sensor MAZDA 6 2002 Workshop Manual Suplement

ELECTRONIC 4WD CONTROL SYSTEM
M–7
M
OUTLINEA6E632227100201Features
Improved off-road mobility, handling stability, operability, fuel economy and marketability
•An electronic 4WD control system, which automatically optimizes traction distribution to the front and rear
wheels, has been adopted.
Improved serviceability
•A self-diagnostic function has been adopted for the electronic 4WD control system.
Electronic 4WD control system outline
•The newly adopted electronic 4WD control system automatically and optimally controls drive torque distribution
for the front and rear wheels. Due to this off-road mobility, driving stability and fuel economy are improved.
•Based on the input signals from each sensor, the 4WD control modure (4WD CM) determines vehicle driving
and road conditions, and controls output current to the electronic control coupling (4WD solenoid) inside the
rear differential. This control allows for optimal distribution of the drive torque from the engine to the rear
wheels.
•Also, the 4WD CM automatically controls the 4WD, greatly reducing the load on the driver and improving
operability.
Structural view
.
ELECTRONIC 4WD CONTROL SYSTEM
87
5
4
3
6
9
8
7
5
4
3
10
6
1
2
9
10
A6E63222001
1L.H.D.
2 R.H.D.
3 4WD warning light
4 4WD control modure
5 DSC HU/CM6PCM
7TCM
8 Electronic control coupling (4WD solenoid)
9 Differential oil temperature sensor
10 Rear differential

M–8
ELECTRONIC 4WD CONTROL SYSTEM
Components and Functions
System Diagram
.
Part name Function
Electronic control coupling
(4WD solenoid)•Based on a signal from the 4WD CM, it operates the electromagnetic clutch and
transmits drive torque to the rear wheels.
Differential oil temperature
sensor•Informs the 4WD CM of the rear differential oil temperature.
4WD CM•Controls operation of the electronic control coupling (4WD solenoid) based on signals
input from the throttle opening angle, speed, differential oil temperature and other
sensors.
•Outputs coupling control condition and 4WD warning control information as a CAN
signal.
•Controls the on-board diagnostic system and the fail-safe system if there is a malfunction
in the 4WD system.
4WD warning light•Illuminates or flashes to alert driver of a malfunction or control failure in the 4WD system.
PCM•Sends the throttle opening angle and engine speed signals, as CAN signals, to the 4WD
CM.
TCM•Sends the selector lever position and gear position signals, as CAN signals, to the 4WD
CM.
DSC HU/CM•Sends the four-wheel speed and DSC operating condition signals, as CAN signals, to the
4WD CM.
•Sends the coupling torque request signal, as a CAN signal, to the 4WD CM.
KO
P I
A
C
NH G
9
8
7
5
4
3
10
13
11
12
6
1
2
A6E63222002
1 Battery
2 Ignition switch
3 Differential oil temperature sensor
4 4WD control modure (4WD CM)
5 Electronic control coupling
6 4WD solenoid
7 Instrument cluster8 DSC HU/CM
9TCM
10 PCM
11 CAN-H
12 CAN-L
13 CAN driver

M–12
ELECTRONIC 4WD CONTROL SYSTEM
DIFFERENTIAL OIL TEMPERATURE SENSORA6E632227100203Function
•The differential oil temperature sensor detects the rear differential oil temperature based on the resistance of
the thermistor, and inputs it to the 4WD control modure (4WD CM).
Construction/Operation
•The differential oil temperature sensor is installed in the rear differential carrier.
•The differential oil temperature sensor uses a thermistor whose resistance changes according to changes in
the rear differential oil temperature.
•The resistance grows smaller as the oil temperature rises and vice-versa, as shown.
.
End Of Sie
4WD WARNING LIGHTA6E632227100204Construction
•The 4WD warning light is built into the instrument cluster.
•If the self-diagnostic function stores a DTC, the warning light illuminates to alert the driver of the malfunction. If
system control is temporarily suspended due to the rear differential oil temperature becoming abnormally hot or
similar cause, the warning light flashes to alert the driver.
•The 4WD CM controls the operation of the warning light.
.
End Of Sie
5
4
3
1
2
A6E63222006
1 Differential oil temperature sensor characteristic
2 Resistance (ohm)
3 Temperature (°C {°F})4 Larger
5 Higher
1
A6E63222007
1 4WD warning light

M–14
ELECTRONIC 4WD CONTROL SYSTEM
End Of Sie4WD SYSTEM CONTROLA6E632227100206Outline
Features
•Based on the inputted signals listed below, the 4WD CM calculates the optimal amount of torque distribution for
the rear wheels and outputs a corresponding electric control current to the electronic control coupling (4WD
solenoid).
•The module controls the current outputted to the 4WD solenoid by changing the rate of the ON/OFF timing.
Construction
Block diagram
.
Signal output part Signal name Note
PCMThrottle opening angle
Engine speed
Transmitted as a CAN signal TCMSelector lever position
Gear position
DSC HU/CMFour-wheel speed
DSC operating condition
Coupling torque request (DSC equipped vehicles)
Differential oil temperature
sensorRear differential oil temperature—
9
87
5
4
310
1413
11
12
61
2
A6E63222009
1PCM
2TCM
3 DSC HU/CM
4 Differential oil temperature sensor
5 Throttle opening angle
6 Engine speed
7 Selector lever position8 Gear position
9 Four-wheel speed
10 DSC operating condition
11 Coupling torque request (DSC equipped vehicles)
12 Rear differential oil temperature
13 4WD control modure (4WD CM)
14 Electronic control coupling (4WD solenoid)

