2002 MAZDA 6 Temperature control

ELECTRONIC 4WD CONTROL SYSTEM
M–17
M
Memory function
•This function stores DTCs for malfunctions of the input/output signal systems as determined by the failure
detection function. Once a DTC is stored, it is not cleared even if the input/output signal system malfunction
returns to normal when the ignition key is turned to the LOCK position (engine OFF).
•Since DTCs are stored in the non-volatile memory inside the 4WD CM, they are not cleared even if the battery
is disconnected. Therefore, it is necessary to clear the memory when maintenance has been completed. For
clearing DTCs, refer to the procedures in the Workshop Manual.
•When inspecting DTCs using a WDS or equivalent, only one memory stored DTC at a time can be displayed.
Therefore, when multiple DTCs have been stored, it is necessary to inspect for DTCs again after repairing and
clearing the present DTC to ensure that there are no more DTCs present in the memory.
Fail-safe function
•When the failure detection function determines that there is a malfunction, the 4WD warning light illuminates to
alert the driver. At this time, the fail-safe function suspends control or takes other measures to ensure that
driving stability is not lost.
X:Available
*1: Does not illuminate when only the coupling torque request signal from the DSC HU/CM cannot be received.*2: Only integrated DSC control is prohibited when only the coupling torque request signal from the DSC HU/CM
cannot be received.
External tester communication function
•This function allows for the storing and clearing of DTCs due to a communication link between the 4WD CM
and an external tester.
End Of Sie
DTC Malfunction location4WD warning
lightconditionDTC stored in
memoryControl condition
P1887 System wiring Illuminated X Stop
P1888 Differential oil temperature sensor Illuminated X Stop
U0100 PCM communication system Illuminated X Stop
U0101 TCM communication system Illuminated X Stop
U0121 DSC communication system
Illuminated
*1X
Stop*2

M–18
OUTLINE
SUPPLEMENTAL SERVICE INFORMATIONA6E630201018204•The following additions have been made since publication of the Mazda6 Workshop Manual (1730-1*-02C).
Rear wheel hub bolt
•Replacement procedure has been added.
Wheel hub, knuckle
•Removal/installation procedure has been added.
Joint shaft (MZR-CD (RF Turbo))
•Disassembly/assembly procedure has been added.
Joint shaft (4WD)
•Disassembly/assembly procedure has been added.
Front drive shaft (MZR-CD (RF Turbo))
•Disassembly/assembly procedure has been added.
Front drive shaft (4WD)
•Disassembly/assembly procedure has been added.
Rear drive shaft
•Inspection procedure has been added.
•Removal/installation procedure has been added.
•Disassembly/assembly procedure has been added.
Differential oil
•Inspection procedure has been added.
•Replacement procedure has been added.
Oil seal (side gear)
•Replacement procedure has been added.
Oil seal (companion flange)
•Replacement procedure has been added.
Rear differential
•Removal/installation procedure has been added.
•Disassembly procedure has been added.
•Assembly procedure has been added.
Differential oil temperature sensor
•Inspection procedure has been added.
•Removal/installation procedure has been added.
4WD solenoid
•Inspection procedure has been added.
Coupling component
•Removal/installation procedure has been added.
•Disassembly procedure has been added.
•Assembly procedure has been added.
On-board diagnostic
•Electronic 4WD control system have been added.
Troubleshooting
•Electronic 4WD control system have been added.
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OUTLINE

