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Downloaded from www.Manualslib.com manuals search engine ANTILOCK BRAKE SYSTEM (ABS) 5E-19
INSPECTION
Step Action Yes No
1 Is G sensor installed floor securely? Go to step 2. Tighten sensor or bracket
screw securely. If not, use
new screw.
2 1) Ignition switch OFF.
2) Remove G sensor with bracket.
3) Check for proper connection to G sensor.
4) If OK, then check G sensor referring to “G
Sensor” in this section.
Is it in good condition?Go to step 3. Replace G sensor.
3 1) Disconnect connectors from ABS hydraulic
unit / control module assembly (See [A])
and G sensor.
2) Check for proper connection to ABS control
module at terminals “A11” and “A13”.
3) If OK, then turn ignition switch ON and mea-
sure voltage between “B/W” terminal of sen-
sor connector and body ground.
Is it 10 – 14 V?Go to step 4.“B/W” circuit open.
4 Measure voltage between “R/W” terminal of
sensor connector and body ground.
Is it 0 V?Go to step 5.“R/W” circuit shorted to
power circuit.
5 1) Ignition switch OFF.
2) Check that “R/W” circuit is free from open or
short to ground and “Or/B” circuit. (See [B])
Is it in good condition?“Or/B” circuit open.
If circuit is OK, substitute
a known-good ABS
hydraulic unit / control
module assembly.“R/W” circuit open or
shorted to ground or “Or/
B” circuit.
1. ABS hydraulic unit / control module connector
2. Lock position
3. Unlock position
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Downloaded from www.Manualslib.com manuals search engine ANTILOCK BRAKE SYSTEM (ABS) 5E-21
DTC C1021 (DTC 21), DTC C1022 (DTC 22) – Right Front Wheel Speed Sensor
Circuit
DTC C1025 (DTC 25), DTC C1026 (DTC 26) – Left Front Wheel Speed Sensor
Circuit
DTC C1031 (DTC 31), DTC C1032 (DTC 32) – Right Rear Wheel Speed Sensor
Circuit
DTC C1035 (DTC 35), DTC C1036 (DTC 36) – 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.
1. Ignition switch 4. Right front wheel speed sensor 7. ABS hydraulic unit / control module connector of harness
2. ABS hydraulic unit / control module assembly 5. Left rear wheel speed sensor
3. Left front wheel speed sensor 6. Right rear wheel speed sensor
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
“ABS DIAG. FLOW TABLE” in this section, 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.
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Downloaded from www.Manualslib.com manuals search engine 5E-22 ANTILOCK BRAKE SYSTEM (ABS)
INSPECTION
Step Action Yes No
1 1) Disconnect the applicable sensor connector with ignition
switch OFF.
2) Measure resistance between sensor terminals.
Resistance of wheel speed sensor: 1.4 – 1.8 kΩ (at
20°C, 68°F)
3) Measure resistance between each terminal and body
ground.
Insulation resistance: 1MΩ or higher
Were measured resistance values in step 2) and 3) as spec-
ified? (See [A])Go to step 2. Replace sensor.
2 1) Ignition switch OFF.
2) Disconnect connector from ABS hydraulic unit / control
module assembly. (See [B])
3) Check for proper connection to ABS hydraulic unit / con-
trol 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 0V?Go to step 3. Sensor positive cir-
cuit shorted to
power.
3 1) Ignition switch OFF.
2) Connect connector to sensor.
3) Measure resistance between sensor terminals at mod-
ule 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.
4 1) Remove wheel speed sensor.
2) Check sensor for damage or foreign material being
attached.
Is it in good condition? (See [C])Go to step 5. Clean or replace
sensor.
5 Check visually through wheel speed sensor installation hole
for following.
Ring serration (teeth) neither missing or damaged.
No foreign material being attached.
Ring not being eccentric.
Wheel bearing free from excessive play.
Are they in good condition? (See [D])Go to step 6. Clean, repair or
replace.
6 1) 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 [E])
Replace sensor if any.
Referring to “Front Wheel Speed Sensor” in this section,
check output voltage or waveform of sensor. Is proper out-
put voltage or waveform obtained?Substitute a known-
good ABS hydraulic
unit / control module
assembly and
recheck.Replace sensor and
recheck.
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Downloaded from www.Manualslib.com manuals search engine ANTILOCK BRAKE SYSTEM (ABS) 5E-29
On-Vehicle Service
Precaution
When connectors are connected to ABS hydraulic unit / control
module assembly, do not disconnect connectors of sensors, fuse
etc. and turn ignition switch ON. Then DTC will be set in ABS con-
trol module.
ABS Hydraulic Unit Operation Check
1) Check that basic brake system other than ABS is in good
condition.
2) Check that battery voltage is 11 V or higher.
3) With ABS warning lamp, check that no abnormality is
detected in ABS. Refer to “Diagnostic Trouble Code (DTC)
Check” in this section.
