ALL MODE 4X4 SYSTEM
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COMPONENTS FUNCTION DESCRIPTION
CAN CommunicationEDS0027K
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
CAN COMMUNICATION UNIT (M/T MODELS WITHOUT ESP)
System diagram
Component parts Function
4WD control unit
Controls driving force distribution by signals from each sensor and switch from front wheel driving
mode (100:0) to 4WD mode (50:50).
2WD mode is available by fail-safe function if malfunction is detected in electrical system.
Wheel sensors Detects wheel speed.
4WD solenoid Controls electric controlled coupling by operation signal from 4WD control unit.
Electric controlled coupling Transmits driving force to rear final drive.
4WD mode switch Able to select from 2WD, AUTO or LOCK mode.
4WD warning lamp
Illuminates if malfunction is detected in electrical system of 4WD system.
There is 1 blink in 2 seconds if rotation difference of front wheels and rear wheels is large.
There are 2 blinks in 1 second if load is still applied to driving parts.
4WD indicator lamp Indicate operation with optimal distribution of torque to front/rear wheels.
LOCK indicator lamp Indicate that 4WD system is under direct 4-wheel driving mode.
ABS actuator and electric unit
(control unit) (without ESP) or
ESP/TCS/ABS control unit (with
ESP)Transmits the following signals via CAN communication to 4WD control unit.
Vehicle speed signal
Stop lamp switch signal (brake signal)
ECMTransmits the following signals via CAN communication to 4WD control unit.
Accelerator pedal position signal
Engine speed signal
Unified meter control unit Transmits conditions of parking brake switch via CAN communication to 4WD control unit.
PKIA6458E
ALL MODE 4X4 SYSTEM
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CAN COMMUNICATION UNIT (M/T MODELS WITH ESP)
System diagram
Input/output signal chart
T: Transmit R: Receive Engine speed signal T R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R
Output shaft revolution signal R T
A/C compressor feedback signal TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Engine A/T integrated control signalTR
RT
A/T self-diagnosis signal R TSignals ECM TCMABS actuator
and electric unit
(control unit)4WD control
unitCombination
meter
PKIA6459E
Signals ECMESP/TCS/ABS
control unitSteering angle
sensor4WD control
unitCombination
meter
Stop lamp switch signal T R
Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
A/C switch signal*
1RT
A/C compressor feedback signal*
2TR
ALL MODE 4X4 SYSTEM
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Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
Output shaft revolution signal R T
A/C compressor feedback signal TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
Brake warning lamp signal T R
SLIP indicator lamp signal T R
ESP OFF indicator lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Steering angle sensor signal R T
Engine and A/T integratedTR
RT
A/T self-diagnosis signal R TSignals ECM TCMESP/TCS/
ABS control
unitSteering
angle sensor4WD control
unitCombination
meter
TROUBLE DIAGNOSIS
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Trouble Diagnosis Chart for SymptomsEDS001VJ
If 4WD warning lamp turns ON, perform self-diagnosis. Refer to TF-30, "SELF-DIAG RESULT MODE" .
NOTE:
Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not malfunction.
Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: LOCK mode, steering
wheel is turned fully to either sides, and accelerator pedal was depressed.Symptom Condition Check item Reference page
4WD indicator lamp and LOCK indicator
lamp do not turn ON for approx. 1 second
when the ignition switch is turned to ON.
(4WD indicator lamp and LOCK indicator
lamp check)Ignition switch: ONCAN communication line
TF-44
Power supply and ground for 4WD con-
trol unit
Unified meter control unit
4WD warning lamp does not turn ON when
the ignition switch is turned to ON.
(4WD warning lamp check)Ignition switch: ONCAN communication line
TF-45
Unified meter control unit
4WD warning lamp does not turn OFF sev-
eral seconds after engine started.Engine runningCAN communication line
TF-46
Power supply and ground for 4WD con-
trol unit
Unified meter control unit
4WD solenoid
4WD actuator relay (integrated in 4WD
control unit)
Wheel sensor
4WD mode cannot be switched after engine
is started.Engine running4WD mode switch
TF-47
CAN communication line
Unified meter control unit
Heavy tight-corner braking symptom occurs
when the vehicle is driven in AUTO mode
and the steering wheel is turned fully to
either side after the engine is started. (See
NOTE.)
While driving
AUTO mode
Steering wheel is
turned fully to either
sidesCAN communication line
TF-48
4WD mode switch
Accelerator pedal position signal
4WD solenoid
Mechanical malfunction of electric con-
trolled coupling (clutch sticking etc.)