M–20
LOCATION INDEX
REAR DIFFERENTIAL/ELECTRONIC 4WD CONTROL SYSTEM LOCATION INDEXA6E630027100201
.
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8
7
5
4
3
6
1
2
8
7
5
4
3
6
1
2
L.H.D.
R.H.D.
A6J63002002
1 Differential oil
(See M–48 DIFFERENTIAL OIL INSPECTION)
(See M–48 DIFFERENTIAL OIL REPLACEMENT)
2 Oil seal (side gear)
(See M–49 OIL SEAL (SIDE GEAR)
REPLACEMENT)
3 Oil seal (companion flange)
(See M–49 OIL SEAL (COMPANION FLANGE)
REPLACEMENT)
4 Rear differential
(See M–51 REAR DIFFERENTIAL REMOVAL/
INSTALLATION)
(See M–52 REAR DIFFERENTIAL DISASSEMBLY)
(See M–56 REAR DIFFERENTIAL ASSEMBLY)5 Differential oil temperature sensor
(See M–65 DIFFERENTIAL OIL TEMPERATURE
SENSOR INSPECTION)
(See M–65 DIFFERENTIAL OIL TEMPERATURE
SENSOR REMOVAL/INSTALLATION)
6 4WD solenoid
(See M–66 4WD SOLENOID INSPECTION)
7 4WD control module
(See M–66 4WD CONTROL MODURE
INSPECTION)
(See M–67 4WD CONTROL MODURE REMOVAL/
INSTALLATION)
8 Coupling component
(See M–68 COUPLING COMPONENT REMOVAL/
INSTALLATION)
(See M–69 COUPLING COMPONENT
DISASSEMBLY)
(See M–72 COUPLING COMPONENT
ASSEMBLY)

ELECTRONIC 4WD CONTROL SYSTEM
M–65
M
DIFFERENTIAL OIL TEMPERATURE SENSOR INSPECTIONA6E632227100209
Warning
•Hot differential oil may cause severe burns. Do not perform maintenance while differential oil is
hot.
1. Disconnect the negative (-) battery cable.
2. Disconnect the differential oil temperature sensor connector and remove the differential oil temperature sensor.
3. Wrap the differential oil temperature sensor with
plastic wrap and immerse it into a beaker filled
with water. Gradually raise the water
temperature, and measure resistance between
differential oil temperature sensor terminals A and
B.
•If not as specified, inspect the harness for
continuity. If there is normal continuity
between the terminals, replace the differential
oil temperature sensor.
Specification
4. Install the differential oil temperature sensor and connect the connector.
5. Connect the negative (-) battery cable.
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DIFFERENTIAL OIL TEMPERATURE SENSOR REMOVAL/INSTALLATIONA6E632227100210
Warning
•Hot differential oil may cause severe burns. Do not perform maintenance while differential oil is
hot.
1. Disconnect the negative (-) battery cable.
2. Disconnect the differential oil temperature sensor connector.
3. Remove the differential oil temperature sensor.
4. Apply differential oil to the O-ring.
5. Install the differential oil temperature sensor.
Tightening torque
12.7—17.3 N·m {1.3—1.7 kgf·m, 9.4—12.7
ft·lbf}
6. Connect the differential oil temperature sensor
connector.
7. Connect the negative (-) battery cable.
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ELECTRONIC 4WD CONTROL SYSTEM
Water temperature (°C {°F}) Resistance (kirohm)
0 {32} 91—100
10 {50} 56—61
20 {68} 35—39
30 {86} 23—25
40 {104} 14—17
50 {122} 10—11
60 {140} 7.1—7.9
70 {158} 5.0—5.6
80 {176} 3.6—4.0
A B
A6J63222101
DIFFERENTIAL OIL
TEMPERATURE SENSOR
A6E63222102

