Subaru Impreza 2003, Service Manual

Page: 2448 / 3610

ABS-108
ABS (DIAGNOSTICS)
DIAGNOSTICS PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step Check Yes No
1 CHECK OUTPUT OF ABS WHEEL SPEED
SENSOR USING SUBARU SELECT MONI-
TOR.
1)Select “Current data display & Save” on the
Subaru Select Monitor.
2)Read the ABS wheel speed sensor output
corresponding to faulty system in the Subaru
Select Monitor data display mode.
Does the speed indicated on
display change in response to
speedometer reading during
acceleration/deceleration
when the steering wheel is in
straight-ahead position? Go to step 2. Go to step 8.
2 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 3. Tighten the ABS
wheel speed sen-
sor installation
bolts securely.
3 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 4. Adjust the gap.
NOTE:
Adjust the gap us-
ing spacers (Part
No. 26755AA000).
If the spacers can-
not correct gap, re-
place worn sensor
or worn tone
wheel.
4 CHECK TONE WHEEL RUNOUT.
Measure the tone wheel runout.
Is the runout less than 0.05
mm (0.0020 in)? Go to step 5. Replace the tone
wheel. Front:
<Ref. to ABS-19,
Front Tone
Wheel.> Rear:
<Ref. to ABS-20,
Rear Tone
Wheel.>
5 CHECK POOR CONTACT IN CONNECTORS.
Turn the ignition switch to OFF.
Is there poor contact in con-
nectors between ABSCM&H/U
and ABS wheel speed sensor? Repair the con-
nector. Go to step 6.
6 CHECK ABSCM&H/U.
1)Connect all connectors.
2)Erase the memory.
3)Perform the inspection mode.
4)Read out the DTC.
Is the same DTC as in the cur-
rent diagnosis still being out-
put? Replace the
ABSCM&H/U.
<Ref. to ABS-7,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).> Go to step 7.
7 CHECK ANY OTHER DTC APPEARANCE. Are other DTCs being output? Proceed with the
diagnosis corre-
sponding to DTC.
A temporary poor
contact.
NOTE:
Check the harness
and connectors
between AB-
SCM&H/U and
ABS wheel speed
sensor.