sensor SUBARU LEGACY 1995 Service Repair Manual

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
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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
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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).


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

5. Control Module I/O Signal
G6M0015
ContentTerminal
No.Measuring conditions and I/O signals (ignition switch ON and engine idling)
Main power supply 2
Battery voltage is present when main power is turned ON.

“0”volt is present when main power is turned OFF.
Inhibitor switch (AT) (U.S.A.)
N position switch (AT) (CANADA)4
“0”volt is present when selector lever is set to P or N position (CANADA: N position only).

Battery voltage is present when selector lever is other than P or N position (CANADA: N
position only).
Air valve 5
“0”volt is present when vehicle is stopped.

ON-and-OFF (“0”-and-battery voltage) operation is alternately repeated while cruise control
is operating.
GND 6—
Vacuum pump motor 7
“0”volt is present when vehicle is stopped.

ON-and-OFF (“0”-and-battery voltage) operation is alternately repeated while cruise control
is operating.
Data link connector 8—
RESUME/ACCEL switch 9
Battery voltage is present when switch is turned ON.

“0”volt is present when switch is turned OFF.
SET/COAST switch 10
Battery voltage is present when switch is turned ON.

“0”volt is present when switch is turned OFF.
Ignition switch 12
Battery voltage is present when ignition switch is turned ON.

“0”volt is present when ignition switch is turned OFF.
Release valve 13
“0”volt is present when vehicle is stopped.

ON-and-OFF (“0”-and-battery voltage) operation is alternately repeated while cruise control
is operating.
Power supply to vacuum pump
motor, air valve, release valve14
“0”volt is present when vehicle is stopped.

Battery voltage is present while cruise control is operating.
Cruise main switch 15
Battery voltage is present during pressing the main switch, and then approx. 12 V is
present while switch is turned ON.

“0”volt is present when switch is turned OFF.
Brake switch 16Turn the cruise main switch to ON and leave clutch pedal released (MT).
Then check that;

“0”volt is present when brake pedal is depressed.

Battery voltage is present when brake pedal is released.
Additionally only in MT vehicle, keep the cruise main switch to ON and leave brake pedal
released.
Then check that;

“0”volt is present when clutch pedal is depressed.

Battery voltage is present when clutch pedal is released.
Data link connector 17—
Data link connector 18—
Vehicle speed sensor 2 19Lift-up the vehicle until all four wheels are raised off ground, and then rotate any wheel manu-
ally.
Approx. 5 and 0 volt pulse signals are alternately input to cruise control module.
Stop light switch 20Turn ignition switch to OFF.
Then check that;

Battery voltage is present when brake pedal is depressed.

“0”volt is present when brake pedal is released.
NOTE:
Voltage at terminals 5, 7, 13 and 14 cannot be checked unless vehicle is driving by cruise control operation.
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6-2BODY ELECTRICAL SYSTEM
5. Control Module I/O Signal

B: ON-BOARD DIAGNOSIS WITH SELECT
MONITOR
1. GENERAL
The on-board diagnosis function of the cruise control sys-
tem uses an external select monitor.
The on-board diagnosis function operates in two
categories, which are used depending on the type of prob-
lems;

Cruise cancel conditions diagnosis

Real-time diagnosis
Applicable cartridge No.: 498349601

Cruise cancel conditions diagnosis
This category of diagnosis requires actual vehicle driv-
ing in order to determine the cause, (as when cruise
speed is cancelled during driving although cruise cancel
condition is not entered).
Cruise control module memory stores the cancel condi-
tion (Code No.) which occurred during driving. When
there are plural cancel conditions (Code No.), they are
shown in order, for 2 seconds per Code No., on the
select monitor.
CAUTION:

The cruise control memory stores not only the
cruise“cancel”which occurred (although“cancel”
operation is not entered by the driver), but also the
“cancel”condition input by the driver.

The content of memory is cleared when ignition
switch or cruise main switch is turned OFF.

Real-time diagnosis
The real-time diagnosis function is used to determine
whether or not the input of output signal system is in good
order, according to signal emitted from switches, sensors,
etc.
Vehicle cannot be driven at cruise speed because prob-
lems occurs in the cruise control system or its associ-
ated circuits.
Monitor the signal conditions from switches and sen-
sors.
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6-2BODY ELECTRICAL SYSTEM
6. Diagnostics Chart for On-board Diagnosis System

8. Diagnostics Chart with Trouble Code
A: TROUBLE CODE
Trouble code Item Contents of diagnosis Page
10 OK Normal 18
11 BRAKE/ST/CL or N
Input signals from brake switch“OFF”, stop light
switch“ON”(Brake pedal is in depressed condi-
tion.)

Input signals from clutch switch“OFF”, or inhibi-
tor switch is in“N”position.
[Clutch pedal is depressed (MT), or select lever
is set to N position (AT).]20
12 NOT SET SP Out of cruise speed range 22
13 LOW SP LIM Low-speed control limiter 22
14 CANCEL SW Input signal from cancel switch 26
15 NO MEMORY No memorized cruise speed—
21 SP SENS NG Faulty vehicle speed sensor 2 22
22 COM SW NGFaulty SET/COAST switch or RESUME/ACCEL
switch26
23 RELAY NG Faulty safety relay included in cruise control module 29
24 CPU RAM NG Faulty CPU RAM included in cruise control module 29
31 MOTOR NG Faulty vacuum motor or motor drive system 30
32 AIR VAL NG Faulty air valve or valve drive system 30
33 REL VAL NG Faulty release valve or valve drive system 30
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6-2BODY ELECTRICAL SYSTEM
8. Diagnostics Chart with Trouble Code

B6M0191
D: TROUBLE CODE 12, 13 AND 21
—VEHICLE SPEED SENSOR 2 SYSTEM—
DIAGNOSIS:

Disconnection or short circuit of vehicle speed sensor 2
system.
TROUBLE SYMPTOM:

Cruise control cannot be set. (Cancelled immediately.)
1. Check operation of speedometer.
OK
Not OK
Check combination meter circuit.

2. Check input signal for cruise control module.
Not OK
OK

Check for disconnection of the cruise control
module connector terminal.

Failure of the cruise control module.
3. Perform a circuit test between combination
meter and cruise control module.
OK
Not OK
Repair or replace harness connector.
4. Check vehicle speed sensor 2.
OK
Not OK

Mechanical trouble between vehicle speed sensor
2 and speedometer shaft in transmission.

Failure of the vehicle speed sensor 2.
,Replace vehicle speed sensor 2.
Failure in combination meter circuit.




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6-2BODY ELECTRICAL SYSTEM
8. Diagnostics Chart with Trouble Code