog Light System.>
2. REAR FOG LIGHT RHD MODEL
<Ref. to WI-241, RHD MODEL, WIRING DIA-
GRAM, Rear Fog Light System.>
B: INSPECTION
1. REAR FOG LIGHT SWITCH
1) Turn the ignition switch to ON.
2) Turn on the headlight or front fog light.
3) Push the rear fog light switch and check if the
rear fog light turns on.
2. REAR FOG LIGHT RELAY
Measure the rear fog light relay resistance between
terminals when connecting terminal No. 4 to battery
positive terminal and terminal No. 3 to battery
ground terminal.
Current Terminal No. Standard
Flow 1 and 2 Less than 1 Ω
No flow More than 1 MΩ
LI-00001
(1)
(2)
(1)
(4)
(2)
(3)
(3) (4)

LI-6
LIGHTING SYSTEM
Turn Signal and Hazard Light System
5. Turn Signal and Hazard Light
System
A: WIRING DIAGRAM
1. TURN SIGNAL LIGHT AND HAZARD
LIGHT LHD MODEL
<Ref. to WI-220, LHD MODEL, WIRING DIA-
GRAM, Turn Signal Light and Hazard Light Sys-
tem.>
2. TURN SIGNAL LIGHT AND HAZARD
LIGHT RHD MODEL
<Ref. to WI-222, RHD MODEL, WIRING DIA-
GRAM, Turn Signal Light and Hazard Light Sys-
tem.>
B: INSPECTION
1. TURN SIGNAL SWITCH
<Ref. to LI-11, INSPECTION, Combination Switch
(Light).>
2. HAZARD SWITCH
Measure the hazard switch resistance.
3. TURN SIGNAL AND HAZARD MODULE
Connect the battery and turn signal light bulb to the
module, as shown in the figure. The module is
properly functioning if it blinks when power is sup-
plied to the circuit.
Switch position Terminal No. Standard
OFF 6 and 7 Less than 1 Ω
ON 1, 3 and 4 Less than 1 Ω
7 and 8 Less than 1 Ω
LI-00002
4321
5678
LI-00003

LI-7
LIGHTING SYSTEM
Back-up Light System
6. Back-up Light System
A: WIRING DIAGRAM
1. BACK-UP LIGHT
<Ref. to WI-197, WIRING DIAGRAM, Back-up
Light System.>
B: INSPECTION
1. BACK-UP LIGHT SWITCH (M/T)
Measure the back-up light switch resistance.
2. INHIBITOR SWITCH (A/T)
Measure the inhibitor switch resistance.
(A) Non-turbo model
(B) Turbo model
Switch position Terminal No. Standard
When shift lever is
set in reverse
position
Turbo model:
2 and 4
Non-turbo model:
1 and 2
Less than 1 Ω
Other positions More than 1 MΩ
LI-00004
(A)
(B)
12
12
34
Switch position Terminal No. Standard
When select lever
is set in “R”range 1 and 2 Less than 1 Ω
Other positions More than 1 MΩ
9
LI-00005
4321
56
78101112

LI-8
LIGHTING SYSTEM
Stop Light System
7. Stop Light System
A: WIRING DIAGRAM
1. STOP LIGHT
<Ref. to WI-219, WIRING DIAGRAM, Stop Light
System.>
B: INSPECTION
1. STOP LIGHT SWITCH
Measure the stop light switch resistance.
(A) Without cruise control
(B) With cruise control
Switch position Terminal No. Standard
When brake pedal
is depressed
1 and 2: Without
cruise control
2 and 3: With
cruise control
Less than 1 Ω
When brake pedal
is released More than 1 MΩ
34
12
12
LI-00064
(A)
(B)

LI-9
LIGHTING SYSTEM
Interior Light System
8. Interior Light System
A: WIRING DIAGRAM
1. INTERIOR LIGHT LHD MODEL
<Ref. to WI-215, LHD MODEL, WIRING DIA-
GRAM, In Compartment Light System.>
2. INTERIOR LIGHT RHD MODEL
<Ref. to WI-217, RHD MODEL, WIRING DIA-
GRAM, In Compartment Light System.>
B: INSPECTION
1. DOOR SWITCH
Measure the door switch resistance.
2. REAR GATE LATCH SWITCH
Measure the rear gate latch switch resistance.
3. TRUNK ROOM LIGHT SWITCH
Measure the trunk room light switch resistance.
Switch position Terminal No. Standard
When door is
opened 1 and 3
Less than 1 Ω
When door is
closed More than 1 MΩ
Switch position Terminal No. Standard
When rear gate is
opened 1 and 2
Less than 1 Ω
When rear gate is
closed More than 1 MΩ
Switch position Terminal No. Standard
When trunk lid is
opened 1 and 2
Less than 1 Ω
When trunk lid is
closed More than 1 MΩ
1
2
3
LI-00007