Vehicle does not enter 4WD mode even
though 4WD warning lamp turned to OFF.Vehicle speed: 10 km/h
(6 MPH) or less4WD solenoid
TF-49
Mechanical malfunction of electric con-
trolled coupling (Mechanical engage-
ment of clutch is not possible.)
Vehicle speed: 10 km/h
(6 MPH) or moreOperating condition of parking brake
4WD solenoid
Mechanical malfunction of electric con-
trolled coupling (Mechanical engage-
ment of clutch is not possible.)
While driving, 4WD warning lamp flashes
rapidly. (When flashing in approx. 1 minute
and then turning OFF.)
Rapid flashing: 2 times/second
While driving
AUTO mode and
LOCK modeProtection function is activated due to
heavy load to electric controlled cou-
pling. (4WD system is not malfunction-
ing.)TF-50
While driving, 4WD warning lamp flashes
slowly. (When continuing to flash until turn-
ing ignition switch OFF)
Slow flashing: 1 time/2 secondsWhile driving
Vehicle speed: 20 km/h
(12 MPH) or moreTire size is different between front and
rear of vehicle.TF-51
TF-28
TROUBLE DIAGNOSIS
4WD Control Unit Input/Output Signal Reference ValuesEDS001VK
4WD CONTROL UNIT INSPECTION TABLE
Specifications with CONSULT-II
Monitored item [Unit] Content Condition Display value
FR RH SENSOR [km/h] or [mph]Wheel speed (Front wheel
right)Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle running
CAUTION:
Check air pressure of tire under
standard condition.Approximately equal to
the indication on speed-
ometer (Inside of ±10%)
FR LH SENSOR [km/h] or [mph]Wheel speed (Front wheel
left)Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle running
CAUTION:
Check air pressure of tire under
standard condition.Approximately equal to
the indication on speed-
ometer (Inside of ±10%)
RR RH SENSOR [km/h] or [mph]Wheel speed (Rear wheel
right)Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle running
CAUTION:
Check air pressure of tire under
standard condition.Approximately equal to
the indication on speed-
ometer (Inside of ±10%)
RR LH SENSOR [km/h] or [mph]Wheel speed (Rear wheel
left)Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle running
CAUTION:
Check air pressure of tire under
standard condition.Approximately equal to
the indication on speed-
ometer (Inside of ±10%)
BATTERY VOLT [V]Power supply voltage for
4WD control unitIgnition switch: ON Battery voltage
THRTL POS SEN [%] Throttle opening conditionWhen depressing accelerator pedal
(Value rises gradually in response to
throttle position.)0 - 100%
ETS SOLENOID [A]Monitored value of current at
4WD solenoidEngine speed
: At idle2WD Approx. 0.000A
AUTO Approx. 0.000A
LOCK Approx. 0.000A
Engine speed
: 3,000 rpm or more con-
stant2WD Approx. 0.000A
AUTO Approx. 0.000 - 1.500A*
LOCK Approx. 2.800A
STOP LAMP SW [ON/OFF]Condition of brake pedal
operationBrake pedal: Depressed ON
Brake pedal: Released OFF
ENG SPEED SIG [RUN/STOP] Condition of engine runningEngine stopped
(Engine speed: Less than 400 rpm)STOP
Engine running
(Engine speed: 400 rpm or more)RUN
ETS ACTUATOR [ON/OFF]Operating condition of 4WD
actuator relay (integrated in
4WD control unit)Engine stopped (Ignition
switch: ON)OFF
Engine running ON
4WD WARN LAMP [ON/OFF] 4WD warning lamp condition4WD warning lamp: ON ON
4WD warning lamp: OFF OFF
4WD MODE SW [2WD/AUTO/
LOCK]Input condition from 4WD
mode switch4WD mode switch2WD 2WD
AUTO AUTO
LOCK LOCK
BRC-86
[ESP/TCS/ABS]
TROUBLE DIAGNOSIS
For Fast and Accurate DiagnosisEFS004H8
PRECAUTIONS FOR DIAGNOSIS
Before performing diagnosis, always read precautions. Refer to BRC-58, "How to Proceed With Diagno-
sis" .
If ESP/TCS/ABS control unit steering angle sensor, steering system parts or suspension system parts
have been replaced, or if alignment has been adjusted, be sure to adjust neutral position of steering angle
sensor before driving. Refer to BRC-51, "
Adjustment of Steering Angle Sensor Neutral Position" .
