ABS <4WD> -Troubleshooting35B-9
INSPECTION PROCEDURE FOR DIAGNOSIS CODES
Code Nos.11, 12, 13 and 14 Wheel speed sensor
(open circuit or short circuit)Probable cause
Code Nos.21, 22, 23 and 24 Wheel speed sensor
Code Nos. 11, 12, 13 and 14 are output if the ABS-ECU detects an open circuit
or short-circuit in the (+) wire or ( - ) wire in any one of the four wheel speed sensors.DMalfunction of wheel speed sensor
DMalfunction of wiring harness or connector
DMalfunction of hydraulic unit and ABS-ECU
Code Nos. 21, 22, 23 and 24 are output in the following cases.
DWhen there is no input from any one of the four wheel speed sensors when travelling
at several km/h or more, even though open circuit can not be verified.
DWhen a chipped or blocked-up ABS rotor is detected and if the anti-lock system
operates continuously because a malfunctioning sensor or a warped ABS rotor
is causing sensor output to drop.DMalfunction of wheel speed sensor
DMalfunction of wiring harness or connector
DMalfunction of ABS rotor
DToo much gap between the sensor and the ABS rotor
DMalfunction of hydraulic unit and ABS-ECU
DMalfunction of wheel bearing
NG
NG
Replace
OK
Check the harness wire, and repair if necessary.
DBetween each wheel speed sensor and ABS-ECU
NG
Repair
OK
Wheel bearing check
(Refer to GROUP 26 and
GROUP 27 - On-vehicle
Service.)
NG
Repair
NG
Replace the hydraulic unit and ABS-ECU.
OK
Check the trouble
symptom.
Check the following connector:B-123
OK
ABS rotor check
(Refer to P.35B-34.)NG
Replace
NG
Wheel speed sensor
check
(Refer to P.35B-34.)NG
Replace
OK
Wheel speed sensor output voltage check (Refer to P.35B-26.)OK
Check the trouble
symptom.
OK
Check the following connectors:
A-03, A-37, A-43
OK
Measure at the ABS-ECU connector B-123.
DDisconnect the connector, and measure at the harness side
connector.
DResistances between 6 and 7, 8 and 9, 22 and 31, 29 and
30
OK:1.24 - 1.64 kΩNGWheel speed sensor check (Refer to P.35B-34.)
Wheel speed sensor installation checkNG
Repair
ABS <4WD> -Troubleshooting35B-10
Code No.16 ABS-ECU power supply system (abnormal
voltage drop or rise)Probable cause
This code is output if the ABS-ECU power supply voltage drops below or rises above
the rated values.
Furthermore, turning the ignition switch to ACC will erase this code.DMalfunction of battery
DMalfunction of wiring harness or connector
DMalfunction of hydraulic unit and ABS-ECU
Caution
If battery voltage drops or rises during inspection, this code will be output as well. If the voltage
returns to standard value, this code is no longer output.
Before carrying out the following inspection, check the battery level, and refill it if necessary.
NGNG
Repair
NG
Replace the hydraulic unit and ABS-ECU.
NG
Repair
Check the harness wire, and repair if necessary.
DBetween ignition switch (IG2) and ABS-ECU
OK
Check the trouble
symptom.
OK
Check the trouble
symptom.
OK
Check the following connector:B-123
NGCheck the following connectors:B-123, C-128
DDisconnect the connector, and measure at the harness side
connector.
DStart the engine. Voltage between 10 and body earth
OK:System voltage
ABS <4WD> -Troubleshooting35B-11
Code No.32 Longitudinal G sensor systemProbable cause
This code is output in the following cases.
DIf the longitudinal G sensor output voltage is less than 0.5 V or more than 4.5 V
DIf the longitudinal G sensor output voltage does not change
DMalfunction of wiring harness or connector
DMalfunction of hydraulic unit and ABS-ECU
(1) NG
NG
Repair
NG
Check the harness wire, and repair if necessary.
DBetween ignition switch and longitudinal G sensor
OK
Check the trouble
symptom.
Check the following connectors:D-32, C-210, C-213
NG
Repair
NG
OK
Check the trouble
symptom. OK
(2) NG
Measure at the longitudinal G sensor connector D-32.
DDisconnect the connector, and measure at the harness side
connector.
