MANUAL TRANSMISSION - Troubleshooting
INSPECTION CHART FOR TROUBLE SYMPTOMS
Trouble symptomInspection
procedure No.Reference
page
No communication possible between MUT-IIand all systems.122A-31
No communication possible between MUT-IIand 4WD-ECU.222A-32
ACD mode indicator lamp does not light up when the ignition switch is set to ”ON“
(engine is stopped).322A-33
More than two ACD mode indicator lamps remain lit even after the engine is started422A-34
The ACD does not operate (no diagnostic code).522A-34
The AYC does not operate (no diagnostic code).6Refer to
GROUPThe rear tire sounds when turning at low speed corners (vehicle slows down)7GROUP
27B.
Noise is produced from the torque transfer differential during turning.8
27B.
INSPECTION PROCEDURES FOR TROUBLE SYMPTOMS
Inspection procedure 1
No communication possible between MUT-IIand all
systems.
Probable cause
The diagnosis connector power supply circuit, earth circuit, or MUT-IImay be
faulty.DDiagnostic connector fault
DHarness or connector fault
DMUT-IIfault
OK
NG
NG
Check the harness between the fusible link No.1 and
diagnosis connector.
DCheck for open circuit or damage of the power line.
NG→Repair
OK
Check the trouble symptoms.
Measure at diagnosis connector C-22.
DVoltage between terminal 16 and body earth
OK:System voltageNGCheck the following connectors:
NG→Repair
Check the harness between the body earth and diagnosis
connector.
DCheck for open circuit and damage of the earth line.
NG→Repair
OK
Replace the MUT-II.
Measure at diagnosis connector C-22.
DResistance between terminals 4 and 5 and body earth.
OK:2Ωor less
MANUAL TRANSMISSION - Troubleshooting
Inspection procedure 2
No communication is possible between the MUT-IIand
4WD-ECU.
Probable cause
The diagnostic output circuit, 4WD-ECU power supply circuit, earth circuit, or
4WD-ECU may be faulty.DHarness or connector fault
D4WD-ECU fault
NG OK OK
NG OK OK
NG OK
OK
NG
NG
NG
Check the trouble symptoms.
Check the harness between the 4WD-ECU and earth.
DCheck for open circuit and damage of the earth line.
NG→Repair
Check the following connectors:
NG→Repair
Check the harness between the ignition switch and 4WD-ECU.
DCheck for open circuit or damage of the power line.
NG→Repair
Check the trouble symptoms.
Measure at 4WD-ECU connector C-44.
DMeasure the ECU terminal voltage.
DIgnition switch: ON
DVoltage between terminal 13 and body earth
OK:System voltageCheck the following connectors:
NG→Repair
Check the harness between the 4WD-ECU and diagnosis
connector.
DCheck for open circuit and damage of the power line.
NG→Repair
Check the trouble symptoms.
Measure at diagnosis connector C-22 and 4WD-ECU
connector C-43.
DResistance between terminal 1 of C-22, and terminal 46 of
C-43
DResistance between terminal 7 of C-22 and terminal 35 of
C-43
OK: 2Ωor lessCheck the following connectors:
NG→Repair
Replace the 4WD-ECU.
Measure at 4WD-ECU connectors C-43 and C-44.
DDisconnect the connector and measure at the harness
side.
DResistance between terminal 26 of C-44 and body earth
DResistance between terminal 42 of C-43 and body earth
OK:2Ωor less
NG OK
Check the trouble symptoms.
Check the following connectors:C-43, C-44
NG→Repair
MANUAL TRANSMISSION - Troubleshooting
Inspection procedure 3
The ACD mode indicator lamp does not light up when the
ignition switch is turned “ON” (engine stop).
Probable cause
The ACD mode indicator lamp circuit or 4WD-ECU may be faulty.DHarness or connector fault
DACD mode indicator lamp assembly fault
D4WD-ECU fault
OK OK OKOK
NG
OK
NG
NG
NG
Check the harness between the ACD mode indicator lamp
assembly and 4WD-ECU.
DCheck for open and damage of the power line.
NG→Repair
Replace the 4WD-ECU.
Measure at 4WD-ECU connector C-43.
DDisconnect the connector and test at the harness side.
