Page 1345 of 2000

GF1A TRANSFER – ACTIVE TORQUE CONTROL 4WD SYSTEMTF–17
TF
DIAGNOSIS SYSTEM
1. DESCRIPTION
Active torque control 4WD system data can be read in
the Data Link Connector 3 (DLC3) of the vehicle. When
the system seems to be malfunctioning, use the
intelligent tester (with CAN VIM) to check for
malfunctions and perform repairs. Therefore when there
seems to be a problem with the active torque control
4WD, use the intelligent tester (with CAN VIM) or SST to
check and troubleshoot it.
SST 09843-18040
2. CHECK DLC3
(a) The ECU uses CAN (ISO11898-1) and ISO9141-2
for communication protocol. The terminal
arrangement of the DLC3 complies with SAE J1962
and matches the ISO9141-2 format.
Verify the conditions listed in the table below.
NOTICE:
*: Before measuring the resistance, leave the
vehicle as is for at least 1 minute and do not
operate the ignition switch, other switches or
the doors.
If the result is not as specified, the DLC3 may have
a malfunction. Repair or replace the harness and
connector.
HINT:
Connect the cable of the intelligent tester (with CAN
VIM) to the DLC3, turn the ignition switch ON and
attempt to use the tester. If the display indicates that
a communication error has occurred, there is a
problem either with the vehicle or with the tester.
• If communication is normal when the tester is
connected to another vehicle, inspect the DLC3
of the original vehicle.
H100769E16
Symbols (Terminal No.) Terminal Description Condition Specified Condition
SIL (7) - SG (5) Bus + line During transmission Pulse generation
CG (4) - Body Ground Chassis ground Always Below 1
SG (5) - Body Ground Signal ground Always Below 1
BAT (16) - Body Ground Battery positive Always 11 to 14 V
CANH (6) - CANL (14) HIGH-level CAN bus line Ignition switch OFF* 54 to 69
CANH (6) - BAT (16) HIGH-level CAN bus line Ignition switch OFF* 1 M or higher
CANH (6) - CG (4) HIGH-level CAN bus line Ignition switch OFF* 200
or higher
CANL (14) - BAT (16) LOW-level CAN bus line Ignition switch OFF* 1 M
or higher
CANL (14) -CG (4) LOW-level CAN bus line Ignition switch OFF* 200
or higher
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TF–18GF1A TRANSFER – ACTIVE TORQUE CONTROL 4WD SYSTEM
TF
• If communication is still not possible when the
tester is connected to another vehicle, the
problem may be in the tester itself. Consult the
Service Department listed in the tester's
instruction manual.
3. INDICATOR LIGHT
(a) When a problem occurs in the active torque control
4WD system, the 4WD indicator light on the
combination meter comes ON to inform the driver of
the problem.
DTC CHECK / CLEAR
1. CHECK DTC (When Using Intelligent Tester)
(a) Check the DTCs.
(1) Connect the intelligent tester (with CAN VIM) to
the DLC3.
(2) Turn the ignition switch ON.
(3) Read the DTCs by following the prompts on the
tester screen.
HINT:
Refer to the intelligent tester (with CAN VIM)
operator's manual for further details.
2. CLEAR DTC (When Using Intelligent Tester)
(a) Connect the intelligent tester (with CAN VIM) to the
DLC3.
(b) Turn the ignition switch ON.
(c) Operate the intelligent tester (with CAN VIM) to
clear the codes.
HINT:
Refer to the intelligent tester (with CAN VIM)
operator's manual for further details.
3. CHECK DTC (When not Using Intelligent Tester)
(a) Check the DTCs.
(1) Using the SST, connect terminals TC (13) and
CG (4) of the DLC3
SST 09843-18040
(2) Turn the ignition switch ON.
C128618E02
B127989E01
H100769E10
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GF1A TRANSFER – ACTIVE TORQUE CONTROL 4WD SYSTEMTF–19
TF
(3) Read DTCs from the 4WD indicator light ON the
combination meter.
HINT:
• If the 4WD indicator light does not blink,
perform relevant troubleshooting procedures.
The relevant troubleshooting procedures are
in the sections listed in the table below.
• If more than 1 DTC is detected at the same
time, the DTCs will be displayed in numerical
order.
• As an example, the blinking patterns of the
normal system code and DTCs 11 and 21 are
shown below.
