sensor SUBARU LEGACY 1996 Service Repair Manual

10AK4
CHECK ABSCM.
1) Connect all connectors.
2) Erase the memory.
3) Perform inspection mode.
4) Read out the trouble code.
: Is the same trouble code as in the current
diagnosis still being output?
: Replace ABSCM.
: Go to next.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
B4M0912A
10AK5CHECK BROKEN WIRE IN G SENSOR
OUTPUT HARNESS AND GROUND HAR-
NESS.
1) Turn ignition switch to OFF.
2) Disconnect connector from ABSCM.
3) Measure resistance between ABSCM connector termi-
nals.
: Connector & terminal
(F49) No. 7—No. 45
Is resistance 4.6±0.3 kΩ?
: Go to step10AK6.
: Repair harness between G sensor and ABSCM.
269
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

B4M0915
10AK6
CHECK G SENSOR.
1) Remove console box.
2) Remove G sensor from vehicle.
3) Connect connector to G sensor.
4) Connect connector to ABSCM.
5) Turn ignition switch to ON.
6) Measure voltage between G sensor connector termi-
nals.
: Connector & terminal
(P11) No. 2 (+)—No.1()
Is voltage 2.3±0.2 V when G sensor is hori-
zontal?
: Go to next.
: Replace G sensor.
B4M0917A
: Connector & terminal
(P11) No. 2 (+)—No.1()
Is voltage 3.9±0.2 V when G sensor is
inclined forwards to 90°?
: Go to next.
: Replace G sensor.
B4M0918A
: Connector & terminal
(P11) No. 2 (+)—No.1()
Is voltage 0.7±0.2 V when G sensor is
inclined backwards to 90°?
: Go to step10AK7.
: Replace G sensor.
270
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

11. General Diagnostics Table
A: SYMPTOMS AND PROBABLE CAUSES
Symptom Probable faulty units/parts
Vehicle instability during brakingVehicle pulls to either side.
Hydraulic unit (solenoid valve)

ABS sensor

Brake (caliper & piston, pads)

Wheel alignment

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections

Road surface (uneven, camber)
Vehicle spins.
Hydraulic unit (solenoid valve)

ABS sensor

Brake (pads)

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections
Poor brakingLong braking/stopping distance
Hydraulic unit (solenoid valve)

Brake (pads)

Air in brake line

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections
Wheel locks.
Hydraulic unit (solenoid valve, motor)

ABS sensor

Incorrect wiring or piping connections
Brake dragging
Hydraulic unit (solenoid valve)

ABS sensor

Master cylinder

Brake (caliper & piston)

Parking brake

Axle & wheels

Brake pedal play
Long brake pedal stroke
Air in brake line

Brake pedal play
Vehicle pitching
Suspension play or fatigue (reduced damping)

Incorrect wiring or piping connections

Road surface (uneven)
Unstable or uneven braking
Hydraulic unit (solenoid valve)

ABS sensor

Brake (caliper & piston, pads)

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections

Road surface (uneven)
Vibration and/or noise (while
driving on slippery roads)Excessive pedal vibration
Incorrect wiring or piping connections

Road surface (uneven)
Noise from hydraulic unit
Hydraulic unit (mount bushing)

ABS sensor

Brake piping
Noise from front of vehicle
Hydraulic unit (mount bushing)

ABS sensor

Master cylinder

Brake (caliper & piston, pads, rotor)

Brake piping

Brake booster & check valve

Suspension play or fatigue
Noise from rear of vehicle
ABS sensor

Brake (caliper & piston, pads, rotor)

Parking brake

Brake piping

Suspension play or fatigue
272
4-4cBRAKES [ABS 5.3 TYPE]
11. General Diagnostics Table

