1997 SUBARU LEGACY ignition

B4M0798A
B4M0811A
7B8
CHECK VALVE RELAY.
1) Measure resistance between valve relay terminal and
terminal.
: Terminals
No. 30—No. 87:
Is resistance more than 1 MΩ?
No. 30—No. 87a:
Is resistance less than 0.5Ω?
: Go to next step.
: Replace valve relay.
2) Connect battery to valve relay terminal No. 85 and No.
86.
3) Measure resistance between valve relay terminals.
: Terminals
No. 30—No. 87:
Is resistance less than 0.5Ω?
No. 30—No. 87a:
Is resistance more than 1 MΩ?
: Go to step7B9.
: Replace valve relay.
7B9
CHECK HYDRAULIC CONTROL UNIT.
1) Turn ignition switch to OFF.
2) Connect connector (ABS1) to hydraulic control unit.
3) Turn ignition switch to ON.
: Is the ABS warning light off?
: Go to step7B10.
: Replace hydraulic control unit and check fuse No.
19.
22
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0800A
7B10
CHECK DIAGNOSIS TERMINAL.
Measure resistance between diagnosis terminals (B81)
and chassis ground.
: Terminals
Diagnosis terminal (A)—Chassis ground:
Diagnosis terminal (B)—Chassis ground:
Is the resistance less than 1Ω?
: Go to step7B11.
: Repair diagnosis terminal harness.
B4M0801A
7B11
CHECK DIAGNOSIS LINE.
1) Turn ignition switch to OFF.
2) Connect diagnosis terminal to diagnosis connector
(B82) No. 6.
3) Disconnect connector from ABSCM.
4) Measure resistance between ABSCM connector and
chassis ground.
: Connector & terminal
(F49) No. 13—Chassis ground:
Is the resistance less than 1Ω?
: Go to step7B12.
: Repair harness connector between ABSCM and
diagnosis connector.
7B12CHECK POOR CONTACT IN ABSCM
CONNECTOR.
: Is there poor contact in ABSCM connector?
: Repair connector.
: Replace ABSCM.
23
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0801A
7C2
CHECK DIAGNOSIS LINE.
1) Turn ignition switch to OFF.
2) Connect diagnosis terminal to diagnosis connector
(B82) No. 6.
3) Disconnect connector from ABSCM.
4) Measure resistance between ABSCM connector and
chassis ground.
: Connector & terminal
(F49) No. 13—Chassis ground:
Is the resistance less than 0.5Ω?
: Go to step7C3.
: Repair harness connector between ABSCM and
diagnosis connector.
7C3CHECK POOR CONTACT IN ABSCM
CONNECTOR.
: Is there poor contact in ABSCM connector?
: Repair connector.
: Replace ABSCM.
26
4-4cBRAKES [ABS 5.3 TYPE]
7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0806B
B4M1036A
8B1
CHECK RESISTANCE OF ABS SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ABS sensor.
3) Measure resistance of ABS sensor connector terminals.
: Trouble code/Connector & terminal
21/to (B6) No. 1—No. 2
23/to (B15) No. 1—No. 2
25/to (P8) No. 1—No. 2
27/to (P9) No. 1—No. 2
Is resistance 0.8—1.2 kΩ?
: Go to step8B2.
: Replace ABS sensor.
B4M0807B
B4M1037A
8B2CHECK BATTERY SHORT OF ABS SEN-
SOR.
1) Disconnect connector from ABSCM.
2) Turn ignition switch to ON.
3) Measure voltage between ABS sensor and chassis
ground.
: Trouble code/Connector & terminal
21/to (B6) No. 1 (+)—Chassis ground ()
23/to (B15) No. 1 (+)—Chassis ground ()
25/to (P8) No. 1 (+)—Chassis ground ()
27/to (P9) No. 1 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Replace ABS sensor.
4) Turn ignition switch to OFF.
5) Measure voltage between ABS sensor and chassis
ground.
: Trouble code/Connector & terminal
21/to (B6) No. 1 (+)—Chassis ground ()
23/to (B15) No. 1 (+)—Chassis ground ()
25/to (P8) No. 1 (+)—Chassis ground ()
27/to (P9) No. 1 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8B3.
: Replace ABS sensor.
30
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0809A
8B3CHECK HARNESS CONNECTOR
BETWEEN ABSCM AND ABS SENSOR.
1) Connect connector to ABS sensor.
2) Measure resistance between ABSCM connector termi-
nals.
: Trouble code/Connector & terminal
21/(F49) No. 14—No. 15
23/(F49) No. 49—No. 19
25/(F49) No. 18—No. 46
27/(F49) No. 16—No. 17
Is resistance 0.8—1.2 kΩ?
: Go to step8B4.
: Repair harness connector between ABSCM and
ABS sensor.
B4M0810A
8B4
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
21/(F49) No. 14 (+)—Chassis ground ()
23/(F49) No. 49 (+)—Chassis ground ()
25/(F49) No. 18 (+)—Chassis ground ()
27/(F49) No. 16 (+)—Chassis ground ()
Is voltage 0 V?
: Go to next step.
: Repair harness between ABSCM and ABS sen-
sor.
3) Turn ignition switch to OFF.
4) Measure voltage between ABSCM connector and chas-
sis ground.
: Trouble code/Connector & terminal
21/(F49) No. 14 (+)—Chassis ground ()
23/(F49) No. 49 (+)—Chassis ground ()
25/(F49) No. 18 (+)—Chassis ground ()
27/(F49) No. 16 (+)—Chassis ground ()
Is voltage 0 V?
: Go to step8B5.
: Repair harness between ABSCM and ABS sen-
sor.
31
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