LI-10
LIGHTING SYSTEM
Headlight Beam Leveler System
9. Headlight Beam Leveler Sys-
tem
A: WIRING DIAGRAM
1. HEADLIGHT BEAM LEVELER
<Ref. to WI-182, WIRING DIAGRAM, Headlight
Beam Leveler System.>
B: INSPECTION
1. HEADLIGHT BEAM LEVELER ACTUA-
TOR
1) Turn on the headlights.
2) Confirm the headlight beam level is lowered by
changing the switch position to 0 - 1 - 2 - 3.
2. HEADLIGHT BEAM LEVELER SWITCH
Connect the battery, headlight beam leveler switch
connector and circuit tester as shown in the figure.
Measure the voltage at each switch position.
Switch position Terminal No. Standard
0 7 (+) and battery (−) Battery voltage
1 6 (+) and battery (−) Battery voltage
2 3 (+) and battery (−) Battery voltage
3 4 (+) and battery (−) Battery voltage
LI-00237
4321
8 7 6 5
v

LI-11
LIGHTING SYSTEM
Combination Switch (Light)
10.Combination Switch (Light)
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Remove the instrument panel lower cover. <Ref.
to EI-43, REMOVAL, Instrument Panel Assembly.>
3) Remove the screws which secure the upper col-
umn cover to lower column cover.
4) Disconnect the connector from combination
switch.
5) Remove the screws which secure the switch,
and then remove the switch.
B: INSTALLATION
Install in the reverse order of removal.
C: INSPECTION
Measure the combination switch resistance.
1. LIGHTING SWITCH
LHD model and RHD for Europe model:
RHD except for Europe model:
LI-00009
LI-00068
(A) LHD model/RHD model (for Europe)
(B) RHD model (Except for Europe)
Switch position Terminal No. Standard
OFF —More than 1 MΩ
Tail 14 and 16 Less than 1 Ω
Head 13, 14 and 16 Less than 1 Ω
Switch position Terminal No. Standard
OFF —More than 1 MΩ
Tail 9 and 15 Less than 1 Ω
Head 9, 14 and 15 Less than 1 Ω
LI-00184
1514131211 10 917 16
6 5 4 3 2 18 7
1514131211 10 917 16
6 5 4 3 2 18 7
(A)
(B)

LI-12
LIGHTING SYSTEM
Combination Switch (Light)
2. DIMMER AND PASSING SWITCH
LHD model and RHD for Europe model:
RHD except for Europe model:
3. TURN SIGNAL SWITCH
LHD model and RHD for Europe model:
RHD except for Europe model:
Switch position Terminal No. Standard
Passing 7, 8 and 16 Less than 1 Ω
Low beam 16 and 17 Less than 1 Ω
High beam 7 and 16 Less than 1 Ω
Switch position Terminal No. Standard
Passing 1, 2 and 9 Less than 1 Ω
Low beam 9 and 10 Less than 1 Ω
High beam 2 and 9 Less than 1 Ω
Switch position Terminal No. Standard
Left 1 and 2 Less than 1 Ω
Neutral —More than 1 MΩ
Right 2 and 3 Less than 1 Ω
Switch position Terminal No. Standard
Left 6 and 7 Less than 1 Ω
Neutral —More than 1 MΩ
Right 7 and 8 Less than 1 Ω

LI-13
LIGHTING SYSTEM
Combination Base Switch Assembly
11.Combination Base Switch
Assembly
A: REMOVAL
1) Remove the driver’s airbag module. <Ref. to AB-
12, REMOVAL, Driver’s Airbag Module.>
2) Remove the steering wheel. <Ref. to PS-23, RE-
MOVAL, Steering Wheel.>
3) Remove the steering column cover.
4) Remove the combination switch. <Ref. to LI-11,
REMOVAL, Combination Switch (Light).> <Ref. to
WW-7, REMOVAL, Combination Switch (Wiper).>
5) Loosen the four screws and remove the roll con-
nector.
6) Loosen the three screws.
7) Disconnect the connector and remove the com-
bination base switch assembly.
B: INSTALLATION
1) Install in the reverse order of removal.
2) Align the attaching direction of roll connector
with the steering wheel, before installation of steer-
ing wheel. <Ref. to AB-18, ADJUSTMENT, Roll
Connector.>
C: INSPECTION
1. COMBINATION BASE SWITCH ASSEM-
BLY
Perform the inspection for the following items and
replace with a new one, if any damage is found.
•Crack or deformation of combination base switch
assembly or roll connector
2. PARKING SWITCH
Measure the parking switch resistance.
LI-00181
Switch position Terminal No. Standard
OFF 2 and 4 Less than 1 Ω
ON 1 and 4 Less than 1 Ω
LI-00183
12
34