• DTCs are explained in "DIAGNOSTIC
TROUBLE CODE CHART" (see page TF-19).
4. CLEAR DTC (When not Using Intelligent Tester)
(a) Using SST, connect terminals 13 (TC) and 4 (CG) of
the DLC3.
SST 09843-18040
(b) Turn the ignition switch ON.
(c) Clear the DTCs stored in the 4WD control ECU by
depressing the brake pedal 8 times or more within 5
seconds.
(d) Check that the warning light blinks in the normal
system code pattern.
(e) Remove SST from the terminals of the DLC3.
(f) Turn the ignition switch OFF.
HINT:
DTCs cannot be cleared by disconnecting the cable
from the negative (-) battery terminal or removing
the ECU-IG1 fuse.
C108860E08
Section Title See Procedure
4WD Indicator Light does not Come ONTF-40
TC and CG Terminal CircuitTF-42
C108863
Page 1348 of 2000
TF–20GF1A TRANSFER – ACTIVE TORQUE CONTROL 4WD SYSTEM
TF
FAIL-SAFE CHART
1. FAIL-SAFE FUNCTION
• If following malfunctions occur, the 4WD control ECU
will stop the function of 4WD control system or partly
change the function to control the system.
• If a malfunction occurs in the sensor signal or
actuator, the flow of electricity to the linear solenoid of
the electrical coupling is prohibited. As a result, the
system enters front wheel drive condition.
• When a component of the system malfunctions and
the fail-safe function activates, the component
operation is prohibited. However, if the system is
controlling the component and the fail-safe function
activates, the system operation is gradually stopped
to prevent sudden changes in the vehicle condition.
• When system control is not possible, the warning light
is illuminated to stop operation of the system
operation.
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GF1A TRANSFER – ACTIVE TORQUE CONTROL 4WD SYSTEMTF–21
TF
DATA LIST / ACTIVE TEST
1. READ DATA LIST
HINT:
Using the intelligent tester's (with CAN VIM) DATA LIST
allows switch, sensor and other item values to be read
without removing any parts. Reading the DATA LIST
early in troubleshooting is one way to save time.
(a) Connect the intelligent tester (with CAN VIM) to the
DLC3.
(b) Turn the ignition switch ON.
(c) Read the DATA LIST according to the display on the
tester.
4WD control ECU
Item Measurement Item/Range
(Display)Normal Condition Diagnostic Note
4WD WARN LAMP 4WD indicator light /OFF or ON OFF: 4WD indicator light OFF
ON: 4WD indicator light ON-
SLIP INDI LAMP Slip indicator light /OFF or ON OFF: SLIP indicator light OFF
ON: SLIP indicator light ON-
STOP LAMP SW Stop light switch /OFF or ON OFF: Brake pedal released
ON: Brake pedal depressed-
STEERING ANGLE Steering angle value /
Min.: -3276.8 deg
Max.: 3276.7 degMin.: -3276.8 deg
Max.: 3276.7 deg-
FR WHEEL SPD FR wheel speed /
Min.: 0 km/h (0 mph)
Reading : Max.: 326.4 km/h
(202.8 mph)Actual wheel speed Almost no difference from the
speedometer
FL WHEEL SPD FL wheel speed /
Min.: 0 km/h (0 mph)
Reading : Max.: 326.4 km/h
(202.8 mph)Actual wheel speed Almost no difference from the
speedometer
RR WHEEL SPD RR wheel speed /
Min.: 0 km/h (0 mph)
Reading : Max.: 326.4 km/h
(202.8 mph)Actual wheel speed Almost no difference from the
speedometer
RLWHEEL SPD RL wheel speed /
Min.: 0 km/h (0 mph)
Reading : Max.: 326.4 km/h
(202.8 mph)Actual wheel speed Almost no difference from the
speedometer
AMBI TEMP Ambient temperature /
Min.: -128
C (198.4 F)
Max.: 127 C (260.6 F)Min.: -128 (198.4
F)
Max.: 127 (260.6
F)-
COOLANT TEMP Engine coolant temperature /
Min.: 0
C (32 F)
Max.: 127.5
C (261.5 F)Min.: 0
C (32 F)
Max.: 127.5 C (261.5 F)-
LOCK SW 4WD lock switch / OFF or ON OFF: 4WD lock switch off
ON: 4WD lock switch on-
SLC CUR SLC solenoid (4WD linear
solenoid) current /
Min.: 0 A
Max.: 3 AMin.: 0 A
Max.: 3 A-
Page 1350 of 2000
TF–22GF1A TRANSFER – ACTIVE TORQUE CONTROL 4WD SYSTEM
TF
2. PERFORM ACTIVE TEST
HINT:
Performing the intelligent tester's (with CAN VIM)
ACTIVE TEST allows switch and other items to be
operated without removing any parts. Performing the
ACTIVE TEST early in troubleshooting is one way to
save time. The DATA LIST can be displayed during the
ACTIVE TEST.
