Page 753 of 2453

BR-39
Brake Vacuum Pump
BRAKE
16.Brake Vacuum Pump
A: REMOVAL
1. BRAKE VACUUM PUMP
1) Disconnect the ground cable from the battery.
2) Disconnect the brake vacuum pump connector.
3) Remove the vacuum hose.
4) Remove the bolt, and remove the brake vacuum
pump.
2. VACUUM HOSE
Remove the clip and remove the vacuum hose.
B: INSTALLATION
1. BRAKE VACUUM PUMP
Install in the reverse order of removal.
Tightening torque:
7.5 N·m (0.76 kgf-m, 5.5 ft-lb)
2. VACUUM HOSE
Install in the reverse order of removal.
CAUTION:
The vacuum hose has an installation direction.
Make sure to install in the proper direction.
C: INSPECTION
1. BRAKE VACUUM PUMP
Inspect for whether or not the pump operates when
battery voltage is applied to the connector terminal.
2. VACUUM HOSE
Check to see that air only flows in one direction,
when air is blown into or sucked from the hose.
(1) To engine
(2) Vacuum hose
(3) Vacuum pipe
(4) Marking (Marking to vacuum pipe side)
BR-00506
BR-00507
(1)
(2)(2)
(4)
(3)
ENG
Page 754 of 2453
BR-40
Brake Vacuum Sensor
BRAKE
17.Brake Vacuum Sensor
A: REMOVAL
1) Disconnect the ground cable from the battery.
2) Disconnect the brake vacuum sensor connector.
3) Remove the vacuum hose from the brake vacu-
um sensor.
4) Remove the bolt, and remove the brake vacuum
sensor.
B: INSTALLATION
Install in the reverse order of removal.
Tightening torque:
7.5 N·m (0.76 kgf-m, 5.5 ft-lb)
BR-00509
Page 760 of 2453

BVC(diag)-5
General Description
BRAKE VACUUM CONTROL (BVC) (DIAGNOSTICS)
3. General Description
A: CAUTION
1. SRS AIRBAG SYSTEM
Airbag system wiring harness is routed near the ABS wheel speed sensor and VDCCM&H/U.
CAUTION:
•All airbag system wiring harness and connectors are colored yellow. Do not use the electrical test
equipment on these circuits.
•Be careful not to damage the airbag system wiring harness.
B: INSPECTION
Before performing diagnosis, check the following items which might affect the brake vacuum control.
1. BATTERY
Measure the battery voltage and check electrolyte.
Standard voltage: 12 V or more
Specific gravity: 1.260 or more
2. BRAKE VACUUM HOSE
Make sure the brake vacuum hose is not cracked or loose.
C: PREPARATION TOOL
1. SPECIAL TOOL
2. GENERAL TOOL
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
18482AA010 CARTRIDGE Troubleshooting for the electrical system.
22771AA030 SUBARU SELECT
MONITOR KIT
Tr o u b l e s h o o t i n g f o r t h e e l e c t r i c a l s y s t e m .
TOOL NAME REMARKS
Circuit tester Used for measuring resistance, voltage and current.
Oscilloscope Used for measuring the sensor.
ST18482AA010
ST22771AA030
Page 770 of 2453
BVC(diag)-15
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BRAKE VACUUM CONTROL (BVC) (DIAGNOSTICS)
11.Diagnostic Procedure with Diagnostic Trouble Code (DTC)
A: DTC 11 SENSOR OUTPUT OUT OF RANGE
DTC DETECTING CONDITION:
Brake vacuum sensor malfunction
TROUBLE SYMPTOM:
Brake vacuum pump does not operate.
WIRING DIAGRAM:
BR-00528
2
1
B25B
B422
1234
B432
2
1
4
36
5
8
7
B432
SBF HOLDER
3
7
14
21
53
43
VC2
VC3
B422
B422
VC3
RELAY BOX(VACUUMPUMP RELAY)
B417
VAC U U MPUMP
26
41
B47
MAINRELAY
B411
VAC U U M S E N S O RECM
A: B134B: B135C: B136
C23B30B22A27C8312
JOINT CONNECTOR
B424
**
B417B411
213
B: C:B135
5672134
29
101112131415252416
30
98171819202821222332312627333435
B136
16101112131415252430
9871718192028212223293231
123456
2726333435
VC2
A:B134
85610 11 12 13 14 157213416
3019 20 2228 29
91718252123 24323126 2733 34
B424
34561278
(BROWN)
21
5436
B47
* : TERMINAL NO. OPTIONAL ARRANGEMENT
21
SBF-7BATTERY
30A
3412
5
8967
10131211
14
Page 771 of 2453

BVC(diag)-16
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BRAKE VACUUM CONTROL (BVC) (DIAGNOSTICS)
Step Check Yes No
1CHECK BRAKE VACUUM SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the brake vacuum sensor con-
nector.