LI-14
LIGHTING SYSTEM
Headlight Assembly
12.Headlight Assembly
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Remove the duct (A) (when right side headlight
is removed).
3) Remove the front grille and bumper upper clips.
<Ref. to EI-18, REMOVAL, Front Grille.>
4) Disconnect each harness connector.
5) Remove the three bolts and disengage the clips,
and then detach the headlight assembly.
B: INSTALLATION
Install in the reverse order of removal.
C: ADJUSTMENT
1. HEADLIGHT AIMING
CAUTION:
Turn off the light before adjusting headlight
aiming. If the light is necessary to check aim-
ing, do not turn on for more than 2 minutes.
NOTE:
Before checking the headlight aiming, be sure of
the following:
•The area around the headlight has not sustained
any accident, damage or other type of deformation.
•Vehicle is parked on level ground.
•The inflation pressure of tires is correct.
•Vehicle’s gas tank is fully charged.
•Bounce the vehicle several times to normalize
the suspension.
•Make certain that someone is seated in the driv-
er’s seat.
Turn the headlights on and then adjust the low
beam pattern to the following positions on the
screen.
NOTE:
•Set the headlight leveler switch to “0”position.
•Adjust the vertical aim (A) first, then horizontal
aim (B).
LI-00190
(A)
LI-00191
LI-00194
(B)
(A)

LI-15
LIGHTING SYSTEM
Headlight Assembly
This illustration is for LHD model.
The pattern for RHD model is symmetrically opposite.
(A) Vehicle center (B) Bulb center making
W mm (in)
H mm (in)
h mm (in) at 3 m (10 ft)
Sedan Wagon
TS GX, RS, WRX
STi TS GX, WRX OUTBACK
1,279 (50.35) 644 (25.35) 639 (25.16) 644 (25.35) 639 (25.16) 649 (25.55) 30 (1.18)
LI-00054
H
H
W1
W
W
W2
W2
W1
(A)
(A)
3m (10 ft)
(B)
h
h

LI-16
LIGHTING SYSTEM
Headlight Bulb
13.Headlight Bulb
A: REMOVAL
CAUTION:
•Because the halogen bulb operates at a high
temperature, dirt and oil on the bulb surface re-
duces the bulb’s service life. Hold the flange
portion when replacing the bulb. Never touch
the glass portion.
•Do not leave the headlight without a bulb for
a long time. Dust, moisture, etc. entering the
headlight may affect its performance.
1) Disconnect the ground cable from battery.
2) Remove the air intake duct (A) (when right side
headlight bulb is removed).
3) Disconnect the harness connector.
4) Remove the bulb ASSY. To remove the low
beam, remove the back cover, and then go to Step
5.
5) Remove the light bulb retaining spring (A) to re-
move the bulb.
B: INSTALLATION
Install in the reverse order of removal.
CAUTION:
Attach the rubber cap with letters TOP on the
top so the drain hole will be on the lower side.
C: INSPECTION
1) Visually check the bulb for blow out.
2) Check the bulb specification. <Ref. to LI-2,
SPECIFICATIONS, General Description.>
3) If NG, replace the bulb with a new one.
(A) High beam
(B) Low beam
LI-00190
(A)
LI-00195
(A)
(B)
LI-00196
(A)

LI-17
LIGHTING SYSTEM
Front Turn Signal Light Bulb
14.Front Turn Signal Light Bulb
A: REMOVAL
Turn the socket (A) and remove the bulb.
B: INSTALLATION
Install in the reverse order of removal.
C: INSPECTION
1) Visually check the bulb for blow out.
2) Check the bulb specification. <Ref. to LI-2,
SPECIFICATIONS, General Description.>
3) If NG, replace the bulb with a new one.
LI-00346
(A)

LI-18
LIGHTING SYSTEM
Clearance/Parking Light Bulb
15.Clearance/Parking Light Bulb
A: REMOVAL
1) Remove the headlight assembly. <Ref. to LI-14,
REMOVAL, Headlight Assembly.>
2) Turn the socket (A) and remove the bulb.
B: INSTALLATION
Install in the reverse order of removal.
C: INSPECTION
1) Visually check the bulb for blow out.
2) Check the bulb specification. <Ref. to LI-2,
SPECIFICATIONS, General Description.>
3) If NG, replace the bulb with a new one.
LI-00347
(A)