GEELY CK 2008 Workshop Manual

284Note: This fault only applies to the condition that the system can communicate with the scan
meter (ABS ECU Power supply is normal), and there is no DTC set. 2 Afte r the e ngine is s tarte d, AB S
Warning Light is normally onLik e ly Caus e s
[De s cription]
One of the Likely Ca use s is tha t
ABS warning light drive module is da mage d or
there is a n ope n in the ABS wa rning light
circuit.z The warning light drive module is da mage d
z A B S w a r ning light dr ive module c ir c uit ope n
z ABS ECU is damagedRepair the wire harnessCheck whether there is an open circuit in the wire be-
tween the ECU and ABS warning light drive module Check the ABS warning light drive moduleReplace Abn. No Ye s Replace the ABS ECUOk

285 3 Abno rmal AB S o pe ratio n Lik e ly Caus e s
[De s cription]
It is in c lose c onne ction with the
driver status and the road conditions and is
difficult to dia gnose. Howeve r, if there is no
DTC me mory, the following inspec tions c an be
performed.z Imprope rly ins ta lle d s e ns or
z Sensor wire ha rness faulty
z Da ma ge d se nsor
z Da ma ge d ring ge a r
z Foreign obje cts in the se nsor
z Damaged wheel bearing
z Damaged ABS HCU
z Damaged ABS ECUIs the sensor installed correctlyCheck the sensor output volt-
age Check each sensorCheck each sensor ring gearCheck the wheel bearing clearance Check the ABS ECU socket and
the middle connectorNo
Installed it correctly
Abn.
Abn.
Abn.
Abn. Ok
Ye s
No
Ok
OkReplace
Replace
Repair
the connectorUse scan meter for HCU di-
agnosis Ye s Does the fault reoccur? Ye s
NoRefer to
"Occasional
Problem
Service Key
Points"Replace the ABS HCURemove the ABS ECU connector,
check whether the resistances
among the following terminals are
within specification?
Standard: 1.0~1.3K¸
Shake the sensor wire harness and
connector while measuring them
LF: 1-2
RF: 19-20
LR: 5-6
RR: 22-23Abn.
Replace
or Repair Ye s
OkRepair the
wire har-
ness or
connectoReplace the ABS HCUAbn.

286 4 Exce s s ive ly long brak e pe dal s trok e Lik e ly Caus e s
[De s cription]
Visually inspect whether there
is leakage or mechanical fault. Use bleeding
method to check whether there is air in the
system. Use the HCU function of the scan
meter to test whether the normally-closed valve
is le a king.z Brake fluid leakage
z Air in the system
z Brake disc severely worn
z B r a ke f luid le ve l s w it c h f a ult yTighten the pipe connector as
specifiedVisually inspect whether the hydraulic pipe connector is
leaking Check the brake disc wearReplace the brake disc Abn. Ok Abn. Check the brake fluid level switchOk Bleed and checkOk Use the scan meter HCU to diagnose and check the nor-
mally-closed valve sealOkReplace the brake fluid level
switch Abn.Re-bleed the system Abn.Replace the HCU Abn.

287 5 The Pe dal mus t be de pre s s e d he av ily Lik e ly Caus e s[De s cription]
U s e t r a dit iona l me t hod t o c he c k
the booste r a nd the bra ke pe da l stroke . Sc an
meter HCU function can be used to check the
fa ult of the norma lly-ope n va lvez Boost fa ulty
z Normally-close valve faultyReplace the HCUUse Scan meter HCU function can be used to check the
normally-open valve Check the booster and the pedal stroke with Non-ABS tra-
ditional methodOkAbn.

