Subaru IMPREZA GD 2007 Series Manual page 3178

asieps_tobira_IM_US.book 49 ページ ２０１２年１月１７日 火曜日 午後３時４８分
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 WHETHER A WHEEL TURNED FREELY OR
NOT.
2 CHECK TIRE SPECIFICATIONS.
Turn the ignition switch to OFF.
3 CHECK WEAR OF TIRE.
4 CHECK TIRE PRESSURE.
5 CHECK INSTALLATION OF ABS WHEEL
SPEED SENSOR.
6 CHECK ABS WHEEL SPEED SENSOR GAP.
Measure the gap between the ABS wheel
speed sensor protrusion and tone wheel.
7 PREPARE OSCILLOSCOPE.
8 CHECK ABS WHEEL SPEED SENSOR SIG-
NAL.
1) Lift up the vehicle.
2) Turn the ignition switch to OFF.
3) Connect the oscilloscope according to the
DTC.
4) Turn the ignition switch to ON.
5) Start the wheel, and measure the voltage at
the specified frequency. <Ref. to ABS(diag)-14,
WAVEFORM, Control Module I/O Signal.>
NOTE:
When this inspection is completed, ABSCM&H/
U may record DTC 29.
Connector & terminal
Front RH
(B15) No. 1 (+) — No. 2 (–):
Front LH
(B62) No. 20 (+) — No. 24 (–):
Rear RH
(B99) No. 10 (+) — No. 9 (–):
Rear LH
(B99) No. 5 (+) — No. 4 (–):
Check
Check if the wheels have been
turned freely for one minute or
more, such as when the vehicle
is jacked-up, under full-lock cor-
nering or when the wheels are
not in contact with road surface.
Are the tire specifications cor-
rect?
Is the tire worn excessively?
Is the tire pressure correct?
Is the ABS wheel speed sensor
installation bolt tightened 33
N·m (3.3 kgf-m, 24 ft-lb)?
Is the gap within the following?
Front wheel: 0.3 — 0.8 mm
(0.012 — 0.031 in), Rear
wheel: 0.7 — 1.2 mm
(0.028 — 0.047 in)
Is an oscilloscope available?
Is the oscilloscope pattern the
same waveform as shown in
the figure?
ABS(diag)-49
ABS (DIAGNOSTICS)
Yes No
ABS is normal. Go to step 2.
Erase the memory.
NOTE:
This diagnostic
trouble code may
sometimes occur if
the wheels turn
freely for a long
time, for example
when the vehicle is
towed or jacked-
up, or when steer-
ing wheel is contin-
uously turned all
the way.
Go to step 3. Replace the tire.
Replace the tire. Go to step 4.
Go to step 5.
Adjust the tire
pressure.
Go to step 6.
Tighten the ABS
wheel speed sen-
sor installation
bolts.
Go to step 7.
Adjust the gap.
NOTE:
Adjust the gap us-
ing spacers (Part
No. 26755AA000).
If spacers cannot
correct the gap, re-
place the worn
sensor or worn
tone wheel.
Go to step 8. Go to step 9.
Go to step 12. Go to step 9.