D: LIST OF TROUBLE CODES
1. TROUBLE CODES
Trouble code/Contents of troubles Memory function Contents of diagnosis Page
02 Provided.1) Front sensor harness is shorted.
2) Airbag main harness is shorted.
3) Airbag module harness (Dr/Ps) is shorted.
4) Roll connector is shorted.
5) Airbag control module is faulty.16
03 Provided.1) Front sensor harness circuit is open.
2) Front sensor unit circuit is open.18
04 Provided.1) Airbag main harness circuit is shorted.
2) Airbag module harness (Ps) circuit is shorted.
3) Airbag control module is faulty.19
11 Provided.1) Airbag control module is faulty.
2) Airbag main harness circuit is open.
3) Fuse No. 8 is blown.
4) Body harness circuit is open.20
12 Provided.1) Airbag main harness circuit is open.
2) Airbag module harness (Dr) circuit is open.
3) Roll connector circuit is open.
4) Airbag control module is faulty.22
13 Provided.1) Airbag main harness circuit is shorted.
2) Airbag module harness (Dr) is shorted.
3) Roll connector circuit is shorted.
4) Airbag control module is faulty.23
14 Not provided.1) (AB9) and (AB10) are not connected properly.
2) (AB2) and (AB7) are not connected properly.
3) (AB3) and (AB8) are not connected properly.
4) (AB4), (AB5) and (AB6) are not connected
properly to airbag control module.24
21 Provided. Airbag control module is faulty. 26
22 Provided.1) Airbag main harness circuit is open.
2) Airbag module harness (Ps) circuit is open.
3) Airbag control module is faulty.27
23 Provided.1) Airbag main harness is shorted to power supply.
2) Front sensor harness is shorted to power supply.
3) Airbag module harness (Dr/Ps) is damaged.
4) Roll connector is shorted to power supply.
5) Airbag control module is faulty.28
24 Provided.1) Airbag main harness circuit is open.
2) Airbag module harness (Dr) circuit is open.
3) Roll connector circuit is open.
4) Airbag control module is faulty.
5) Above diagnosis plus other faulty of airbag
modular parts.30
31 Not provided.1) Airbag control module is faulty.
2) Airbag main harness circuit is open.
3) Fuse No. 16 is blown.
4) Body harness circuit is open.32
32 Provided.1) Airbag main harness circuit is open.
2) Airbag module harness (Ps) circuit is open.
3) Airbag control module is faulty.
4) Above diagnosis plus other faulty of airbag
modular parts.34
NOTE: Dr: Driver side Ps: Passenger side
10
5-5SUPPLEMENTAL RESTRAINT SYSTEM
4. Diagnostics Chart for On-board Diagnostic System

G5M0558
1. FRONT SENSOR AND HARNESS INSPECTION
1) Disconnect connectors (AB4) and (AB5) from airbag
control module.
2) Connect connectors (AB4) and (AB5) to connector (8B)
of test harness B2.
3) Measure resistance between connector (5B) terminal
indicated.
(5B) Terminal / Specified resistance:
(RH: AB4): No. 17 — No. 18 / 1.4 — 1.6 kΩ
(LH: AB5): No. 15 — No. 16 / 1.4 — 1.6 kΩ
4) Measure resistance between each connector (5B) ter-
minal and body.
(5B) Terminal / Specified resistance:
(RH: AB4): No. 17 — Body/1MΩ, or more
No.18—Body/1MΩ, or more
(LH: AB5): No. 15 — Body/1MΩ, or more
No.16—Body/1MΩ, or more
G5M0559
2. AIRBAG MAIN HARNESS INSPECTION
1) Disconnect connector (AB6) from airbag control module
, and connect (AB6) to test harness
B2 connector (8B).
2) Measure resistance between each (5B) terminal and
body.
(5B) Terminal / Specified resistance:
No.1—Body/1MΩ, or more
No.14—Body/1MΩ, or more
16
5-5SUPPLEMENTAL RESTRAINT SYSTEM
5. Diagnostics Chart with Trouble Code

B: TROUBLE CODE 03
DIAGNOSIS:
Front sensor harness circuit is open.
Front sensor unit circuit is open.
1. Front sensor (LH and RH) inspectionIdentify faulty sensor and replace front sensor.
CAUTION:
Before performing the diagnostics on airbag system,
turn ignition switch“OFF”, disconnect battery ground
terminal and then wait at least 20 seconds.
G5M0558
1. FRONT SENSOR (LH AND RH) INSPECTION
1) Disconnect connectors (AB4) and (AB5) from airbag
control module.
2) Connect connectors (AB4) and (AB5) to test harness
B2 connector (8B).
3) Measure resistance between connector (5B) terminal.
(5B) Terminal / Specified resistance:
(RH: AB4): No. 17—No. 18 / 1.4—1.6 kΩ
(LH: AB5): No. 15—No. 16 / 1.4—1.6 kΩ
17
5-5SUPPLEMENTAL RESTRAINT SYSTEM
5. Diagnostics Chart with Trouble Code

J: TROUBLE CODE 23
DIAGNOSIS:
Airbag main harness is shorted to power supply.
Front sensor harness is shorted to power supply.
Airbag module harness (Driver or passenger) is dam-
aged.
Roll connector is shorted to power supply.
Airbag control module is faulty.
1. Front sensor inspection
O.K.
Not O.K.
Replace front sensor.
2. Airbag main harness inspection
O.K.
Not O.K.
Replace airbag main harness.
Replace airbag control module.
CAUTION:
Before performing diagnostics on airbag system, turn
ignition switch“OFF”, disconnect battery ground ter-
minal and then wait at least 20 seconds.
After 20 seconds elapse, remove instrument panel
lower cover, and disconnect (AB3) and (AB8), (AB9)
and (AB10).