288 6 No DTC output
（can no t
communicate with the s can me te r
）Lik e ly Caus e s
[De s cription]
It ma y be the ABS ECU powe r
supply c ircuit or dia gnosis wire circ uit tha t c an
not communicate with the scan meterz Burned fuse
z Diagnosis wire broke n or connec tor disc onne c ted
z Damaged ABS ECU
z Scan meter faultyCan the scan meter commu-
nicate with the MK-20 ABS
ECU on other vehicles? ABS scan meter faulty, check it af-
ter repairing itReplaceCheck the power cable, ground wire
and diagnostic wire in the diagnos-
tic interface Check the diagnostic interface or wire harness No
Ye s
No
Ye s
ContinuityCheck ABS power supply
fuse OkReplace the ABS ECURepair the
diagnostic
interface or
harnessIs there any scan meterAbn.Remove the ABS ECU
connector, check whether
there is continuity between
terminal 7 in the ABS wire
harness and the terminal 8 in
the diagnostic interfaceAbn.NoNo

289III. ABS System CheckIte mIgnition
Switch ShiftTe rminal Pole Standard Unit
Battery Voltage OFF 25-8 10.1～
14.5 V
Battery Voltage
（
s ole noid va lve）OFF 9-24 10.1～
14.5 V
P owe r supply
in s ula t ionOFF 8-4 0.00～
0.5 V
Ground insula tion OFF 8-24 0.00～
0.5 V
P owe r supply
volta geON 8-4 10.1～
14.5 V
OFF Warning light goe s off Visua l inspec tion
ON Wa rning light goes on Visua l inspec tion
OFF Warning light goe s off Visua l inspec tion
ONWa rning light goes on
for a bout 1.7 se c onds
then goes offVisual inspection
B r a ke light s w it c h
peda l not de presse dON 8-18 0. 0～
0.5 V
B r a ke light s w it c h
peda l de pre sse dON 8-18 10. 0～
14.5 V
Diagnostic interface OFFDia gnostic inte rfa c e
K & 70.0～
0.5Ω
LF Wheel Speed
Sensor ResistanceOFF 1-20 1.2～
1.3 KΩ
RF Wheel Speed
Sensor ResistanceOFF 19-20 1.2～
1.3 KΩ
LR Wheel Speed
Sensor ResistanceOFF 5-6 1.0～
1.3 KΩ
RR Wheel Speed
Sensor ResistanceOFF 22-23 1.0～
1.3 KΩ
LF Whe e l Se nsor
Output VoltageOFF 1-2 3.4～
14.8 MV/Hz
RF Whe e l Se nsor
Output VoltageOFF 19-20 3.4～
14.8 MV/Hz
LR Whe e l Se nsor
Output VoltageOFF 5-6 >12.2 MV/Hz
RR Wheel Sensor
Output VoltageOFF 22-23 >12.2 MV/Hz
Spee d Se nsor Output
Voltage RatioABS Warning LightECU not connected
Connect ECUMaximum peak voltage
Minimum peak voltage≦2

290Note: This inspection uses the "03 HCU diagnosis" of the Scan Meter.Ite m Ke y Switch Actio n Standard No te s
ON Depress the pedalWhen LF wheel can not
rotate, the pedal does
not de sce ndNormally-closed
valve inspection
ON（
two va lve s
a nd pumps a re
energized
simultaneously）Depress the pedalLF wheel can rotate
free ly, the pe da l doe s
not de sce ndNormally-open
va lve ins pe c t ion
ON Depress the pedalWhen RF wheel can not
rotate, the pedal does
not de sce ndNormally-closed
valve inspection
ON（
two va lve s
a nd pumps a re
energized
simultaneously）Depress the pedalRF wheel can rotate
free ly, the pe da l doe s
not de sce ndNormally-open
va lve ins pe c t ion
ON Depress the pedalWhen LR wheel can not
rotate, the pedal does
not de sce ndNormally-closed
valve inspection
ON（
two va lve s
a nd pumps a re
energized
s imult a ne ous ly
）Depress the pedalLR wheel can rotate
free ly, the pe da l doe s
not de sce ndNormally-open
va lve ins pe c t ion
ON Depress the pedalWhen RR wheel can
not rota te, the pe dal
does not de sc e ndNormally-closed
valve inspection
ON（
two va lve s
a nd pumps a re
energized
simultaneously）Depress the pedalRR wheel can rotate
free ly, the pe da l doe s
not de sce ndNormally-open
va lve ins pe c t ion RR wheel
norma lly-ope n
and closed valves
seal performance No te : The v acuum bo o s te r mus t hav e v acuum applie d whe n pe rfo rming the fo llo wing
ins pe ction.
LF Wheel
norma lly-ope n
and closed valves
seal performance
RF wheel
norma lly-ope n
and closed valves
seal performance
LR wheel
norma lly-ope n
and closed valves
seal performance