DIgnition switch: ON
DBody earth terminals 40, 51, and 52.
OK:The indicator lamp lights up.
Check the trouble symptoms.
Measure at combination meter connector C-01.
DDisconnect the connector and measure at the harness
side.
DIgnition switch: ON
DVoltage between terminal 9 and body earth
OK:System voltageCheck the following connectors:
NG→Repair
Check the trouble symptoms.
Check the ACD mode indicator lamp assembly.
NG→Replace
Check the harness between the ignition switch and ACD
mode indicator lamp assembly.
DCheck for open circuit or damage of the power line.
NG→Repair
Check the following connectors:
NG→Repair
OK
NG
Check the trouble symptoms.
Check the following connector:C-43
NG→Repair
MANUAL TRANSMISSION - Troubleshooting
Inspection procedure 4
More than two ACD mode indicator lamps remain lit even
after the engine starts
Probable cause
The output circuit of the ACD mode indicator lamp may be faulty.DHarness or connector fault
D4WD-ECU fault
DACD mode indicator lamp assembly fault
NOTE
This phenomenon occurs only when communication with the MUT-IIis possible (4WD-ECU power supply
fault) and at the same time, no diagnostic code (no trouble code) is output.
NO
Replace the 4WD-ECU.
Do all the ACD mode indicator lamps go off when 4WD-ECU
connector C-43 is disconnected?
YES
Replace the ACD mode indicator lamp assembly.OK
NG
Check the trouble symptoms.
Check the following connectors:
NG→Repair
OK
Check the harness between the ACD mode indicator lamp
assembly and 4WD-ECU.
DCheck for ground and short circuit of output line.
NG→Repair
Inspection procedure 5
ACD does not operate (No diagnosis code)
Probable cause
Insufficient operating oil, oil leakage, faulty operations of the oil pressure unit, and
faulty operations of the ACD transfer may be suspected.DLeakage of transfer oil
DInsufficient transfer oil
DLeakage of oil pressure line
DInsufficient fluid
DHydraulic unit fault
DACD transfer fault
NOTE:
1. This malfunction is restricted to only when no diagnostic code (no trouble code) is output.
2. *: Refer to GROUP 22B.
OK
NG OKNG OKNG
NG
NO
NG
OK
Replenish transfer oil.
Replace the oil pressure unit.
Have foreign particles mixed into the oil pressure line?
YES→Repair
Check the hydraulic pressure (P.22A-43).Perform bleeding (P.22A-42).
Check the fluid (P.22A-41).Check for leakage of the oil pressure line.
NG→Repair
Check the transfer oil (P.22A-40).Check for leakage of the transfer oil.
NG→Repair
Check the trouble symptoms.
Replace the ACD transfer.*OK
Replenish the fluid.
OK
NG
Check the operations of the ACD (P.22A-42).Check the trouble symptoms.
MANUAL TRANSMISSION - Troubleshooting
CHECK AT 4WD-ECU TERMINALS
NOTE:
1. *1indicates the eliminated terminal when only ACD is installed.
2. *2indicates the terminal added when only ACD is installed.
Termi-
nal no.
Check itemCheck conditionNormal state
1Proportional valve
Operate the Proportional
valveintheactuatortest
While executing the actuator testSystem voltage
(Item No.01).
3*1Proportional valve
Operate the Proportional
valveintheactuatortest
While executing the actuator testSystem voltage
(Item No. 02).
6Wheel speed sensor
FL
Vehicle is stopping1 V or lessp
7Wheel speed sensor
RR
Vehicle is stopping1 V or lessp
8Wheel speed sensor
RL
Vehicle is stopping1 V or lessp
9Wheel speed sensor
FR
Vehicle is stopping1 V or lessp
10Pressure sensor earthAny time1 V or less
11Lateral G sensorIgnition switch: ON
Vehicle horizontal state2.4 - 2.6 V
134WD-ECU power sup-
l
Ignition switch: OFF0Vpp
plyIgnition switch: ONSystem voltage
14*1Directional valve
valve
actuator test (Item No.
