SUBARU LEGACY 1996 Service Repair Manual

B4M1038A
8C9
CHECK SHIELD CIRCUIT.
1) Connect all connectors.
2) Measure resistance between shield connector and
chassis ground.
: Trouble code/Connector & terminal
22/(B100) No. 11—Chassis ground
24/(B100) No. 2—Chassis ground
26/(P1) No. 8—Chassis ground
28/(P1) No. 3—Chassis ground
Is resistance less than 0.5Ω?
: Go to step8C10.
: Repair shield harness.
8C10
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 noise interference.
41
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

D: TROUBLE CODE 29
—ABNORMAL ABS SENSOR SIGNAL (ANY
ONE OF FOUR)—
DIAGNOSIS:

Faulty ABS sensor signal (noise, irregular signal, etc.)

Faulty tone wheel

Wheels turning freely for a long time
TROUBLE SYMPTOM:

ABS does not operate.
8D1.Check if the wheels have turned freely for a
long time.
8D2.Check tire.
8D3.Check ABS sensor mechanical trouble.
8D4.Check ABSCM.



42
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

WIRING DIAGRAM:
B4M1035
8D1CHECK IF THE WHEELS HAVE TURNED
FREELY FOR A LONG TIME.
: Check if the wheels have been turned freely
for more than one minute, such as when the
vehicle is jacked-up, under full-lock corner-
ing or when tire is not in contact with road
surface.
: The ABS is normal. Erase the trouble code.
NOTE:
When the wheels turn freely for a long time, such as when
the vehicle is towed or jacked-up, or when steering wheel
is continuously turned all the way, this trouble code may
sometimes occur.
: Go to step8D2.
43
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

8D2
CHECK TIRE.
: Are the tire specifications correct?
: Go to next.
: Replace tire.
: Is the tire worn excessively?
: Replace tire.
: Go to next.
: Is the tire pressure correct?
: Go to step8D3.
: Adjust tire pressure.
8D3CHECK ABS SENSOR MECHANICAL
TROUBLE.
: Tightening torque:
32±10 N⋅m (3.3±1.0 kg-m, 24±7 ft-lb)
Are the ABS sensor installation bolts tight-
ened securely?
: Go to next.
: Tighten ABS sensor installation bolts securely.
: Tightening torque:
13±3 N⋅m (1.3±0.3 kg-m, 9±2.2 ft-lb)
Are the tone wheel installation bolts tight-
ened securely?
: Go to next step.
: Tighten tone wheel installation bolts securely.
G4M0700
1) Measure tone wheel to pole piece gap over entire
perimeter of the wheel.
: Is the gap within the specifications shown
in the following table?
SpecificationsFront wheel Rear wheel
0.9—1.4 mm
(0.035—0.055 in)0.7—1.2 mm
(0.028—0.047 in)
44
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

G4M0701
: Go to next.
: Adjust the gap.
NOTE:
Adjust the gap using spacer (Part No. 26755AA000). If
spacers cannot correct the gap, replace worn sensor or
worn tone wheel.
: Is an oscilloscope available?
: Go to next step.
: Go to step 10).
2) Raise all four wheels of ground.
3) Turn ignition switch OFF.
4) Disconnect connector from ABS control module.
5) Disconnect connector cover from connector.

6) Connect connector to ABS control module.
7) Connect the oscilloscope to the ABS control module
connector.
8) Turn ignition switch ON.
B4M0816A
9) Rotate wheels and measure voltage at specified fre-
quency.
NOTE:
When this inspection is completed, the ABS control mod-
ule sometimes stores the trouble code 29.
TROUBLE CODE / Connector & terminal:
(F49) No. 14 (+)—No. 15 () (Front RH)
(F49) No. 49 (+)—No. 19 () (Front LH)
(F49) No. 18 (+)—No. 46 () (Rear RH)
(F49) No. 16 (+)—No. 17 () (Rear LH)
Specified voltage: 0.12—1 V (When it is 20 Hz.)
: Is oscilloscope pattern smooth, as shown in
figure?
: Go to step8D4.
: Go to next step.
45
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