291IV. ABS Operation Inspection1. Check the Wheel Speed Sensor Output Voltage
1Check whether the clearance between the wheel speed sensor and the ring gear is within the specification
For front wheel standard value, refer to "Front Wheel Sensor Installation Drawing"
For rear wheel standard value, refer to "Rear Wheel Sensor Installation Drawing"
3Jack up the wheel and release the manual brake
2Remove the ABS wire harness, measure at the wire harness connector
4Rotate the wheel at the speed of 1/2 turn/second, and use the multimeter or oscilloscope to measure the
output voltage
Terminal 1-2
Terminal 19-20
Terminal 5-6
Terminal 22-23
Output Voltage
zWhen use the multimeter to measure
For front wheel, refer to "Front Wheel Sensor Drawing".
For rear wheel, refer to "Rear Wheel Sensor Drawing".
zWhen use the oscilloscope to measure
For front wheel, refer to the related standard.
For rear wheel, refer to the related standard.
5The fact that the output voltage is not within the above range may result from the following causes:
zExcessive clearance between the sensor and the ring gear.
zSensor fault.
zCheck the sensor resistance£¨1.0 - 1.3k¦¸£©.
zSelect the 4 points on the ring gear to check the clearance (ring gear distortion) between the ring
gear and the wheel speed sensor.
2.Check the Hydraulic Control Unit (HCU).
1Jack up the vehicle, make sure the wheel can rotate freely.
2Release the manual brake.
3Turn the ignition switch to ON after connecting the scan meter, do not start the engine this time.
4Refer to the HCU Diagnosis for inspection.
Note: when connecting or removing the scan meter, the ignition switch must be turned to OFF.

292Section 3 Removal and InstallationI.Precautions for Removal1. Use the scan meter to locate the fault causes before proceeding to service.
2. wipe the surface clean with the cleaning agent without mineral oil before service; be careful to keep it
clean during service, only the lint-free cloth can be used to wipe the removed parts.
3. Only the original spare part can be used, and the package of the new spare part shall not be removed until
the installation.
4. Return liquid pump motor and the HCU is a type of integral structure and can not be separated.
5. When the system is opened, do not use compressed air or move the vehicle.
6. Use proper plug to clog each hydraulic outlet as soon as the ABS assembly is removed.
7. Remove other components that may interfere.
8. Please use the DOT 4 brake fluid, do not use the mineral oil.
9. Use the brake fluid to immerse the seal and the O ring, do not use the engine oil or brake grease.
10. After service, check the regular brake system and ABS brake function for normal and reliable operation.
11. Check all hydraulic pipe union for leakage.II. HECU Removal1. Turn off the ignition switch and disconnect the battery negative ground cable.
2. Remove the wire connector from the ABS HECU assembly.
3. Depress the brake pedal >60mm and hold it with the pedal retainer to close the master cylinder center
valve so that the brake fluid will not flow out from the outlet when the system is opened.
4. Put a clean cushion under the hydraulic regulator.
5. Remove the brake pipe (A, B) on the HCU connected to the master cylinder and place the mark, then
use a plug to clog the outlet immediately.
6. Remove the brake fluid pipe(1-4) leading to the wheels, then use a plug to clog the outlet immediately.
7. Remove the nut attaching the HECU to the bracket.

2938. Remove the whole HECU from the bracket.
ABS HECU Assembly
ABS HECU Brake Pipe Removal Schematic