07)After completing the actuator test1 V or less
15*1Directional valve
Operate the directional
valve
While executing the actuator testSystem voltage
tor test (Item No. 06)After completing the actuator test1 V or less
16Electric pump relay
l
When the electric pump motor is not operating0Vppy
power supplyWhile the electric pump motor is operatingSystem voltage
19*2Wheel speed sensor
earth
20*2Wheel speed sensor
earth
21*2Wheel speed sensor
earth
22*2Wheel speed sensor
earth
23Longitudinal G sensorIgnition switch: ON
Vehicle horizontal state2.4 - 2.6 V
MANUAL TRANSMISSION - On-vehicle Service22A-44
(2) If the hydraulic unit function has been stopped by
fail-safe, the hydraulic unit cannot be forcibly driven.
6. Check that the generated oil pressure of the hydraulic
unit satisfies the standard value.
Standard value: 1.0 – 1.6 MPa
Caution
While the oil pressure is checked, add fluid as
necessary to ensure that it is left in the oil reservoir
during the entire procedure.
7. If the measured value exceeds the standard value, replace
the hydraulic unit.
8. Connect the hydraulic unit and transfer connector
assembly, and tighten the flare nut at the specified torque.
Tightening torque: 34±5 N·m (when screw is dry)
26±4 N·m (when screw is applied with oil)
9. Supply the specified fluid up to the MAX level of the
oil reservoir, and bleed the oil pressure pipes.
Specified fluid: DIA QUEEN ATF SP III
Quantity:
0.9 dm
3
1.0 dm3
WHEEL SPEED SENSOR OUTPUT VOLTAGE
MEASUREMENT
1. Lift the vehicle, and release the parking brake.
2. Disconnect the 4WD-ECU connector, and measure at
the connector of the harness.
Caution
Insert the probe from the harness of the connector.
Inserting in the terminal side may cause contact fault.
3. Rotate the measured wheel by about 1/2 to 1
rotations/second, and check the output voltage between
the following terminals using a circuit tester (AC mV range)
or oscilloscope.
Terminal No.
Front leftFront rightRear leftRear right
6987
19222120
MANUAL TRANSMISSION - On-vehicle Service22A-45
Output voltage:
Above 70 mV when measured with the circuit
tester
Above 200 mVP-P when measured with the
oscilloscope
4. If the output voltage is lower than the above values, the
following reasons may be suspected. Check or replace
the wheel speed sensor.
DExcessive clearance between the ball piece of the
wheel speed sensor and ABS rotor
DWheel speed sensor faul
INSPECTION PROCEDURE USING OSCILLOSCOPE
After checking the connected state of the harness of the
wheel speed sensor and connector, and measure the output
voltage waveform of each wheel speed sensor on the
oscilloscope as follows.
Start the engine, shift the transmission to the 1st gear to
rotate the driving wheel, and rotate the non-driving wheel
at constant velocity with the hand.
NOTE
1. It is also possible to actually drive the vehicle and observe
the waveform.
2. The output voltage is low if the wheel speed is low and
gradually increases as the speed increases.
PhenomenonProbable causeSolution
Waveform amplitude is too small or
not output at allWheel seed sensor faultReplace the sensor
Excessive waveform amplitude
(However allowed if above the
iilit df100V)
Excessive vibration or concentricity of
the axle hubReplace the hub
(
minimum amplitude of 100 mV)4WD-ECU earth faultCorrect
Noise in the waveform or waveform
ibl
Open circuit of the sensorReplace the sensor
is abnormalOpen circuit of the harnessReplace the harness
Wheel speed sensor installation faultCorrect the installation of the sensor
Chipping or flattening of the ABS rotorReplace the ABS rotor
Caution
As the wheel speed sensor cable follows the movement of the front or rear suspension, it will
change considerably on poor condition roads. Therefore, also observe the output voltage waveform
of the wheel speed sensor with the sensor harness vibrated to simulate special conditions such
as driving in poor road conditions.
When rotated with the hand
When idling (5 – 6 km/h)
1st gear
10.0 ms/DIV
IV/DIV
MANUAL TRANSMISSION -4WD-ECU
4WD-ECU
REMOVAL AND INSTALLATION
Pre-removal and Post-installation Operation
DCowl Side Trim
DFront floor Console Removal and Installation. (Refer to GROUP 52A - Floor Console.)
4.9¶0.9 N m
4WD-ECU
4.9¶0.9 N m
4WD-ECU