3) Remove the brake vacuum sensor.
BR-40, REMOVAL, Brake Vacuum Sensor.>
4) Measure the resistance between brake
vacuum sensor connector terminals.
Te r m i n a l s
No. 1 — No. 3:
No. 2 — No. 3:
Is the resistance 15 kΩ or
less?
Go to step 2.Replace the brake
vacuum sensor.
Brake Vacuum
Sensor.>
2CHECK HARNESS BETWEEN ECM AND
BRAKE VACUUM SENSOR CONNECTOR.
1) Disconnect the connectors from ECM.
2) Measure the resistance of the harness
between ECM and the brake vacuum sensor
connector.
Connector & terminal
(B135) No. 30 — (B411) No. 1:
(B135) No. 22 — (B411) No. 3:
(B134) No. 27 — (B411) No. 2:
Is the resistance less than 1
Ω?
Go to step 3.Repair the open
circuit of harness
between ECM and
brake vacuum
sensor connector.
3CHECK HARNESS BETWEEN ECM AND
BRAKE VACUUM SENSOR CONNECTOR.
Measure the resistance of harness between
ECM and chassis ground.
Connector & terminal
(B135) No. 30 — Chassis ground:
(B135) No. 22 — Chassis ground:
(B134) No. 27 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 4.Repair the ground
short of the har-
ness between
ECM and brake
vacuum sensor
connector.
4CHECK HARNESS BETWEEN ECM AND
BRAKE VACUUM SENSOR CONNECTOR.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 30 (+) — Chassis ground (–):
(B135) No. 22 (+) — Chassis ground (–):
(B134) No. 27 (+) — Chassis ground (–):
Is the voltage less than 0.5 V? Go to step 5.Repair the battery
short circuit
between ECM and
brake vacuum
sensor connector.
5CHECK THE BRAKE VACUUM SENSOR
POWER SUPPLY.
1) Connect the connectors to ECM and brake
vacuum sensor.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM con-
nector terminals.
Connector & terminal
(B135) No. 22 (+) — (B135) No. 30 (–):
Is the voltage 4.75 — 5.25 V? Go to step 6.Replace the ECM.
FU(H6DO)-32,
Engine Control
Module (ECM).>
6CHECK CURRENT DATA.
1) Turn the ignition switch to ON.
2) Depress the brake pedal several times, until
the pedal becomes firm.
3) Read the current data of the brake negative
pressure pump system using the Subaru
Select Monitor.
Select Monitor.>
Is the atmospheric pressure —
brake booster pressure
between –8 — +8 mmHg?
Te m p o r a r y p o o r
contact occurs.
Replace the ECM.
FU(H6DO)-32,
Engine Control
Module (ECM).>
Page 772 of 2453
BVC(diag)-17
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BRAKE VACUUM CONTROL (BVC) (DIAGNOSTICS)
B: DTC 12 COMPARE ERROR IN OTHER SENSOR
DTC DETECTING CONDITION:
Brake vacuum sensor malfunction
TROUBLE SYMPTOM:
Brake vacuum pump does not operate.
WIRING DIAGRAM:
BR-00528
2
1
B25B
B422
1234
B432
2
1
4
36
5
8
7
B432
SBF HOLDER
3
7
14
21
53
43
VC2
VC3
B422
B422
VC3
RELAY BOX(VACUUMPUMP RELAY)
B417
VAC U U MPUMP
26
41
B47
MAINRELAY
B411
VAC U U M S E N S O RECM
A: B134B: B135C: B136
C23B30B22A27C8312
JOINT CONNECTOR
B424
**
B417B411
213
B: C:B135
5672134
29
101112131415252416
30
98171819202821222332312627333435
B136
16101112131415252430
9871718192028212223293231
123456
2726333435
VC2
A:B134
85610 11 12 13 14 157213416
3019 20 2228 29
91718252123 24323126 2733 34
B424
34561278
(BROWN)
21
5436
B47
* : TERMINAL NO. OPTIONAL ARRANGEMENT
21
SBF-7BATTERY
30A
3412
5
8967
10131211
14
Page 773 of 2453

BVC(diag)-18
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BRAKE VACUUM CONTROL (BVC) (DIAGNOSTICS)
Step Check Yes No
1CHECK BRAKE VACUUM HOSE.