M–16
ELECTRONIC 4WD CONTROL SYSTEM
ON-BOARD DIAGNOSTICA6E632227100208Outline
•The on-board diagnostic function allows for detecting malfunctions in the input/output signals when the ignition
key is at the ON position.
•The DLC-2, which combines the failure detection and detection maintenance connectors, has been adopted to
improve serviceability. By connecting a WDS or equivalent to the DLC-2, malfunction diagnosis can be carried
out.
•Using a WDS or equivalent DTCs can be retrieved or erased, depending on the screen display, thus improving
serviceability.
Block diagram
.
Self-diagnostic function
Failure detection function
•The failure detection function detects malfunctions in the input/output signal systems of the 4WD CM and
displays them when the ignition key is at the ON position.
•When the ignition key is turned to the ON position, the 4WD CM system begins operation, and the 4WD
warning light illuminates for 3 seconds while the function checks for open circuits. At the same time the function
monitors the condition of the power supply voltage and checks for internal malfunctions.
•Then, once the system is running, the function checks the operating conditions of the 4WD solenoid and the
differential oil temperature sensor at regular intervals to determine whether there is any malfunction.
•If any malfunction is detected during these diagnostic tests, the warning light illuminates according to the
malfunction to alert the driver. Also, a DTC is output to DLC-2 via the CAN line. Also, at the same time the
failure detection result is sent to the memory and fail-safe functions.
9
87
5
4
3
10
13
11
12
6
12
A6E63222010
1 Input part
2 Regular control area
3 Output part
4 Fail-safe function
5 Failure detection function
6 Memory function
7 Failure display function8 External tester communication function
9 Failure diagnosis function
10 4WD warning light
11 DLC-2
12 CAN
13 WDS or equivalent

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.
End Of Sie
OUTLINE

M–20
LOCATION INDEX
REAR DIFFERENTIAL/ELECTRONIC 4WD CONTROL SYSTEM LOCATION INDEXA6E630027100201
.
End Of Sie
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)

M–22
REAR AXLE
WHEEL HUB BOLT REPLACEMENTA6E6314050002011. Remove the brake caliper component and the disc plate.
2. Remove the wheel hub bolt using the SST as
shown in the figure.
Note
•If the dust cover interferes with the wheel
hub bolt and the wheel hub bolt cannot be
removed, tap the part shown in the figure
with a chisel lightly and bend the process
back to the knuckle side.
3. Install a new wheel hub bolt into the wheel hub
and install a washer and hub nut on the hub bolt.
4. Tighten the hub nut while holding the wheel hub
using a brass bar.
End Of Sie
WHEEL HUB, KNUCKLE REMOVAL/INSTALLATIONA6E631405000202
Caution
•Performing the following procedures without first removing the ABS wheel-speed sensor may
possibly cause an open circuit in the harness if it is pulled by mistake. Before performing the
following procedures, remove the ABS wheel-speed sensor (wheel side) and fix it to an
appropriate place where the sensor will not be pulled by mistake while the vehicle is being
serviced.
1. Remove in the order indicated in the table.
2. Install in the reverse order of removal.
REAR AXLE
49 T028 3A0
BEND THIS PART
A6E0311W011
HUB BOLT
WHEEL
NUT WHEEL
NUT
WASHER
BRASS
BAR
A6E0311W012

REAR AXLE
M–23
M
.
93.2—131.4
{9.6—13.3,
68.8—96.9}
HHG
G
E
E
F
F
AB
A
B
C
C
D
D
86.2—116.6
{8.8—11.9, 63.6—85.9} 18.6—25.5
{1.90—2.63,
13.8—18.8}75.5—94.5
{7.7—9.6, 55.7—69.6}51.0—66.7
{5.3—6.8,
37.7—49.1}43.1—60.8
{4.4—6.1, 31.8—44.8}
235.2—318.5
{24.0—32.4,
173.5—234.9}
9
8
7
5
4
3
1
2
10
1918
17
15
16
14
13
11
12
20
6SST
SST
R
SST
R
R
R
R
75.5—94.5
{7.7—9.6,
55.7—69.6}
86.2—116.6
{8.8—11.9, 63.6—85.9}
86.2—116.6
{8.8—11.9, 63.6—85.9}
N·m {kgf·m, ft·lbf}
A6E63142101
1 ABS wheel-speed sensor
2 Parking brake cable
3 Locknut
(See M–24 Locknut Removal Note)
(See M–28 Locknut Installation Note)
4 Brake caliper component
5 Disc plate
6 Bolt (stabilizer control link (lower))
7 Bolt (rear lower arm (outer))
(See M–24 Bolt (Rear Lower Arm (Outer)) Removal
Note
8 Rear coil spring
(See M–28 Rear Coil Spring Installation Note)
9 Bolt (rear upper arm (outer))
10 Bolt (shock absorber (lower))
(See M–24 Bolt (Shock Absorber (Lower)) Removal
Note)11 Bolt (lateral link (outer))
(See M–24 Bolt (Lateral Link (Outer)) Removal
Note)
12 Bolt (trailing link (front))
(See M–25 Bolt (Trailing Link (Front)) Removal
Note)
(See M–28 Bolt (Trailing Link (Front)) Installation
Note)
13 Trailing link, knuckle component
14 Wheel hub, knuckle component
15 Wheel hub
(See M–25 Wheel Hub Removal Note)
(See M–27 Wheel Hub Installation Note)
16 Snap ring
17 Wheel bearing
(See M–25 Wheel Bearing Removal Note)
(See M–27 Wheel Bearing Installation Note)