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Input / Output Signal Table of 4WD Control ModuleS6RW0D3201008
4WD control module outputs the following signals to coupling assembly, indicators, according to the 2WD/4WD switch
operation.
On-Board Diagnostic System DescriptionS6RW0D3201009
For 4WD control system, 4WD control module has the following functions.
• When ignition switch is turned ON with engine at stop, 4WD AUTO indicator (1) and 4WD LOCK indicator (2) turn
on at the same time for 2 seconds in order to check operation of these indicators.
• When 4WD control module detects any malfunction in the following area, 4WD AUTO indicator (1) and 4WD LOCK
indicator (2) flash continuously or turn on and 4WD control module comes into fail-safe mode. For details of fail safe
mode, refer to “Fail-Safe Table”.
– 2WD/4WD switch
– Coupling air temperature sensor
– Coupling assembly
• DTC can be checked by using SUZUKI scan tool (3) connected to DLC (4).
• When 4WD control module detects any malfunction, 4WD control module will switch off the current to coupling
assembly and vehicle is changed to 2WD position.
DLC (Data Link Connector)
Refer to “Data Link Connector (DLC)” under “On-Board Diagnostic System Description in Section 1A”.Output signal (to each component parts)
Coupling
assembly4WD AUTO
indicator4WD LOCK
indicator
Input signal2WD/4WD switch { { {
Coupling air temperature sensor {
ECM {
ABS / ESP® control module { { {
1
2 3
4
I5RW0A320004-01

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CAN Communication System DescriptionS6RW0D3201010
Refer to “CAN Communication System Description in Section 1A” for CAN communication system description.
When 4WD control module receive the signal of abnormal as following information, vehicle is not changed to 4WD-
auto and 4WD-lock position.
4WD Control Module Transmission Data
4WD Control Module Reception Data
ECMCombination
Meter
TransmitDATA 4WD
4WD mode status
4WD auto mode
indication status
4WD lock mode
indication status
4WD diagnostic
trouble codes control
module
4WD clutch
engagement percent
ESP® hydraulic unit /
control module
(if equipped)
4WD clutch control
request impossibility
I7RW01320013-01
Accelerator position
Engine speedECM
DATA
Brake pedal switch signal
4WD
control
moduleWheel speed signal
(front right)
Wheel speed signal
(front left)
Wheel speed signal
(rear right)
Wheel speed signal
(rear left)
ABS hydraulic
unit /control
module
(if equipped)
ESP® hydraulic
unit /control
module
(if equipped)
ABS active
ESP® status signal
Clutch control request for
4WD active
Clutch control request
percent
Engine type signal
Engine torque signal
Receive
I7RW01320002-03

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DTC TableS6RW0D3204007
NOTE
“O” in transfer position indicator column of the above table means indicator lights up when DTC is
detected.
Fail-Safe TableS6RW0D3204008
This function is provided by the safe mechanism that assures safe driveability even when the coupling assembly,
switch, sensor or its circuit fails. The following table shows the fail safe function for each fail condition of sensor,
coupling assembly, switch, 4WD control module or its circuit. DTC No. Detecting itemDetecting condition
(DTC will set when detecting)4WD
position
Indicator
) C12404WD control module power
supply circuit malfunctionBattery voltage is lower than lower limit voltage for
4WD control module diagnosis. {
) C1243Internal circuit malfunction of
4WD control moduleInternal power supply malfunction of 4WD control
module {
) C1250Coupling air temperature sensor
openSensor output voltage too high {
) C1251Coupling air temperature sensor
shortSensor output voltage too low {
) C1252 Coupling assembly open2WD/4WD switch is changed of 4WD lock position,
and then vehicle is not changed for more than 5
seconds. {
) C1253 Coupling assembly short2WD/4WD switch is changed of 4WD lock position,
and then vehicle is not changed for more than 5
seconds. {
) C1254 2WD/4WD switch malfunctionDifferent switch combination from specification is
detected more than 5 seconds. {
) U0073Control module communication
bus offTransmitting and receiving error of 4WD control
module for specified time continuously {
) U0100 Lost communication with ECMReceiving error of 4WD control module from ECM
for specified time continuously {
) U0121Lost communication with ABS /
ESP® control moduleReceiving error of 4WD control module from ABS /
ESP® control module for specified time
continuously {
) U0155Lost communication with
instrument panel cluster control
moduleReceiving error of 4WD control module from
combination meter for specified time continuously {
DTC No. Trouble Area Fail-Safe Operation
)C12404WD control module power supply circuit
malfunction4WD control module controls the current and
fixed the vehicle to 2WD position.
)C1243Internal circuit malfunction of 4WD control
module
)C1250 Coupling air temperature sensor open
)C1251 Coupling air temperature sensor short
)C1252 Coupling assembly open
)C1253 Coupling assembly short
)C1254 2WD/4WD switch malfunction
)U0073 Control module communication bus off
)U0100 Lost communication with ECM
)U0121Lost communication with ABS / ESP® control
module
)U0155Lost communication with instrument panel
cluster control module