M–66
ELECTRONIC 4WD CONTROL SYSTEM
4WD SOLENOID INSPECTIONA6E6322271002111. Disconnect the negative (-) battery cable.
2. Disconnect the 4WD solenoid connector.
3. Measure resistance between 4WD solenoid
connector terminals A and B.
•If the resistance is not within the specification,
replace the coupling unit.
Resistance
1.5—2.0 ohms
(Rear differential oil temperature at 20°C
{68°F})
4. Connect the 4WD solenoid connector.
5. Connect the negative (-) battery cable.
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4WD CONTROL MODURE INSPECTIONA6E632227100212
Note
•4WD CM terminal voltage can vary depending on measuring conditions and vehicle aging, resulting in
misdiagnosis. Therefore, it is necessary to perform an overall inspection of the input/output systems and
4WD CM to determine which part is malfunctioning.
•With the 4WD CM connector connected, measure voltage by connecting the voltmeter negative (-) lead to
the body ground and positive (+) lead to each 4WD CM terminal.
1. Measure voltage or resistance at each 4WD CM terminal using a voltmeter and an ohmmeter.
•If not as specified, replace the 4WD CM.
Terminal Voltage List (Reference)
A
B
A6J63222103
Terminal SignalInput/
outputConnected
toMeasuring
itemTest conditionVoltage (V)/
ContinuityInspection location
in case of failure
ADifferential oil
temperature
sensor signalInputDifferential oil
temperature
sensorVoltageIgnition
key
ONDifferential oil
temperature
20°C {68°F}3.0•Inspect
differential oil
temperature
sensor
•Inspect related
harness Differential oil
temperature
60°C {140°F}1.4
B——— ——— — —
CDifferential oil
temperature
sensor GND—Differential oil
temperature
sensorContinuity Any condition Yes•Inspect related
harness
D——— ——— — —
E——— ——— — —
F——— ——— — —
GCAN-HInput/
output—Perform measurement during DTC inspection.—
HCAN-LInput/
output—Perform measurement during DTC inspection.—
A
B C
D E
F G
H I
J K
L M
N O
P
A6J63222104

ON-BOARD DIAGNOSTIC
M–75
M
WIRING DIAGRAMA6E637027100201
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ON-BOARD DIAGNOSTIC
IGNITION SWITCH
BATTERY
DIFFERENTIAL OIL
TEMPERATURE
SENSOR4WD CM4WD SOLENOID ELECTRONIC CONTROL
COUPLING
CAN DRIVERINSTRUMENT CLUSTER
CAN-H
CAN-LPCM DSC HU/CM KO
P I
A
C
NH G
TCM
A6E63702002

M–76
ON-BOARD DIAGNOSTIC
ELECTRONIC 4WD CONTROL SYSTEM ON-BOARD DIAGNOSISA6E637027100202Reading DTCs Procedure
1. Connect WDS or equivalent to the vehicle DLC-2
16-pin connector.
2. Retrieve DTC by WDS or equivalent.
•If a DTC is displayed, proceed with inspection
steps for that DTC.
3. After repair, clear DTCs stored in the 4WD CM by
referring to the Clearing DTCs Procedure.
Clearing DTCs Procedures
1. Connect WDS or equivalent to the vehicle DLC-2
16-pin connector.
2. Clear DTCs by WDS or equivalent.
3. Turn the ignition key to OFF.
4. Perform the DTC inspection again, and verify that
no DTC appears.
5. Disconnect the WDS or equivalent.
DTC Table
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DLC-2
DLC-2
L.H.D.
R.H.D.
A6E63702005
DLC-2
DLC-2
L.H.D.
R.H.D.
A6E63702005
DTC
Diagnosis system component Page
WDS or equivalent
P1887 System wiring (See M–77 DTC P1887)
P1888 Differential oil temperature sensor (See M–79 DTC P1888)
U0100 PCM communication (See M–80 DTC U0100)
U0101 TCM communication (See M–80 DTC U0101)
U0121 ABS/DSC communication (See M–80 DTC U0121)

TROUBLESHOOTING
M–81
M
SYSTEM WIRING DIAGRAMA6E638027100201
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TROUBLESHOOTING
IGNITION SWITCH
BATTERY
DIFFERENTIAL OIL
TEMPERATURE
SENSOR4WD CM4WD SOLENOID ELECTRONIC CONTROL
COUPLING
CAN DRIVERINSTRUMENT CLUSTER
CAN-H
CAN-LPCM DSC HU/CM KO
P I
A
C
NH G
TCM
A6E63702002