brake light OPEL FRONTERA 1998 User Guide

5A–6
BRAKE CONTROL SYSTEM
Test Driving ABS Complaint Vehicles
In case that there has been an malfunction in the lighting
pattern of “ABS” warning light, the fault can be located in
accordance with the “DIAGNOSIS BY “ABS” WARNING
LIGHT ILLUMINATION PATTERN” . In case of such
trouble as can be detected by the driver as a vehicle
symptom, however, it is necessary to give a test drive
following the test procedure mentioned below, thereby
reproducing the symptom for trouble diagnosis on a
symptom basis:
1. Start the engine and make sure that the “ABS” W/L
goes OFF. If the W/L remains ON, it means that the
Diagnostic Trouble Code (DTC) is stored. Therefore,
read the code and locate the fault.
2. Start the vehicle and accelerate to about 30 km/h (19
mph) or more.
3. Slowly brake and stop the vehicle completely.
4. Then restart the vehicle and accelerate to about 40
km/h (25 mph) or more.
5. Brake at a time so as to actuate the ABS and stop the
vehicle.
6. Be cautious of abnormality during the test. If the W/L
is actuated while driving, read the DTC and locate the
fault.
7. If the abnormality is not reproduced by the test, make
best efforts to reproduce the situation reported by the
customer.
8. If the abnormality has been detected, repair in
accordance with the “SYMPTOM DIAGNOSIS” .NOTE:Be sure to give a test drive on a wide, even road with
little traffic.
If an abnormality is detected, be sure to suspend the
test and start trouble diagnosis at once.
“ABS” Warning Light
When ABS trouble occurs and actuates when possible
the “ABS” warning light, the trouble code corresponding
to the trouble is stored in the EHCU. Only the ordinary
brake system is available when the ABS is turned off.
When the “ABS” warning light is actuated, if the starter
switch is set ON after setting it OFF once, the EHCU
checks up on the entire system and, if there is no
abnormality, judges ABS to work currently and the
warning light works normally even though the trouble
code is stored.
NOTE: Illumination of the “ABS” warning light indicates
that anti-lock braking is no longer available. Power
assisted braking without anti-lock control is still available.
Normal Operation
“ABS” Warning Light
W h e n t h e i g n i t i o n i s f i r s t m o v e d f r o m “ O F F ” t o “ R U N ” , t h e
amber “ABS” warning light will turn “ON” . The “ABS”
warning light will turn “ON” during engine starting and will
usually stay “ON” for approximately three seconds after
the ignition switch is returned to the “ON” position. The
warning light should remain “OFF” at all other times.
Basic Diagnostic Flow Chart
StepActionYe sNo
11. Customer complaint.
2. Questioning to customer.
3. Basic inspection (Refer to “Basic inspection procedure”)
Using TECH 2?
Go to Step 2Go to Step 4
2Make sure of DTC by mode “F0: Diagnostic Trouble Codes”.
Is EHCU including DTC?
Go to Step 3Go to Step 5
31. Repair of faulty part.
2. Elimination of DTC.
3. Inspection of “ABS” W/L Illumination pattern with ignition SW
“ON”.
4. Test drive.
Does repeat trouble?
Repeat the
diagnosis it the
symptom or DTC
appears again Go
to Step 1
Go to Step 5
4Check if the DTC is stored.
Is EHCU including DTC?
Go to Step 3
Trouble diagnosis
based on
symptom (Refer
to “SYMPTOM
DIAGNOSIS”) Go
to Step 3
51. Reconnect all components and ensure all component are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
FinishedGo to Step 5

5A–7 BRAKE CONTROL SYSTEM
Basic Inspection Procedure
1. Basic Inspection of System Brake
StepActionYe sNo
1Is the fluid level normal?
Go to Step 2
Replenish with
fluid.
Go to Step 2
2Does fluid leak?Repair.
Go to Step 3
Go to Step 3
3Is the booster functioning normal?
Go to Step 4
Repair.
Go to Step 4
4Is the pad and rotor normal?
Go to Step 5
Repair.
Go to Step 5
5Reconnect all components and ensure all component are
properly mounted.
Was this step finished?
FinishedGo to Step 5
2. Inspection of Front Axle Switch
StepActionYe sNo
1Turn the key switch on and shift the T/F to 4WD position.
Does the 4WD light come on?
Go to Step 2
Repair.
Go to Step 2
2Reconnect all components and ensure all components are
properly mounted.
Was this step finished?
FinishedGo to Step 2
3. Ground Inspection
StepActionYe sNo
1Are ABS—related ground points ok?
Go to Step 2
Repair.
Go to Step 2
2Reconnect all components and ensure all components are
properly mounted.
Was this step finished?
FinishedGo to Step 2

