Page 364 of 801

YH4
GRAND
VITARA
ANTILOCK BRAKE SYSTEM (ABS) (OPTIONAL) 5E1-23
1. Ignition switch
2. ABS hydraulic unit /
control module assembly
3. Left-front wheel speed
sensor
4. Right-front wheel speed
sensor
5. Left-rear wheel speed
sensor
6. Right-rear wheel speed
sensor
7. ABS hydraulic unit /
control connector of harness
DTC 21 (DTC C1021), 22 (DTC C1022) ± RIGHT-FRONT WHEEL SPEED SENSOR
CIRCUIT
DTC 25 (DTC C1025), 26 (DTC C1026) ± LEFT-FRONT WHEEL SPEED SENSOR
CIRCUIT
DTC 31 (DTC C1031), 32 (DTC C1032) ± RIGHT-REAR WHEEL SPEED SENSOR
CIRCUIT
DTC 35 (DTC C1035), 36 (DTC C1036) ± LEFT-REAR WHEEL SPEED SENSOR
CIRCUIT
DESCRIPTION
The ABS control module monitors the voltage at the positive (+) terminal of each sensor while the ignition switch
is ON. When the voltage is not within the specified range, an applicable DTC will be set. Also, when no sensor signal
is inputted at starting or while running, an applicable DTC will be set.
NOTE:
When the vehicle was operated in any of the following ways, one of these DTC's may be set even when
the sensor is in good condition. If such possibility is suspected, repair the trouble (dragging of brake, etc.)
of the vehicle, clear DTC once and then after performing the driving test as described in Step 2 of ªABS
DIAG. FLOW TABLEº, check whether or not any abnormality exists.
± The vehicle was driven with parking brake pulled.
± The vehicle was driven with brake dragging.
± Wheel spin occurred while driving.
± Wheel(s) was turned while the vehicle was jacked up.
± The vehicle was stuck.
Page 365 of 801

YH4
GRAND
VITARA
5E1-24 ANTILOCK BRAKE SYSTEM (ABS) (OPTIONAL)
INSPECTION
STEPACTIONYESNO
11) Disconnect the applicable sensor connector with
ignition switch OFF.
2) Measure resistance between sensor terminals.
Resistance of wheel speed sensor:
1.2 ± 1.6 k (at 20C, 68F)
3) Measure resistance between each terminal and
body ground.
Insulation resistance: 1M or higher
Were measured resistance values in step 2) and 3)
as specified? (See Fig. 1)Go to step 2.Replace sensor.
21) Ignition switch OFF.
2) Disconnect connector from ABS hydraulic
unit / control module assembly. (See Fig. 2)
3) Check for proper connection to ABS hydraulic unit /
control module assembly at each sensor terminal.
4) If OK then, turn ignition switch ON and measure
voltage between sensor positive terminal of module
connector and body ground.
Is it 0 V?Go to step 3.Sensor positive
circuit shorted to
power.
31) Ignition switch OFF.
2) Connect connector to sensor.
3) Measure resistance between sensor terminals at
module connector.
4) Measure resistance between sensor positive
terminal and negative terminal of module connector,
between positive terminal and body ground.
Are measured resistance values within each specified
range described in above step 1?Go to step 4.Circuit open or
shorted to
ground.
41) Remove wheel speed sensor.
2) Check sensor for damage or foreign material being
attached.
Is it in good condition? (See Fig. 3)Go to step 5.Clean or replace
sensor.
5Check visually through wheel speed sensor
installation hole for following.
Rotor neither missing or damaged.
No foreign material being attached.
Rotor not being eccentric.
Wheel bearing free from excessive play.
Are they in good condition? (See Fig. 4)Go to step 6.Clean, repair or
replace.
61) Install sensor to knuckle or axle housing.
2) Tighten sensor bolt to specified torque and check
that there is not any clearance between sensor and
knuckle or axle housing. (See Fig. 5)
Replace sensor if any.
Referring to item OUTPUT VOLTAGE INSPECTION of
FRONT WHEEL SPEED SENSOR, check output voltage
or waveform of sensor. Is proper output voltage or
waveform obtained?Substitute a
known-good ABS
hydraulic unit /
control module
assembly and
recheck.Replace sensor
and recheck.
Page 375 of 801
YH4
GRAND
VITARA
5E1-34 ANTILOCK BRAKE SYSTEM (ABS) (OPTIONAL)
1. Left front wheel speed sensor
2. Left front strut
3. Sensor rotor
1. Wheel speed sensor connector
1. Peak-to-peak voltage
FRONT WHEEL SPEED SENSOR
OUTPUT VOLTAGE INSPECTION
1) Turn ignition switch OFF.
2) Hoist vehicle a little.
3) Disconnect connector of wheel speed sensor.
4) Connect voltmeter between connector terminals.
5) While turning wheel at a speed of approximately 2 / 3 to 1 full
rotation per second, check AC voltage of sensor.
Output AC voltage at 2 / 3 to
one rotation per second (35 ± 53 Hz): 106 mV or more
If measured voltage is not as specified, check sensor, rotor and
their installation conditions.
Reference
When using oscilloscope for this check, check if peak-to-peak volt-
age meets specification and waveform is complete.
Peak-to-peak voltage
at 2 / 3 to one rotation per second (35 ± 53 Hz): 150 mV or more
Page 376 of 801