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)
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 13).
B4M0815A
2) Raise all four wheels of ground.
3) Turn ignition switch OFF.
4) Disconnect connector from ABS control module.
5) Remove band.
6) Remove cable clamp cover.
7) Remove screws securing connector cover.
CAUTION:
Do not allow harness to catch on adjacent parts dur-
ing installation.
B4M1026
8) Remove connector cover.
B4M1027A
NOTE:

To install, reverse above removal procedures.

Align connector cover rib with connector hole before
installation.
36
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

9) Connect connector to ABS control module.
10) Connect the oscilloscope to the ABS control module
connector in accordance with trouble code.
11) Turn ignition switch ON.
B4M0816A
12) 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:
22 / (F49) No. 14 (+)—No. 15 ()
24 / (F49) No. 49 (+)—No. 19 ()
26 / (F49) No. 18 (+)—No. 46 ()
28 / (F49) No. 16 (+)—No. 17 ()
Specified voltage: 0.12—1 V (When it is 20 Hz.)
: Is oscilloscope pattern smooth, as shown in
figure?
: Go to step8C2.
: Go to next step.
13) Remove disc rotor from hub in accordance with trouble
code.
: 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.
14) Measure hub runout.
: Is the runout less than 0.05 mm (0.0020 in)?
: Go to step8C2.
: Repair hub.
37
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code

B4M0806B
B4M1036A
8C2
CHECK RESISTANCE OF ABS SENSOR.
1) Turn ignition switch OFF.
2) Disconnect connector from ABS sensor.
3) Measure resistance between ABS sensor connector ter-
minals.
: Trouble code/Connector & terminal
22/to (B6) No. 1—No. 2
24/to (B15) No. 1—No. 2
26/to (P8) No. 1—No. 2
28/to (P9) No. 1—No. 2
Is resistance 0.8—1.2 kΩ?
: Go to step8C3.
: Replace ABS sensor.
B4M0818B
B4M1042A
8C3CHECK GROUND SHORT OF ABS SEN-
SOR.
Measure resistance between ABS sensor and chassis
ground.
: Trouble code/Connector & terminal
22/to (B6) No. 1—Chassis ground
24/to (B15) No. 1—Chassis ground
26/to (P8) No. 1—Chassis ground
28/to (P9) No. 1—Chassis ground
Is resistance more than 1 MΩ?
: Go to step8C4.
: Replace ABS sensor.
38
4-4cBRAKES [ABS 5.3 TYPE]
8. Diagnostics Chart with Trouble Code