(1) Voltage between 1 and body earth (Ignition switch: ON)
OK:System voltage
(2) Continuity between 3 and body earth
OK:Continuity
Repair
Check the following connectors:B-123, C-128
NGOK
Repair
Check the harness wire.
DBetween longitudinal G sensor and ABS-ECU
Replace the hydraulic unit and ABS-ECU.
MB991348
D-32 Harness
side connector
NG
OK
NG
Repair
NG
OK
Check the trouble
symptom.
Check the following connectors:B-123, C-128, D-32
DRemove the longitudinal G sensor. (Refer to P.35B-35.)
DConnect the special tool between the harness side connector
D-32 and the longitudinal G sensor.
DIgnition switch: ON
DVoltage between 2 and body earth
OK:2.4 - 2.6 V (horizontal position)
3.3 - 3.7 V (with front mark downward)
NGOK
Repair
Check the harness wire.
DBetween longitudinal G sensor and ABS-ECU
Replace the hydraulic unit and ABS-ECU.
Replace the longitudinal G sensor.
ABS <4WD> -Troubleshooting35B-12
Code Nos.41, 42, 43 and 44 Solenoid valveProbable cause
Code No.52 Valve relay problem (stays off)
Code No.53 Motor relay problem (stays off)
Code No.55 Motor system (seized pump motor)
These codes are output if there is an open circuit or short-circuit in the ABS-ECU
power supply circuit (power supply circuit for solenoid valve and motor), or the internal
circuit in the hydraulic unit and ABS-ECU is defective.DMalfunction of wiring harness or connector
DMalfunction of hydraulic unit and ABS-ECU
NG
Repair
NG
Check the harness wire, and repair if necessary.
DBetween fusible link No.3 and ABS-ECU
NG
Repair
NG
Replace the hydraulic unit and ABS-ECU.
OK
Check the trouble
symptom.
Check the following connector:B-123
OK
OK
Check the trouble
symptom.
Check the following connector:A-12Measure at the ABS-ECU connector B-123.
DDisconnect the connector, and measure at the harness side
connector.
DVoltage between 11 and body earth, and between 33 and body
earth
OK:Battery voltageNG
ABS <4WD> -Troubleshooting35B-13
Code No.71 Lateral G sensor systemProbable cause
This code is output in the following cases.
DIf lateral G sensor output voltage is less than 0.5 V or more than 4.5 V
DIf the lateral G sensor output voltage do not change
DMalfunction of wiring harness or connector
DMalfunction of hydraulic unit and ABS-ECU
(1) NG
NG
Repair
NG
Check the harness wire, and repair if necessary.
DBetween ignition switch and lateral G sensor
OK
Check the trouble
symptom.
Check the following connectors:D-33, C-210, C-213
NG
Repair
NG
OK
Check the trouble
symptom. OK
(2) NG
Measure at the lateral G sensor connector D-33.
DDisconnect the connector, and measure at the harness side
connector.
(1) Voltage between 1 and body earth (Ignition switch: ON)
OK:System voltage
(2) Continuity between 3 and body earth
OK:Continuity
Repair
Check the following connectors:B-123, C-128, D-33
NGOK
Repair
Check the harness wire.
DBetween lateral G sensor and ABS-ECU
Replace the hydraulic unit and ABS-ECU.
MB991348
D-33 Harness
side connector
NG
OK
NG
Repair
NG
OK
Check the trouble
symptom.
Check the following connectors:B-123, C-128, D-33
DRemove the lateral G sensor. (Refer to P.35B-35.)
DConnect the special tool between the harness side connector
D-33 and the lateral G sensor.
DIgnition switch: ON
DVoltage between 2 and body earth
OK:2.4 - 2.6 V (horizontal position)
OK:3.3 - 3.7 V (with front mark downward)
NGOK
Repair
Check the harness wire.
DBetween lateral G sensor and ABS-ECU
Replace the hydraulic unit and ABS-ECU.
Replace the lateral G sensor.