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Scan Tool DataS6RW0D3204009
Scan Tool Data Definitions
Accel pedal Pos (Accelerator pedal position) (%)
Accelerator pedal opening ratio detected by signal on
CAN communication line fed from ECM.
Engine Speed (RPM)
This parameter indicates engine revolution calculated by
4WD control module.
4WD mode (2WD / AUTO / LOCK / ABS mode / Yaw
cont / ESP® req)
This parameter indicates 4WD mode according to 2WD/
4WD switch signal status detected by 4WD control
module.
4WD current (A)
This parameter indicates input current of coupling
assembly.
Battery voltage (V)
This parameter indicates battery voltage detected by
4WD control module.Coupling temp (°C, °F)
Coupling temperature detected by coupling air
temperature sensor installed in coupling assembly.
Wheel speed (F), Wheel speed (R) (km/h, mph)
Wheel speed is an ABS / ESP® control module internal
parameter. It is computed by reference pulses from the
wheel speed sensor.
F-R Wheel speed diff (Front-rear wheel speed
differential) (rpm)
This parameter indicates rotation difference between
front wheel and rear wheel detected by 4WD control
module.
4WD duty (%)
This parameter indicates operation rate of coupling
assembly. Scan tool data Vehicle conditionNormal condition / reference
values
) Accel pedal PosIgnition switch ON after
warmed up engineAccelerator pedal released 0 – 5%
Accelerator pedal depressed
fully90 – 100%
) Engine speed At engine idle speed Engine idle speed is display
) 4WD mode2WD/4WD switch selected to 2WD position 2WD
2WD/4WD switch selected to AUTO position AUTO
2WD/4WD switch selected to LOCK position LOCK
ABS operating ABS mode
Ignition switch ON and engine stop Relay off
Stability control operating Yaw cont
ESP® operating ESP® mode
) 4WD current Engine running 0 – 200 mA
) Battery voltage At engine idle speed 10 – 14 V
) Coupling temp Engine running –40 °C – 100 °C (–40 °F – 212 °F)
) Wheel speed (F) Vehicle stop 0 km/h, 0 MPH
) Wheel speed (R) Vehicle stop 0 km/h, 0 MPH
) F-R Wheel speed
DiffVehicle stop 0 rpm
) 4WD dutyIgnition switch ON and 2WD/4WD switch selected to
2WD position0%

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Rear Differential Symptom DiagnosisS6RW0D3204011
4WD Control Symptom DiagnosisS6RW0D3204012
Diagnose 4WD system after performing the following inspections.
• Perform 4WD control system check referring to “4WD Control System Check”. Condition Possible cause Correction / Reference Item
Gear noiseDeteriorated or water mixed lubricantRepair and replenish referring to “Rear
Differential Oil Change”.
Inadequate or insufficient lubricantRepair and replenish referring to “Rear
Differential Oil Change”.
Maladjusted backlash between drive
bevel pinion and gearAdjust as prescribed referring to “Rear
Differential Disassembly and Reassembly”.
Improper tooth contact in the mesh
between drive bevel pinion and gearAdjust or replace referring to “Rear Differential
Disassembly and Reassembly”.
Loose drive bevel gear securing boltsReplace or retighten referring to “Rear
Differential Disassembly and Reassembly”.
Damaged differential gear(s) or
differential pinion(s)Replace referring to “Rear Differential
Inspection”.
Bearing noise(Constant noise) Deteriorated or water
mixed lubricantRepair and replenish referring to “Rear
Differential Oil Change”.
(Constant noise) Inadequate or
insufficient lubricantRepair and replenish referring to “Rear
Differential Oil Change”.
(Noise while coasting) Damaged
bearing(s) of drive bevel pinionReplace referring to “Rear Differential
Inspection”.
(Noise while turning) Damaged
differential side bearing(s) or axle
bearing(s)Replace referring to “Rear Differential
Inspection”.
Oil leakageClogged breather plugClean.
Worn or damaged oil sealReplace.
Excessive oilAdjust oil level referring to “Rear Differential Oil
Change”.
Loose differential carrier boltsReplace or retighten.
Condition Possible cause Correction / Reference Item
4WD system does not
operate2WD/4WD switch faultyCheck switch referring to “2WD/4WD Switch
Inspection”.
Coupling air temperature sensor faultyCheck coupling air temperature sensor
referring to “Coupling Air Temperature Sensor
Inspection”.
Coupling assembly faultyCheck coupling assembly referring to
“Coupling Assembly Inspection”.
Wiring or grounding faultyRepair as necessary.
4WD control module faultyCheck 4WD control module referring to
“Inspection of 4WD Control Module and Its
Circuits”.
MAF sensor faultyCheck MAF sensor and its circuit.
Accelerator pedal position (APP) sensor
faultyCheck accelerator pedal position (APP) sensor
and its circuit.
CKP sensor faultyCheck CKP sensor and its circuit.
Front and/or rear wheel speed sensor
faultyCheck front and/or rear wheel speed sensor
and its circuit.
Steering angle sensor faultyCheck steering angle sensor and its circuit.
ABS / ESP® control module faultyCheck ABS / ESP
® control module and its
circuit.
ECM faultyCheck ECM and its circuit.
NoiseDamaged or worn bearing(s)Refer to “Rear Differential Inspection”.