YH4
GRAND
VITARA
ANTILOCK BRAKE SYSTEM (ABS) (OPTIONAL) 5E1-35
FORWARD
1. Front wheel speed
sensor connector
2. Headlight assembly
1. Front wheel speed sensor
2. Bolt
REMOVAL
1) Disconnect negative cable at battery.
2) Hoist vehicle and remove wheel.
3) Disconnect front wheel speed sensor connector.
4) Remove harness clamp bolts and remove front wheel speed
sensor from knuckle.
CAUTION:
Do not pull wire harness when removing front wheel
speed sensor.
Do not cause damage to surface of front wheel speed
sensor and do not allow dust, etc. to enter its installa-
tion hole.
SENSOR INSPECTION
Check sensor for damage.
Check sensor for resistance.
Resistance between terminals: 1.2 ± 1.6 k at 20C (68F)
Resistance between terminal and sensor body: 1 M or more
If any faulty is found, replace.
SENSOR ROTOR INSPECTION
Check rotor for being missing, damaged or deformed.
Turn drive shaft and check if rotor rotation is free from eccentricity
and looseness.
Check that no foreign material is attached.
If any faulty is found, repair or replace. Refer to WHEEL HUB RE-
MOVAL and INSTALLATION in Section 3D.
Page 377 of 801
YH4
GRAND
VITARA
5E1-36 ANTILOCK BRAKE SYSTEM (ABS) (OPTIONAL)
1. Front wheel speed sensor
2. Bolt
INSTALLATION
1) Check that no foreign material is attached to sensor and rotor.
2) Install it by reversing removal procedure.
CAUTION:
Do not pull wire harness or twist more than necessary
when installing front wheel speed sensor.
Fit harness grommet to inner fender securely.
Tightening Torque
(a): 10 N
.m (1.0 kg-m, 7.5 lb-ft)
(b): 23 N
.m (2.3 kg-m, 17.0 lb-ft)
3) Check that there is no clearance between sensor and knuckle.
FRONT SENSOR ROTOR
REMOVAL
Remove front sensor rotor referring to WHEEL HUB REMOVAL in
Section 3D.
INSTALLATION
CAUTION:
Don't reuse front sensor rotor removed from front wheel
hub because of it for being deformed.
Install new front sensor rotor referring to WHEEL HUB INSTALLA-
TION in Section 3D.
Page 378 of 801
YH4
GRAND
VITARA
ANTILOCK BRAKE SYSTEM (ABS) (OPTIONAL) 5E1-37
1. Rear wheel speed sensor
2. Sensor rotor
3. Rear axle housing
1. Rear wheel speed
sensor harness
2. Connector
1. Sensor bolt
2. Clamps
REAR WHEEL SPEED SENSOR
OUTPUT VOLTAGE INSPECTION
Check in the same procedure as that used of front wheel speed
sensor check.
Output AC voltage at 2 / 3 to
one rotation per second (25 ± 38 Hz): 106 mV or more
Reference
When using oscilloscope,
peak-to-peak voltage at 2 / 3 to
one rotation per second (25 ± 38 Hz): 150 mV or more
REMOVAL
1) Disconnect negative cable at battery.
2) Hoist vehicle.
3) Disconnect rear wheel speed sensor connector and detach wire
harness from vehicle body and rear axle.
4) Remove harness clamps and remove rear wheel speed sensor
from rear axle.
CAUTION:
Do not pull wire harness when removing rear wheel
speed sensor.
Do not cause damage to surface of rear wheel speed
sensor and do not allow dust, etc. to enter its installa-
tion hole.
Page 379 of 801
YH4
GRAND
VITARA
5E1-38 ANTILOCK BRAKE SYSTEM (ABS) (OPTIONAL)
1. Clamps
2. Sensor bolt
SENSOR INSPECTION
Check sensor (pole piece) for damage or bent.
Check sensor for resistance.
Resistance between
terminals : 1.2 ± 1.6 k at 20C, 68F
Resistance between
terminal and sensor body: 1 M or more
If any faulty is found, replace.
SENSOR ROTOR INSPECTION
Check rotor serration (teeth) for being missing, damaged or de-
formed.
Turn wheel and check if rotor rotation is free from eccentricity and
looseness.
Check that no foreign material is attached.
If any faulty is found, repair or replace.
INSTALLATION
1) Check that no foreign material is attached to sensor and rotor.
2) Install it by reversing removal procedure.
Tightening Torque
(a): 21 N
.m (2.1 kg-m, 15.0 lb-ft)
CAUTION:
Do not pull wire harness or twist more than necessary
when installing rear wheel speed sensor.
3) Check that there is no clearance between sensor and knuckle.
Page 382 of 801
YH4
GRAND
VITARA
ANTILOCK BRAKE SYSTEM (ABS) (OPTIONAL) 5E1-41
(d)
TRANSFER 4WD SWITCH
For removal, inspection and installation of this switch, refer to
SWITCHES in Section 7A.
TIGHTENING TORQUE SPECIFICATIONS
FasteningpartsTightening torqueFastening artsN.mkg-mlb-ft
Brake pipe flare nut: (a)161.611.5
ABS hydraulic unit nut: (b)212.115.5
ABS hydraulic unit bracket bolt: (c)101.07.5
Wheel speed sensor bolt(Front): (d)232.317.0Wheel s eed sensor bolt(Rear): (e)212.115.5
Parking lever assy mounting bolt: (f)232.317.0