Downloaded from www.Manualslib.com manuals search engine 109Brake System
3. Installing the ABS rear wheel speed sensor with brack-
et assembly.
Use three hexagon head bolts, spring washers, and flat
washer subassembly connecting pieces to connect the sensor
to the rear hub unit, rear twist beam, and vehicle body.
ABS General Problem Maintenance and Areas of Importance
Common problems and solutions
1. When braking, the ABS hydraulic pressure unit noise is overly loud.
When the ABS is working, the motor inside the hydraulic pressure unit is ceaselessly rotating. At this time the
driver can feel the brake pedal bouncing back. However, this bounce back feeling will be entirely different
depending on the speed and road condition. Also, when performing an actuator movement test, the sound of the
running motor may also be sensed. When the vehicle is being driven and the brake is off, the sound of the motor
running can still occasionally be heard. This is the ABS undergoing component inspection, not a malfunction.
If the ABS hydraulic pressure unit noise is irregular, a movement test can be initiated. Compare the noise to that
of normal vehicles to determine if ABS hydraulic pressure unit noise is abnormal.
2. Inlet and outlet solenoid valve failure.
Once the ignition switch is ON, the ABS control unit automatically initiates a self-check. If an inlet and outlet solenoid
valve short circuit or open circuit is found, it will record the failure, light up the fault light, and abort the operation. If using a
scanner to adjust the problem code, make sure to use the movement test t\
o confirm that the solenoid valve has a problem and
then replace the hydraulic pressure unit directly.
X431 data flow: While the ABS is functioning, the inlet and outlet solenoid valves rapidly change operating
conditions.
EVFL - Front inlet valve LHOff / On
AVFL - Front outlet valve LHOff / On
EVFR - Front outlet valve RHOff / On
AVFR - Rront outlet valve RHOff / On
EVRR - Rear inlet valve LHOff / On
AVRR - Rear outlet valve LHOff / On
EVRR - Rear inlet valve RHOff / On
AVRR - Rear outlet valve RHOff / On
3. Wheel speed sensor malfunction.
With the engine running, use a oscilloscope to measure the voltage between the sensor's signal line and the
ground.
Output signal when wheel is stationary:
Output signal when the wheels are rotating: signal type is 0.44 V and 1.26 V square wave signal, duty cycle: 50: 50.
Rear hub unit assembly
Rear wheel speed sensor with bracket assembly
Hexagon head bolt, spring washer, and flat washer subassembly
Hexagon head bolt, spring washer, and flat washer subassembly
0
v
t
vv
0 0
tt
or
Downloaded from www.Manualslib.com manuals search engine GWFLORID Maintenance Manual110
The X431 scanner possesses a waveform function. Wheel speed signal error (wheel speed sensor failure)
only appears when intermittent problems occure, such as high speed. When in use, some signal errors may
occasionally appear. Continue observing the waveform to make sure there is nothing abnormal.When driving
the vehicle on a flat and straight road, all four wheels' speed sensor waveform are extremely similar. One can
compare the two front wheels' with the two rear wheels' signal wave at t\
he same time.
Mechanical causes:
Signal gear distortion, loosened hub bearings, smudges on the sensor surface, etc, all may lead to wheel speed
signal intermittency and inaccuracy. Failure examples:
As shown above, once the intermittent failures with the wheel's speed sensor signal are detected, the ABS
control unit records the sensor problems and lights up the warning lamp.\
4. Wheel speed sensor velocity failure (ECU detects an excessive difference between the two wheels'
speed sensor signals).
Possible causes are the gear's wheel speed sensor gap is overly large, or the wheel speed sensor signal is
experiencing interference. For this, first determine which sensor is emitting the signal, and then use failure
three's maintenance methods.
Areas of Importance
1. Sometimes, in order to determine whether there is a common brake system problem or an ABS
problem, the ABS must be terminated by pulling out its ABSECU connector or fuse. At this time the
ABS/EBD loses function as well. On muddy, icy, or snowy roads, the vehicle may fishtail or slide, in
which cases one must be extremely careful to avoid hard braking.