ABS <4WD> -Troubleshooting35B-14
Code No.81 Steering wheel sensor (ST-1) system (open
circuit or short circuit)Probable cause
Code No.82 Steering wheel sensor (ST-2) system (open
circuit or short circuit)
Code No.83 Steering wheel sensor (ST-N) system (open
circuit or short circuit)
These codes are output if there is a fault in the steering wheel sensor, an open circuit
or short circuit in the steering signal line, or the internal circuit in the hydraulic unit
and ABS-ECU is defective.DMalfunction of steering wheel sensor
DMalfunction of wiring harness or connector
DMalfunction of hydraulic unit and ABS-ECU
NG
Repair
Replace the hydraulic unit and ABS-
ECU. OK NG YES
Repair
NOAre the diagnosis code Nos.81, 82 and
83 output at the same time?
OKCheck the following connectors:
B-123, C-128
C-147
YES
NO
Is the ACD system diagnosis code
No.31 output at the same time?
NG
Check the trouble symptom.
(1) NG
(2) NGNG
Repair
NG
OK
Check the trouble
symptom.
Check the following connectors:
C-102, C-209, C-210, C-230
Check the harness wire, and repair if
necessary.
DBetween ignition switch and steering
wheel sensor
NG
OK
Check the trouble
symptom.
Check the following connectors:
C-08, C-230
Check the harness wire, and repair if
necessary.
DBetween steering wheel sensor and
body earth
OK
Measure at the steering wheel sensor
connector C-230.
DDisconnect the connector, and
measure at the harness side
connector.
(1) Voltage between 2 and body earth
(Ignition switch: ON)
OK:System voltage
(2) Continuity between 3 and body earth
OK:Continuity
NG
RepairOK
Check the harness wire.
DBetween ABS-ECU and steering
wheel sensor NG
Repair
NG OK
Check the trouble
symptom.
Check the following connectors:
C-133, C-228, B-109
NG
Repair
Check the harness wire.
DBetween ABS-ECU and steering
wheel sensor
OK
Replace the steering wheel sensor. NG
Time Voltage
2.7 - 4.4 V
0.8 - 2.1 V
Variations in voltage when turning the steering wheel laterally
Measure at the steering wheel sensor connector C-230.
DConnect the connector and measure by turning the steering wheel laterally in the neutral
position.
DIgnition switch: ON
(1) Voltage between 1 and body earth
(2) Voltage between 4 and body earth
(3) Voltage between 5 and body earth
OK:Refer to the figure below
ABS <4WD> -Troubleshooting35B-15
INSPECTION CHART FOR TROUBLE SYMPTOMS
Trouble symptomsInspection procedure
No.Reference page
Communication between the MUT-IIand the whole system is not
possible.135B-16
Communication between the MUT-IIand the ABS-ECU is not possible.235B-17
When the ignition key is turned to “ON” (engine stopped), the ABS
warning lamp does not illuminate.335B-18
Even after the engine is started, the ABS warning lamp remains
illuminated.435B-18
In the inspection with MUT-II service data, the parking brake switch is not
turned ON or turn OFF.535B-19
The neutral position learning of the steering wheel sensor is not finished.635B-20
Faulty ABS operation735B-21
Caution
1. If steering movements are made when driving at high speed, or when driving on road surfaces
with low frictional resistance, or when passing over bumps, the ABS may operate even though
sudden braking is not being applied. Because of this, when getting information from the customer,
check if the problem occurred while driving under such conditions as these.
2. During ABS operation, the brake pedal may vibrate or may not be able to be depressed. Such
phenomena are due to intermittent changes in hydraulic pressure inside the brake line to prevent
the wheels from locking and is not an abnormality.
ABS <4WD> -Troubleshooting35B-16
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
Inspection Procedure 1
Communication between the MUT-IIand the whole system
is not possible.
Probable cause
The cause may be a malfunction of the power supply circuit or the earth circuit of
the diagnosis connector.DMalfunction of diagnosis connector
DMalfunction of wiring harness or connector
NG
Repair
NG
Check the harness wire, and repair if necessary.
DBetween fusible link No.1 and diagnosis connectorOK
Check the trouble
symptom.
NG
Replace the MUT-II.
NG
Repair
NG
Check the harness wire, and repair if necessary.
DBetween diagnosis connector and earth
OK
Check the trouble
symptom.OK
Check the trouble symptom.
Measure at the diagnosis connector C-22.
DContinuity between 4 and body earth, and between 5 and body
earth
OK:ContinuityNGCheck the following connector:C-22
OK
Measure at the diagnosis connector C-22.
DVoltage between 16 and body earth
OK:System voltageNGCheck the following connectors:
C-22, C-35