4) Lift up vehicle.
5) Set transmission to neutral and release parking brake.
6) Turn each wheel gradually by hand to check if brake drag-
ging occurs. If it does, correct.
7) With diag. switch terminal (3) of monitor connector (1) con-
nected to ground terminal (2) by using service wire (4), turn
ignition switch ON and check if ABS warning lamp indicates
DTC 12.
When other DTC’s appear on display, refer to “ABS Diagnos-
tic Flow Table” in this section.
8) Turn ignition switch OFF.
9) Perform following checks with help of another person.
Brake pedal (1) should be depressed and then ignition
switch (2) turned ON by one person and wheel (3) should be
turned by another person’s hand. At this time, check that:
Operation sound of solenoid is heard and wheel turns only
about 0.5 sec (Brake force is depressurized).
Operation sound of pump motor is heard and pulsation is felt
at brake pedal.
10) If all 4-wheels cannot be checked during one ignition cycle
(OFF → ON), repeat Steps 8) and 9) till all 4 wheels are
checked.
If a faulty condition is found in Steps 9) and 10), replace
hydraulic unit.
11) Turn ignition switch OFF.
12) Remove service wire from monitor connector.
Page 349 of 687
Downloaded from www.Manualslib.com manuals search engine 5E-32 ANTILOCK BRAKE SYSTEM (ABS)
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 1 full rota-
tion to 1 1/3 rotation per second, check AC voltage of sensor.
Output AC voltage at 1 to 1 1/3 rotation per second
: 120 mV or more at 42 – 54 Hz
If measured voltage is not as specified, check sensor, rotor and
their installation conditions.
1. Front wheel speed sensor 3. Knuckle
2. Sensor ring
1. Wheel speed sensor coupler
2. Right wheel sensor terminals
3. Left wheel sensor terminals
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Downloaded from www.Manualslib.com manuals search engine ANTILOCK BRAKE SYSTEM (ABS) 5E-33
Reference
When using oscilloscope for this check, check if peak-to-peak
voltage (1) meets specification and waveform is complete.
Peak-to-peak voltage at 1 to 1 1/3 rotation per second
: 340 mV or more at 42 – 54 Hz
REMOVAL
1) Disconnect negative cable at battery.
2) Disconnect front wheel speed sensor coupler (3).
3) Hoist vehicle and remove wheel.
4) Remove harness clamp bolts (2) and front wheel speed sen-
sor (1) from knuckle.
SENSOR INSPECTION
Check sensor for damage.
Check sensor for resistance.
If any malfunction is found, replace.
Resistance between terminals of sensor
: 1.2 – 1.6 k
Ω at 20 °C (68 °F)
Resistance between terminal and sensor body
: 1 M
Ω or more
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.
1. Right wheel sensor terminals
2. Left wheel sensor terminals
Page 351 of 687
Downloaded from www.Manualslib.com manuals search engine 5E-34 ANTILOCK BRAKE SYSTEM (ABS)
SENSOR RING INSPECTION
Check ring teeth for being missing, damaged or deformed.
Turn drive shaft and check if ring rotation is free from eccen-
tricity 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 (1) and
ring.
2) Install it by reversing removal procedure.
Tightening torque
Front wheel speed sensor bolt and front wheel speed sen-
sor harness clamp bolts
(a) : 10 N·m (1.0 kg-m, 7.2 lb-ft)
3) Check that there is no clearance between sensor and
knuckle.
CAUTION:
Do not pull wire harness or twist more than necessary
when installing front wheel speed sensor.
2. Bolt
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Downloaded from www.Manualslib.com manuals search engine ANTILOCK BRAKE SYSTEM (ABS) 5E-35
Front Wheel Sensor Ring
REMOVAL
1) Remove wheel hub with sensor ring. Refer to “Wheel Hub /
Bearing / Oil Seal” in Section 3D.
2) Remove sensor ring (1) from wheel hub (2) as shown.
INSPECTION
Check ring teeth for being missing, damaged or deformed.
Check sensor ring (1) for being deformed.
Check that no foreign material is attached.
If any malcondition is found, repair or replace.
INSTALLATION
1) Install sensor ring (3) as shown.
2) Install wheel hub, brake disc, brake caliper, locking hub and
wheel.
Refer to “Wheel Hub / Bearing / Oil Seal” in Section 3D. CAUTION:
Pull out sensor ring (1) from wheel hub (2) gradually and
evenly. Attempt to pull it out partially may cause it to be
deformed.
3. Vise
4. Lever
NOTE:
Pipe (2) used here should have inner diameter of 90
mm (3.55 in) – 96 mm (3.77 in) and its outside should
not contact teeth of sensor ring.
Use care not to insert wheel hub diagonally.
1. Steel plate
4. Wheel hub
5. Hydraulic press