5A–11 BRAKE CONTROL SYSTEM
Data List
DisplayContentOK/NG Criteria for Data
Battery VoltageVo l t a g eBetween 10-16.9V
Brake Light SwitchOpen/CloseOpen(0V) when pedal is released
Closed(12V) when pedal is depressed.
Front Left Wheel Speed
Front Right Wheel Speed
Rear Left Wheel Speed
Rear Right Wheel SpeedMPH(km/h)Start the vehicle and make sure of linear change in each
wheel speed.
Turn each wheel by hand and make sure that each
speed data change.
Wheel Sensor StatusOK/NGTo be OK usually
G-sensorLow/HighTo be Low usually
Transfer Monitor(TOD)2 Wheel Drive
4 Wheel DriveWhen 2WD: 2 Wheel Drive
When 4WD: 4 Wheel Drive
Off-Road Switch
(Transmission Input)
Active/InactiveWhen shift lever position is 1, 2 and R: Active (M/T)
(Transmission Input)When shift lever position is L and R: Active (A/T)
Valve RelayActive/InactiveTo be Active usually
ABS StateON/OFFTo be OFF usually
ABS RelayActive/InactiveTo be Active usually
Return Pump RelayActive/InactiveTo be Inactive usually
Front Left Isolation ValveActive/InactiveTo be Inactive usually
Front Left Dump Valve
Front Right Isolation Valve
Front Right Dump Valve
Rear Isolation Valve
Rear Dump Valve
ABS Warning LampON/OFFTo be ON usually (while engine stopped)

5A–12
BRAKE CONTROL SYSTEM
EHCU Connector Pin-out Checks
Disconnect Electronic Brake Control Module.
Perform checks with high impedance digital
multimeter (5-8840-0366-0) or equivalent.
No.
Circuit to be TestedIgnition
Switch
PositionMultimeter
Scale/RangeMeasure
between
Pin NumberNominal ValueNote
1Ignition enableOFF20DCV8 (+), 15 (–)0V to 0.1V
ON20DCV8 (+), 15 (–)11.5V to 14.5V
2Stop light switchOFF20DCV10, 1510.5V to 14.5VPress brake pedal
3Ground connectionOFF20012, Ground
15, GroundLess than 2
4FL speed sensorOFF2k20, 211.3k to 1.9kInternal Resistance
OFF200k20, 15more than
100kInsulation Resistance
OFF200mACV20, 21more than
200mVTurn wheel at 1RPS
5FR speed sensorOFF2k4, 51.3k to 1.9kInternal Resistance
OFF200k4, 15more than
100kInsulation Resistance
OFF200mACV4, 5more than
200mVTurn wheel at 1RPS
6RL speed sensorOFF2k22, 231.3k to 1.9kInsulation Resistance
OFF200k22, 15more than
100kInternal Resistance
OFF200mACV22, 23more than
200mVTurn wheel at 1RPS
7RR speed sensorOFF2k2, 31.3k to 1.9kInternal Resistance
OFF200k2, 15more than
100kInsulation Resistance
OFF200mACV2, 3more than
200mVTurn wheel at 1RPS
8G-sensorON26,81k to 2kHorizontal vehicle
9Transmission InputON20DCV6 (+), 15 (–)Less than 6V
(Shift lever
position – L, R)
6.6 to 9.0V
(other shift
position)A/T
Battery voltage 12V
More than 9.6V
(Shift lever
position –
1, 2, R)
6.6 to 9.0V
(other shift
position)M/T
Battery voltage 12V

5A–35 BRAKE CONTROL SYSTEM
Symptom Diagnosis
The symptoms that cannot be indicated by the warning
light can be divided in the following five categories:
1. ABS works frequently but vehicle does not
decelerate.
2. Uneven braking occurs while ABS works.
3. The wheels lock during braking.4. Brake pedal feel is abnormal.
5. Braking sound (from EHCU) is heard while not
braking.
These are all attributable to problems which cannot be de-
tected by EHCU self-diagnosis. Use the customer com-
plaint and a test to determine which symptom is present.
Then follow the appropriate flow chart listed below.
NoSymptomDiagnostic Flow ChartsNo.Sym tomWithout TECH 2With TECH 2
1ABS works frequently but vehicle does not decelerate.Chart A–1Chart TA–1
2Uneven braking occurs while ABS works.Chart A–2—
3The wheels are locked.Chart A–3Chart TA–3
4Brake pedal feel is abnormal.Chart A–4—
5Braking sound (from EHCU) is heard while not braking. Chart A–5Chart TA–5
Chart A–1 ABS Works Frequently But Vehicle Does Not Decelerate
StepActionYe sNo
11. Turn key off.
2. G Sensor connector and EHCU connector disconnected.
Is there continuity between EHCU terminals 26 and 8?
Go to Step 2Go to Step 3
2Connect EHCU connector.
Is there continuity between the G sensor and the EHCU?
Go to Step 3
Repair circuit.
Go to Step 1
3Is the G sensor normal? (Refer to chart B-5)
Go to Step 4
Replace G
sensor.
Go to Step 11
4Is braking force distribution normal between the front and rear of
the vehicle?
Go to Step 5
Repair brake
parts.
Go to Step 11
5Are axle parts installed normally?Go to Step 6Repair axle parts.
Go to Step 11
6Is there play in each wheel speed sensor?Repair wheel
speed sensor.
Go to Step 11
Go to Step 7
7Is there damage, or powered iron sticking to each wheel speed
sensor/sensor ring?Replace sensor
or sensor ring.
Go to Step 11
Go to Step 8
8Is the output of each wheel speed sensor normal? (Refer to chart
C-1 or TC-1)
Go to Step 9
Replace wheel
speed sensor or
repair harness.
Go to Step 11
9Is the input of transmission normal? (Refer to chart C-2 or TC-2)
Go to Step 10
Replace switch or
repair harness.
Go to Step 11