After diagnosis is finished, be sure to erase memory. Refer to BRC-79, "SELF-DIAGNOSIS" .
When checking continuity and voltage between units, be sure to check for disconnection, looseness,
bend, or collapse of connector terminals. If any malfunction is found, repair or replace connector termi-
nals.
For intermittent symptoms, possible cause is malfunction in harness, harness connector, or terminals.
Move harness, harness connector, and terminals to check for poor connections.
If a circuit tester is used for the check, be careful not to forcibly extend any connector terminal.
To use CONSULT-II to perform self-diagnosis of ESP/TCS/ABS control unit active tests, or work support,
first stop work, then connect CONSULT-II and select “ABS”.
While self-diagnostic results of CONSULT-II shows malfunction, if CONSULT-II active test is performed,
an engine system error may be indicated. In this case, start engine to resume the normal screen.
ESP/TCS/ABS system electronically controls brake operation and engine output. The following symptoms
may be caused by normal operations:
Symptom Symptom description Result
Motor operation noiseThis is noise of motor inside ESP/TCS/ABS control unit. Slight noise
may occur during ESP, TCS, and ABS operation.
Normal
When the vehicle speed goes over 20 km/h (12.5 MPH), motor and
valves operating noise may be heard. It happens only once after IGN
(ignition) is ON. This is a normal status of the system operation check.
System operation check
noiseWhen engine starts, slight “click” noise may be heard from engine room.
This is normal and is part of system operation check.Normal
ESP/TCS operation
(SLIP indicator lamp blink-
ing)TCS may activate momentarily if wheel speed changes when driving
over location where friction coefficient varies, when up/downshifting, or
when fully depressing accelerator pedal.
Normal
Cancel the ESP/TCS
function for the
inspection on a chas-
sis dynamometer. For inspection of speedometer or other instruments, press ESP OFF
SW to turn ESP/TCS function off.
When accelerator pedal is depressed on a chassis dynamometer (fixed
front-wheel type), vehicle speed will not increase. This is not normal. It is
result of TCS being activated by stationary front wheels. Warning lamp
may also illuminate to indicate “sensor system error”. This is also nor-
mal, and is the result of the stationary front wheels being detected. To be
certain, restart engine, and drive vehicle at 30 km/h (19 MPH) or more.
Make sure warning lamp does not illuminate.
ABS operation (Longer stop-
ping distance)On roads with low friction coefficients, such as snowy roads or gravel
roads, vehicles with ABS may require a longer stopping distance. There-
fore, when driving on such roads, avoid overconfidence and keep speed
sufficiently low.Normal
Insufficient feeling of accel-
erationDepending on road conditions, driver may feel that feeling of accelera-
tion is insufficient. This is because traction control, which controls
engine and brakes to achieve optimal traction, has the highest priority
(for safety). As a result, there may be times when acceleration is slightly
less than usual for the same accelerator pedal operation.Normal
LAN-6
[CAN]
CAN COMMUNICATION
TYPE 3/TYPE4
System diagram
Input/output signal chart
T: Transmit R: Receive 4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Engine A/T integrated control signalTR
RT
A/T self-diagnosis signal R TSignals ECM TCMABS actuator
and electric unit
(control unit)4WD control
unitCombination
meter
PKIA9634E
Signals ECMESP/TCS/ABS
control unitSteering angle
sensor4WD control
unitCombination
meter
Stop lamp switch signal T R
Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
A/C switch signal*
1RT
A/C compressor feedback signal*
2TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
Brake warning lamp signal T R
SLIP indicator lamp signal T R
ESP OFF indicator lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
CAN COMMUNICATION
LAN-7
[CAN]
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*1: YD engine models only
*2: QR engine models only
TYPE 5
System diagram
Input/output signal chart
T: Transmit R: Receive MI signal TR
Glow indicator lamp signal*
1TR
Steering angle sensor signal R TSignals ECMESP/TCS/ABS
control unitSteering angle
sensor4WD control
unitCombination
meter
PKIA9635E
Signals ECM TCMESP/TCS/
ABS control
unitSteering
angle sensor4WD control
unitCombination
meter
Stop lamp switch signalRT
TR
P·N range signal R T
A/T position indicator lamp signal T R R
O/D OFF indicator signal T R
Overdrive control switch signal R T
Closed throttle position signal T R
Wide open throttle position signal T R
Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
Output shaft revolution signal R T
A/C compressor feedback signal TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
Brake warning lamp signal T R