2. The ABS malfunction rate is extremely low, when the brake system shows any problem (before the
warning lamp goes on), first eliminate the normal brake system problems, then consider the ABS mal-
functions.
3. When raining or on gravel, this adjusting process is longer than the standard process, because this
kind of road's unstable adhesion coefficient will lead to a difference between the sliding measurement
and calculation procedures, thus it is necessary to remind drivers to be especially careful when driving
under the circumstances mentioned above.
4. ABSECU Areas of Importance:
(a) The ABSECU is easily damaged from impacts or collisions, thus pay attention to ensure the ECU avoids
such incidents.
(b) High temperature environments can also easily damage the ECU, so when the vehicle undergoes hot paint
work, make sure to first take the ECU out of the vehicle.
(c) When the power switch is ON, do not disassemble the system's electrical elements and wire harness plugs,
in order to avoid damage to the ECU. If removal or installation must be carried out, be sure to disconnect
the ignition switch firstly. When welding components or circuits to the system, the wire harness plug
V( Km/h)
60
30
Signal interrupt
t
Downloaded from www.Manualslib.com manuals search engine GWFLORID Maintenance Manual144
Double-colored wire: Primary color is Red, secondary color is Blue, mark\
ed as RBl.
0.5BrGr means Brown wire with a Gray fine wire, and sectional area is 0.\
5 mm2.
Areas of importance in circuit maintenance
1. Before operating any electronic devices, and when tools or maintenance devices may easily make
contact with an uncovered electronic terminal, please make sure to turn the ignition switch to the LOCK
position, and then disconnect the battery's negative cable to avoid injury or vehicle damage. When the
ignition switch is on the ON position, please do not disconnect the battery's connecting wire or take out
the power's fuse, regardless if the engine is running or not.Otherwise it would seriously damage the
ECU and related microelectronic devices such as sensors.
2. When changing the fuse, please make sure that the new fuse possesses the proper current rating,
and is not above or below this rating.
3. When repairing the wire harnesses of the airbag and pretensioner, only specified contact points,
plugs, and wires are allowed to be used.
4. Before repairing the wire harness, make sure to eliminate any factor that might cause damage,
for example, the edge of a vehicle body part is too sharp, or the used electronics are damaged or
corroded.
5. Shielded wire should not be repaired, it must be replaced entirely once it is damaged.
6. Unless it is specified during the test, please do not use an analog multimeter to test the ECU and
sensor, instead use a high-impedance digital multimeter (internal resistance should be ≥10 kΩ) or a
vehicle multimeter for inspection.
7. When inspecting the connector with a digital multimeter, take the waterproof rubber cover off the
connector, and tightly insert the test pen along the connecting terminal. Don't use too much force, as
to avoid cracking the connector.
Circuit inspection steps
The principle of troubleshooting is to confirm the "possible cause". Once the possible cause is confirmed, the
components that need to be inspected are limited to the components that are related to the possible cause. The
confirmed possible cause should be based on theory and be supported by facts, but not just by intuition. If
one tries to solve the problem but does not adopt the proper troubleshooting steps, it may make the problem
worse. Then the possible cause not only can't be confirmed, but also maintenance can't be performed properly.
Troubleshooting should adhere to the four steps below:
1. Observe the symptoms carefully, inspect if there is anything else abnormal, and record it.
2. While confirming the possible causes, study the circuit diagram carefully, and regard it as a whole
system in order to understand the circuit. Thorough knowledge of switches, relays, and other
electronic components is obligatory for proper analysis.
3. Inspect and eliminate the problems one by one until the cause is found.
4. After the malfunction is fixed, make sure to check if the inspected system is working properly, and also
check if the maintenance may have caused any new problems.