10) Remove disc rotor from hub.
: Is the ABS sensor pole piece or the tone
wheel contaminated by dirt or other foreign
matter?
: Thoroughly remove dirt or other foreign matter.
: Go to next.
: Are there broken or damaged teeth in the
ABS sensor pole piece or the tone wheel?
: Replace ABS sensor or tone wheel.
: Go to next step.
11) Measure hub runout.
: Is the runout less than 0.05 mm (0.0020 in)?
: Go to step8D4.
: Repair hub.
8D4
CHECK ABSCM.
1) Turn ignition switch to OFF.
2) Connect all connectors.
3) Erase the memory.
4) Perform inspection mode.
5) 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.
46
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

E: TROUBLE CODE 31 (FRONT RH)
TROUBLE CODE 33 (FRONT LH)
TROUBLE CODE 35 (REAR RH)
TROUBLE CODE 37 (REAR LH)
—ABNORMAL INLET SOLENOID VALVE
CIRCUIT(S) IN HYDRAULIC UNIT—
DIAGNOSIS:

Faulty harness/connector

Faulty inlet solenoid valve in hydraulic unit
TROUBLE SYMPTOM:

ABS does not operate.
8E1.Check resistance of solenoid valve.
8E2.Check ground short of solenoid valve.
8E3.Check battery short of solenoid valve.
8E4.Check battery short of harness.
8E5.Check ground short of harness.
8E6.Check harness connector between ABSCM
and hydraulic unit.
8E7.Check poor contact in connector between
ABSCM and hydraulic unit.
8E8.Check ABSCM.







47
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

WIRING DIAGRAM:
B4M1046
48
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0824B
8E1CHECK RESISTANCE OF SOLENOID
VA LV E .
1) Turn ignition switch to OFF.
2) Disconnect two connectors (ABS1, F9) from hydraulic
unit.
3) Measure resistance between hydraulic unit connector
terminals.
: Trouble code/Connector & terminal
31/to (F9) No. 4—to (ABS1) No. 2
33/to (F9) No. 1—to (ABS1) No. 2
35/to (F9) No. 2—to (ABS1) No. 2
37/to (F9) No. 3—to (ABS1) No. 2
Is resistance 8.5±0.7Ω?
: Go to step8E2.
: Replace hydraulic unit.
B4M0825B
8E2CHECK GROUND SHORT OF SOLENOID
VA LV E .
Measure resistance between hydraulic unit connector and
chassis ground.
: Trouble code/Connector & terminal
31/to (F9) No. 4—Chassis ground
33/to (F9) No. 1—Chassis ground
35/to (F9) No. 2—Chassis ground
37/to (F9) No. 3—Chassis ground
Is resistance more than 1 MΩ?
: Go to step8E3.
: Replace hydraulic unit.
49
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0826B
8E3CHECK BATTERY SHORT OF SOLENOID
VA LV E .
1) Disconnect connector from ABSCM.
2) Turn ignition switch to ON.
3) Measure voltage between hydraulic unit connector and
chassis ground.
: Trouble code/Connector & terminal
31/to (F9) No. 4 (+)—Chassis ground ()
33/to (F9) No. 1 (+)—Chassis ground ()
35/to (F9) No. 2 (+)—Chassis ground ()
37/to (F9) No. 3 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Replace hydraulic unit.
4) Turn ignition switch to OFF.
5) Measure voltage between hydraulic unit connector and
chassis ground.
: Trouble code/Connector & terminal
31/to (F9) No. 4 (+)—Chassis ground ()
33/to (F9) No. 1 (+)—Chassis ground ()
35/to (F9) No. 2 (+)—Chassis ground ()
37/to (F9) No. 3 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8E4.
: Replace hydraulic unit.
B4M0827A
8E4
CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM connector and chas-
sis ground.
: Trouble code/Connector & terminal
31/(F49) No. 30 (+)—Chassis ground ()
33/(F49) No. 24 (+)—Chassis ground ()
35/(F49) No. 23 (+)—Chassis ground ()
37/(F49) No. 31 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Repair harness between ABSCM and hydraulic
unit.
50
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code