27
5-5SUPPLEMENTAL RESTRAINT SYSTEM
5. Diagnostics Chart with Trouble Code

G5M0558
1. FRONT SENSOR INSPECTION
1) Disconnect connectors (AB4) and (AB5) from airbag
control module.
2) Connect connectors (AB4) and (AB5) to test harness
B2 connector (8B).
3) Measure resistance between test harness B2 connec-
tor (5B) terminal.
(5B) Terminal / Specified resistance:
(RH: AB4): No. 17—No. 18 / 1.4—1.6 kΩ
(LH: AB5): No. 15—No. 16 / 1.4—1.6 kΩ
G5M0559
2. AIRBAG MAIN HARNESS INSPECTION
1) Disconnect connector (AB6) from airbag control module
, and connect it to test harness B2
connector (8B).
2) Connect battery ground cable and turn ignition switch
“ON”(engine off).
3) Measure voltage across each test harness B2 connec-
tor (5B) terminal and body.
(5B) Terminal / Specified voltage:
No. 1—Body/1V,orless
No. 6—Body/1V,orless
No. 7—Body/1V,orless
No. 14—Body/1V,orless
28
5-5SUPPLEMENTAL RESTRAINT SYSTEM
5. Diagnostics Chart with Trouble Code

1. SELECTION OF CHECK PARTS
1) Conduct on-board diagnostic and call up trouble codes
stored in memory.
2) Select trouble code required to check airbag compo-
nent parts from those listed in table and reproduce symp-
tom.
Trouble codes Check parts Refer to 5-5:
02Front sensor (RH, LH)
Airbag main harness
Airbag module (Driver/Passenger)
Roll connector
Airbag control moduleW4A0
W5A0
W3A1—W3A2
W7A0
W6A0
03Front sensor (RH, LH)
Airbag control moduleW4A0
W6A0
04Airbag module (Passenger)
Airbag main harness
Airbag control moduleW3A2
W5A0
W6A0
11Fuse No. 8
Airbag main harness
Airbag control module
Body harnessT5D3
W5A0
W6A0
—
12Roll connector
Airbag module (Driver)
Airbag main harness
Airbag control moduleW7A0
W3A1
W5A0
W6A0
13Airbag module (Driver)
Roll connector
Airbag main harness
Airbag control moduleW3A1
W7A0
W5A0
W6A0
21Airbag control module W6A0
22Airbag module (Passenger)
Airbag main harness
Airbag control moduleW3A2
W5A0
W6A0
23Airbag main harness
Roll connector
Airbag module (Driver/Passenger)
Front sensor (RH, LH)
Airbag control moduleW5A0
W7A0
W3A1—W3A2
W4A0
W6A0
24Airbag module (Driver)
Roll connector
Airbag main harness
Airbag control moduleW3A1
W7A0
W5A0
W6A0
32Airbag module (Passenger)
Roll connector
Airbag main harness
Airbag control moduleW3A2
W7A0
W5A0
W6A0
41
5-5SUPPLEMENTAL RESTRAINT SYSTEM
5. Diagnostics Chart with Trouble Code

2. AIRBAG COMPONENT PARTS APPEARANCE
INSPECTION
Conduct appearance inspection on parts selected.
NOTE:
Also check connector terminals, wiring harness, case, etc.
for damage.
3. AIRBAG COMPONENT PARTS VIBRATION
INSPECTION
1) Gently shake check parts (to determine faults.).
2) To check airbag module or roll connector, turn and tilt
steering wheel.
CAUTION:
Do not shake or vibrate airbag control module and
front sensor at the same time as erroneous operation
may result.
G5M0461
4. SHOWERING INSPECTION TO BODY
1) Spray water on vehicle body.
CAUTION:
Do not directly spray water on airbag components.
2) Check passenger compartment for traces of leaking.
NOTE:
Also check wiring harnesses as water may leak along them
and get airbag component parts wet.
42
5-5SUPPLEMENTAL RESTRAINT SYSTEM
5. Diagnostics Chart with Trouble Code