Compres-
sor relay
Reserve
Sunroof (Elite) Lamplet
Reserve
Reserve
Reserve
Reserve Door and window Reserve Blower
Lamplet
relay Flasher relay Blower high
speed relay (Elite) Door and
window relay (Comfort, Luxury) Blower relay
Reserve
Front fog lamp
Combination
meter
Interior
lighting
central
door lock
brake lamp
CD player
Reserve
Reserve
Reserve
Cigarette
lighter
Rearview
mirror
Front wiper
Charge
Airbag
Reserve
Reverse lamp Rear fog lamp
Rear wiper
Defroster Compressor
ACC relay
IG relayRear wiper
relay Defroster
relay
Front fog
lamp relay Rear fog
lamp relay
Warning lamp
Turn signal lamp
Cab No.1 fuse box
Fuse Box
Downloaded from www.Manualslib.com manuals search engine 145Vehicle Body Electronic System
Fuse numberCurrent ratingFuse typePowerBearer circuit
F01Reserve
AutoFuse
30 Battery (+)
F0225 ASunroof (Elite)
F0310 AParking lamp relay, front fog lamp
switch, rear fog lamp switch
F0415 A
F05Reserve
F0615 AHazard warning lamp
F0710 A15a IG1 Turn signal lamp
F0815 A
30 Battery (+)
Front fog lamp relay
F0910 ARear fog lamp relay
F1010 ACompressor relay
F1110 ARear wiper relay
F1225 ARear defroster, rearview mirror defroster
F1310 ACombination meter
F1410 AInternal lighting
F1520 ACentral lock controller
F1610 ABrake lamp switch
F1715 AStereo
F18Reserve
F19Reserve
F20Reserve
F2125 AX Attached
ACC
Front cigarette lighter, rear cigarette
lighter, backup power supply
F2215 APower rearview mirror
F2315 A
15a IG1
Front wiper motor, front and rear washer motor
F2410 ACombination meter indicator lamp power
F2510 AABS ECU
F2615 AAirbag
F27Reserve
F2810 AReverse lamp, air conditioner controller
S/B1Reserve
Slow burn fuse 30 Battery (+)
S/B230 ADoor and window relay (Non Jam Protection)
S/B3Reserve
S/B440 ABlower relay
S/B5Reserve
Fuse number and bearer circuit
Downloaded from www.Manualslib.com manuals search engine 153Vehicle Body Electronic System
High mounted brake lamp
Rear defroster positiveRear wiper motor
Trunk lock motor, door lamp switch
Opener switchRear defroster negative
Theft deterrent indicator lampCombination meter CD/DVD
Air conditioner speed adjuster, AC switch, rear defroster switch
Air conditioner temperature sensorF r o n t P a s s e n g e r s i d e airbag assembly
BlowerGlove box lighting
Cigarette lighter and lighting
Airbag ECU assembly 2
Diagnostic port
Acceleration pedal
Power rearview mirror switch, light brightness regulator
Trunk door wire harness
Central lock controller
Dashboard wire harness
Downloaded from www.Manualslib.com manuals search engine GWFLORID Maintenance Manual154
Door lock motorDoor and window main switchesMiddle & low tone speaker
High tone speaker
Outer power rearview mirror
Window regulator motor
Door lock motor
Wi n d o w r e g u l a t o r switch
Window regulator motorMiddle & low tone speaker
Fog lampLicense plate lamp
Rear
combination lamp LH
Rear combination lamp RH
Rear wheel speed sensor RHParking brake switch
Front door light switch LH
Seat belt pretensioner
Rear wheel speed sensor LH
Rear door light switch LH
Backup power supply
Front & rear door wire harnesses
Vehicle body wire harness
Front doorRear door
Reverse sensor ECU
Reverse sensor probeOil pump motor
Downloaded from www.Manualslib.com manuals search engine 155Vehicle Body Electronic System
Condenser fan motor
Connected compressor
Oil pressure switch
Front oxygen sensor
Connected reverse switch
Connected engine speed sensor Connected
ignition coil
Connected speed sensor Connected coolant temp. sensor
Canister control valve
Connected combination meter A
Connected antenna
Diagnostic port
Connected AC switch Connected air conditioner temperature sensor
Front passenger side airbag
Connected speed adjustive resistance, blower
Front window regulator RH
Front window regulator switch RH
Front medium woofer RH
Front tweeter LH Right outer electric mirror
Front passenger side central door lock switch