1) Turn the ignition switch to OFF.
2) Check that status of the brake vacuum
hose connection.
Is the brake vacuum hose con-
nected firmly?
Go to step 2.Connect the brake
vacuum hose.
2CHECK BRAKE VACUUM HOSE.
1) Turn the ignition switch to ON and start
engine.
2) Check for leakage from the brake vacuum
hose.
Is there a leak from the brake
vacuum hose?
Replace the brake
vacuum hose.
Go to step 3.
3CHECK BRAKE VACUUM SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the brake vacuum sensor con-
nector.
3) Remove the brake vacuum sensor.
BR-40, REMOVAL, Brake Vacuum Sensor.>
4) Measure the resistance between brake
vacuum sensor connector terminals.
Te r m i n a l s
No. 1 — No. 3:
No. 2 — No. 3:
Is the resistance 15 kΩ or
less?
Go to step 4.Replace the brake
vacuum sensor.
Brake Vacuum
Sensor.>
4CHECK HARNESS BETWEEN ECM AND
BRAKE VACUUM SENSOR CONNECTOR.
1) Disconnect the connectors from ECM.
2) Measure the resistance of the harness
between ECM and the brake vacuum sensor
connector.
Connector & terminal
(B135) No. 30 — (B411) No. 1:
(B135) No. 22 — (B411) No. 3:
(B134) No. 27 — (B411) No. 2:
Is the resistance less than 1
Ω?
Go to step 5.Repair the open
circuit of harness
between ECM and
brake vacuum
sensor connector.
5CHECK HARNESS BETWEEN ECM AND
BRAKE VACUUM SENSOR CONNECTOR.
Measure the resistance of harness between
ECM and chassis ground.
Connector & terminal
(B135) No. 30 — Chassis ground:
(B135) No. 22 — Chassis ground:
(B134) No. 27 — Chassis ground:
Is the resistance more than 1
MΩ?
Go to step 6.Repair the ground
short circuit
between ECM and
brake vacuum
sensor connector.
6CHECK HARNESS BETWEEN ECM AND
BRAKE VACUUM SENSOR CONNECTOR.
Measure the voltage between ECM and chas-
sis ground.
Connector & terminal
(B135) No. 30 (+) — Chassis ground (–):
(B135) No. 22 (+) — Chassis ground (–):
(B134) No. 27 (+) — Chassis ground (–):
Is the voltage less than 0.5 V? Go to step 7.Repair the battery
short of the har-
ness between
ECM and brake
vacuum sensor
connector.
7CHECK THE BRAKE VACUUM SENSOR
POWER SUPPLY.
1) Connect the connectors to ECM and brake
vacuum sensor.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM con-
nector terminals.
Connector & terminal
(B135) No. 22 (+) — (B135) No. 30 (–):
Is the voltage 4.75 — 5.25 V? Go to step 8.Replace the ECM.
FU(H6DO)-32,
Engine Control
Module (ECM).>
Page 775 of 2453
BVC(diag)-20
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BRAKE VACUUM CONTROL (BVC) (DIAGNOSTICS)
C: DTC 13 PRESSURE SENSOR OUTPUT
DTC DETECTING CONDITION:
Brake vacuum sensor malfunction
TROUBLE SYMPTOM:
Brake vacuum pump does not operate.
WIRING DIAGRAM:
BR-00528
2
1
B25B
B422
1234
B432
2
1
4
36
5
8
7
B432
SBF HOLDER
3
7
14
21
53
43
VC2
VC3
B422
B422
VC3
RELAY BOX(VACUUMPUMP RELAY)
B417
VAC U U MPUMP
26
41
B47
MAINRELAY
B411
VAC U U M S E N S O RECM
A: B134B: B135C: B136
C23B30B22A27C8312
JOINT CONNECTOR
B424
**
B417B411
213
B: C:B135
5672134
29
101112131415252416
30
98171819202821222332312627333435
B136
16101112131415252430
9871718192028212223293231
123456
2726333435
VC2
A:B134
85610 11 12 13 14 157213416
3019 20 2228 29
91718252123 24323126 2733 34
B424
34561278
(BROWN)
21
5436
B47
* : TERMINAL NO. OPTIONAL ARRANGEMENT
21
SBF-7BATTERY
30A
3412
5
8967
10131211
14