(a) Connect the intelligent tester (with CAM VIN) to the
DLC3.
(b) Turn the ignition switch ON.
(c) Perform the ACTIVE TEST according to the display
on the tester.
4WD control ECU
Skid control ECU
Item Test Details Diagnostic Note
4WD WARN LAMP 4WD indicator light ON / OFF
ON: 4WD indicator light ON
OFF: 4WD indicator light OFFObserve combination meter
LOCK LAMP 4WD lock light / ON / OFF
OFF: 4WD lock switch OFF
ON: 4WD lock switch ONObserve combination meter
Item Test Details Diagnostic Note
SLIP INDI LAMP SLIP indicator Light / ON / OFF
ON: SLIP indicator light ON
OFF: SLIP indicator light OFFObserve combination meter
Page 1351 of 2000

GF1A TRANSFER – ACTIVE TORQUE CONTROL 4WD SYSTEMTF–23
TF
DIAGNOSTIC TROUBLE CODE CHART
DTC No. Detection Item Trouble Area See page
C1241/94 Low Power Supply Voltage -Battery
-generator
-ECU-IG1
-Wire harness
-4WD control ECUTF-21
C1280/82 Engine Circuit Malfunction -Throttle position sensor
-Throttle position sensor wire
harness and connector
-CAN communication systemTF-24
C1296/96 ABS Malfunction -Wire harness
-4WD control ECU
-Skid control ECU
-Speed sensor
-Yaw rate sensor
-CAN communication systemTF-25
C1297/97 Steering Angle Sensor -Steering angle sensor
-CAN communication system
-Wire harness
-4WD control ECUTF-27
C1298/98 Linear Solenoid Circuit -Wire harness
-Electromagnetic coupling
-4WD control ECUTF-30
C1299/99 Cancellation of 4WD Control -Tire size
-Electromagnetic coupling
-4WD control ECUTF-32
U0073/86 Control Module Communication
Bus OFF-Wire harness (CANH, CANL
circuit)
-4WD control ECUTF-34
U0100/85 Lost Communication with ECM /
PCM "A"-Wire harness (CANH, CANL
circuit)
-4WD control ECU
-ECMTF-34
U0126/84 Lost Communication with
Steering Angle Sensor Module-Wire harness (CANH, CANL
circuit)
-4WD control ECU
-Steering angle sensorTF-34
U0129/83 Lost Communication with Brake
System Control Module-Wire harness (CANH, CANL
circuit)
-4WD control ECU
-Skid control ECUTF-34
Page 1352 of 2000

TF–24GF1A TRANSFER – ACTIVE TORQUE CONTROL 4WD SYSTEM
TF
DESCRIPTION
If a malfunction in the power source circuit occurs, or a malfunction in communication with the skid control
ECU or in a speed sensor occurs, the 4WD control ECU will prohibit operations by the fail-safe function.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Check the condition of each related circuit connector before troubleshooting (see page IN-37).
DTC C1241/94 Low Power Supply Voltage
DTC No. DTC Detection Condition Trouble Area
C1241/94 When one of following conditions is met:
1. When following continues for 10 seconds
or more:
- At a vehicle speed of 3 km/h (2 mph) or
more, voltage of IG1 terminal is 9.5 V or
less.
2. When both of following continue for 60
seconds or more:
- With the voltage of IG1 terminal 9.5 V or
less, communication with the skid control
ECU cannot be performed.
- A malfunction in communication with
skid control ECU.
3. When following continue for 3 seconds or
more:
- With the voltage of IG1 terminal 9.5 V or
more, communication with the skid control
ECU cannot be performed.•Battery
• Generator
•ECU-IG1
• Wire harness (IG1 circuit, GND circuit)
• 4WD control ECU
C128626E02