Subaru Impreza 2003, Service Manual

Page: 2402 / 3610

ABS-62
ABS (DIAGNOSTICS)
DIAGNOSTICS PROCEDURE WITHOUT DIAGNOSTIC TROUBLE CODE (DTC)
Step Check Yes No
1 CHECK IF THE WHEELS HAVE TURNED
FREELY FOR A LONG TIME.
Check if the wheels have been turned freely for
more than 1 minute, such as when vehicle is
jacked-up, under full-lock cornering or when
tire is not in contact with road surface.
Have the wheels been turned
freely? The ABS is nor-
mal. Erase the
DTC.
NOTE:
When the wheels
turn freely for a
long time, such as
when the vehicle is
towed or jacked-
up, or when steer-
ing wheel is contin-
uously turned all
the way, this DTC
may sometimes
occur.
Go to step 2.
2 CHECK TIRE SPECIFICATIONS.
Turn the ignition switch to OFF.
Are the tire specifications cor-
rect? Go to step 3. Replace the tire.
3 CHECK WEAR OF TIRE. Is the tire worn excessively? Replace tire. Go to step 4.
4 CHECK TIRE PRESSURE. Is the tire pressure correct? Go to step 5. Adjust tire pres-
sure.
5 CHECK INSTALLATION OF ABS WHEEL
SPEED SENSOR. Are the ABS wheel speed sen-
sor installation bolts tightened
33 N·m (3.3 kgf-m, 24 ft-lb)? Go to step 6. Tighten the ABS
wheel speed sen-
sor installation
bolts securely.
6 CHECK ABS WHEEL SPEED SENSOR GAP.
Measure the tone wheel to ABS wheel speed
sensor piece gap over entire perimeter of the
wheel.
Is the gap as following value?
Front wheel:
0.3 — 0.8 mm (0.012 — 0.031
in)
Rear wheel:
0.7 — 1.2 mm (0.028 — 0.047
in) Go to step 7. Adjust the gap.
NOTE:
Adjust the gap us-
ing spacer (Part
No. 26755AA000).
If the spacer can-
not correct gap, re-
place worn sensor
or worn tone
wheel.
7 PREPARE OSCILLOSCOPE. Is an oscilloscope available? Go to step 8. Go to step 9.