Front door lamp switch RH
Front passenger seat belt pretensioner Front door lock motor RH
Ground
plate 3
Connected cigarette lighter (lighting)
Connected cigarette lighter
Front passenger seat belt switch
Connected parking brake switch Connected air conditioner governor & front
passenger seat belt unfastened indicator lamp
Connected CD player
Connected engine ECUConnected ground P1#
Connected ground P2#
Connected starter
Connected knock sensor
Connected starter field coil
Connected inlet
temperature pressure
sensor
connected
electronic throttle
Rear oxygen sensor
Connected 4th
cylinder injection
nozzle
Connected 3rd
cylinder injection
nozzle
Connected 2nd
cylinder injection
nozzle
Connected 1st
cylinder
injection nozzle
Connected generator
Connected engine armature Connected front combination lamp RH
Connected front fog lamp RH
Connected rear washer motor
Connected front washer motor
Connected front wheel speed sensor RH
Right ground
Connected A/C pressure switch
Connected phase sensor
Connected low
pitched horn
Connected front
combination lamp LH
Rediator fan motor
Connected front
fog lamp LH
Connected high pitched horn
Battery
negative
Body
ground
Battery
Left ground Connected
brake lamp
switch Connected brake fluid warning switch
Connected theft deterrent indicator Theft deterrent ECU 1Connected lock
cylinder lightConnected ignition
switch (white)
The key is inserted into the switch
Right combination switch (wiper) Connected airbag ECU (yellow)Ground
plate 2
Ground
plate 4
Connected accelerator pedal
Ground plate 1
Left outer electric mirror
Front medium woofer LH Front door lock motor LH
Rear medium woofer LH
Rear window regulator switch LH
Rear door lock motor LH Rear door lamp switch LH
Ground point ACapacitor
Vehicle power supply
Rear fog lamp LH Left license plate lamp
High mounted brake lamp
Ground point Trunk opener switch
Trunk motorRear wiper motor
Rear windshield defroster “-”
Trunk lamp switch Right license plate lamp
Rear fog lamp RH
Rear combination lamp RHRear wheel speed sensor RH
Rear window
regulator RH
Rear window
regulator switch RH
Rear door lock motor RH
Rear door lamp switch RH Rear medium woofer RH
Ground point B
Rear combination lamp LH
Rear windshield defroster “+”
Rear wheel speed
sensor LH
Rear window regulator LH
Fuel pump, fuel sensor
Rear interior dome lamp
Front door lamp
switch LH
Driver seat belt pretensioner Driver seat belt switch
Front tweeter LH
Connected light brightness regulator switch
Connected rearview mirror switch (white)
Connected glove box lamp
Front window regulator LH Left combination switch (light)
Connected main airbag, horn switch
Window regulator mainly
control switch, central door
lock mainly control switch Connected central door lock controller (white)
Connected front wiper motor
Connected clutch
switch
Connected ABS ECUBattery
positive
Connected front wheel
speed sensor LH Engine groud
Starter connect to
battery positive
Generator connect to
battery positive
Wire Harness Relationship and Plug-in Connections Numbered Diagram
Downloaded from www.Manualslib.com manuals search engine 169Vehicle Body Electronic System
Combination meter system
Connected engine ECU #8
Connected engine ECU #59
To light brightness
regulator switch
Parking brake lamp
Parking brake switch
Brake fluid level switch
Oil pressure switch
Driver seat belt switch
Fuel sensor
Speed sensor
Connected combination meter A
Driver seat belt switch Connected parking brake switch Fuel pump, fuel sensor Coolant temperature sensor Engine speed sensor
Speed sensor Connected combination meter B
Brake fluid level warning switch
Brake warning lamp
Low oil pressure indicator
Seat belt unfastened indicator
Low fuel alarm Fuel gauge
High water temperature alarm
Low water temperature alarm
Connected coolant
temperature sensor Connected central
control ECU #18
IC module
LCD display
Odometer
Tachometer