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DTC U0073: Control Module Communication Bus OffS6RW0D3204022
Refer to “Troubleshooting for CAN-DTC in Section 1A”.
DTC U0100: Lost Communication with ECMS6RW0D3204023
Refer to “Troubleshooting for CAN-DTC in Section 1A”.
DTC U0121: Lost Communication with ABS / ESP® Control ModuleS6RW0D3204024
Refer to “Troubleshooting for CAN-DTC in Section 1A”.
DTC U0155: Lost Communication with Instrument Panel Cluster (IPC) Control ModuleS6RW0D3204025
Refer to “Troubleshooting for CAN-DTC in Section 1A”.
Inspection of 4WD Control Module and Its CircuitsS6RW0D3204026
4WD control module and its circuits can be checked at coupler connected to 4WD control module by measuring
voltage, pulse signal.
CAUTION!
4WD control module cannot be checked by itself. It is strictly prohibited to connect voltmeter or
ohmmeter to 4WD control module with couplers disconnected from it.
Voltage and Signal Check
1) Check voltage using voltmeter (1) connected to each terminal of couplers.
2) Check signal using oscilloscope (2) connected to each terminal of couplers.
NOTE
• As each terminal voltage is affected by the battery voltage, confirm that it is 11 V or more when
ignition switch is turned ON.
• Pulse signal cannot be measured by voltmeter. It can be measured by oscilloscope.
• Item with asterisk (*) in normal voltage column can be read only by oscilloscope.
12
I4JA01332053-01

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Brakes
ABS
Precautions
Precautions in Diagnosing TroublesS6RW0D4500001
To ensure that the trouble diagnosis is done accurately
and smoothly, observe the following and follow “ABS
Check”.
• Diagnostic information stored in ABS control module
memory can be cleared as well as checked by using
SUZUKI scan tool. Before using scan tool, read its
Operator's (Instruction) Manual carefully to have good
understanding as to what functions are available and
how to use it.
• If the vehicle was operated in any of the following
ways, ABS warning light may light momentarily but
this does not indicate anything abnormal in ABS.
– The vehicle was driven with parking brake pulled.
– The vehicle was driven with brake dragging.
– The vehicle was stuck in mud, sand, etc.
– Wheel spin occurred while driving.
– Wheel(s) was rotated while the vehicle was jacked
up.
• Be sure to read “Precautions for Electrical Circuit
Service in Section 00” and “Precaution for CAN
Communication System in Section 00” before
inspection and observe what is written there.
• Be sure to use the trouble diagnosis procedure as
described in “ABS Check”. Failure to follow it may
result in incorrect diagnosis. (Some other diagnosis
trouble code may be stored by mistake in the memory
of ABS control module during inspection.)• When disconnecting ABS hydraulic unit / control
module connector (1), pull up lock lever (2) of
connector.
When connecting, set the connector on ABS hydraulic
unit / control module assembly and pull down the lock
lever (2) until it locks.
• Communication of ECM, BCM, combination meter,
4WD control module (if equipped), keyless start
control module (if equipped), TCM (if equipped), data
link connector and ABS control module is established
by CAN (Control Area Network).
Therefore, be sure to read “Precautions for Installing
Mobile Communication Equipment in Section 00”
before inspection and handling CAN communication
line.
Precautions in On-Vehicle ServiceS6RW0D4500002
When connector is connected to ABS hydraulic unit /
control module assembly, do not disconnect connectors
of sensors with ignition switch ON. Otherwise, DTC will
be set in ABS control module.
[A]: Disconnect C: Pull up to disconnect
[B]: Connect D: Pull down to connect
2 1
CD
[A]
[B]
I5RW0A450001-01

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ABS Hydraulic Unit / Control Module Assembly
Description
S6RW0D4501002
ABS control module is a component of ABS hydraulic
unit / control module assembly and has the following
functions.
Self-Diagnosis Function
ABS control module diagnoses conditions of the system
component parts (whether or not there is any
abnormality) all the time and indicates the results
(warning of abnormality occurrence and DTC) through
the ABS warning light as described.• When ignition switch is turned ON, ABS warning light
lights for 2 seconds to check its circuit.
• When no abnormality has been detected (the system
is in good condition), ABS warning light turns OFF
after 2 seconds.
• When an abnormality in the system is detected, ABS
warning light lights and the area where that
abnormality lies is stored in the memory of EEPROM
in ABS control module.
CAN Communication System DescriptionS6RW0D4501003
Refer to “CAN Communication System Description in Section 1A” for CAN communication system description. ABS
control module communicates control data with each control module as follows.
ABS Control Module Transmission Data
1
I4RS0A450001-01
Wheel speed signal (Front-right)
Wheel speed signal (Front-left)
Wheel speed signal (Rear-right)
Wheel speed signal (Rear-left)
ABS active
ABS indication
EBD indicationCombination Meter
TransmitDATA
ABS control module ECM 4WD control module
I7RW01450001-06