5A–37 BRAKE CONTROL SYSTEM
StepNo Ye s
Action
5Is front 4WD controller normal?
Replace EHCU.
Go to Step 9
Replace 4WD
controller or
repair harness.
Go to Step 9
6Is transmission input normal? (Chart C-2 or TC-2)
Go to Step 7
Replace SW or
repair harness
Go to Step 9
7Is front 4WD controller normal?
Go to Step 8
Replace 4WD
controller or
repair harness.
Go to Step 9
8Is hydraulic unit grounded properly?Replace EHCU.
Go to Step 9Correct.
Go to Step 9
9Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the “Basic
diagnostic flow
chart.”
Go to Step 9
Chart A-4 Brake Pedal Feed Is Abnormal
StepActionYe sNo
1Is the stop light actuated when the brake pedal is depressed?Go to Step 2Go to Step 3
21. Turn the ignition switch off.
2. Disconnected EHCU connector.
3. Measure voltage between the EHCU connector terminal 10
and 15 when brake pedal is depressed.
Is the voltage equal to the battery voltage?
Go to Step 4
Harness NG
between brake
SW and EHCU.
Go to Step 7
3Is stop light fuse C-14 normal?
Go to Step 5
Replace fuse
C-14.
Go to Step 7
4Is there continuity between EHCU connector terminals, 12 and 15
to body ground?
Go to Step 6
Repair body
grounded
harness.
Go to Step 7
5Is the brake SW normal?Repair stop light
harness.
Go to Step 7Replace brake
SW.
Go to Step 7
6Is the check harness/connector for suspended disconnection?Hydraulic system
leakage or air
entry (Refer to
servicing
“Leakage or
brake fluid” )
Go to Step 7
Repair harness.
Go to Step 7
7Reconnect all components and ensure all components are
properly mounted.
Was this step finished?Repeat the “Basic
diagnostic flow
chart.”
Go to Step 7

5A–40
BRAKE CONTROL SYSTEM
Diagnosis By “ABS” Warning Light
Illumination Pattern
In the event that there is abnormality in the “ABS” warning
light illumination pattern while the key is in the ON position
or if the warning light is actuated during driving, trouble
should be diagnosed on a illumination pattern basis as
follows:
No.
Condition“ABS” Warning Light Illumination PatternDiagnostic
1Warning light is actu-
ated normallyNormal
2Warning light is not litWarning light lighting circuit
trouble
Go to Chart B-1
3Warning light remains
ONDiagnostic trouble codes are
stored.
Display diagnostic trouble
codes and diagnose on a
code basis according to the
flow charts.
4Warning light is actu-
ated while drivingDiagnostic trouble codes are
stored.
Display diagnostic trouble
codes and diagnose on a
code basis according to the
flow charts.
Diagnostic Trouble Codes (DTCs)
When the warning light in the meter remains ON, the
EHCU stores the fault identification and disables the
ABS.
1. How to display and erase DTCs:
NOTE:
If DTCs are not displayed, harness C-4 connector
terminal 30 and I-10 connector terminal 2 may be
disconnected. Repair the harness and try DTC
display again.
DTCs can be displayed also by TECH 2. Select mode
“F0: Diagnostic Trouble Codes” from Application
Menu.
1. How to start DTC display:
Confirm that the vehicle has come to a complete
stop (with the wheels standing still) and that the
brake pedal is not depressed. (Unless these two
conditions are satisfied, DTC display cannot be
started.)
With IGN OFF, connect #12 terminal with #4
terminal or # 5 terminal (GND) . Then turn IGN ON.

5A–41 BRAKE CONTROL SYSTEM
The DLC is located behind the center console
350RV010
Keep #12 terminal connected with #4 terminal or # 5
terminal (GND) during DTC display. (If #12 terminal
is separated from #4 terminal or # 5 terminal (GND)
during display, display will stop.)
2. DTC display:
DTC is displayed by blinking warning light.
Double-digit display.
First, normal DTC 12 is displayed three times and
then any other DTCs are displayed three times. (If
no other DTCs have been stored, the display of DTC
12 will be repeated.)
3. How to erase code:
Conduct brake switch ON/OFF operation 6 or more
times within 3 seconds of self-diagnosis startup.
The code cannot be erased if more than 3 seconds
have passed since self-diagnosis startup, or if
self-diagnosis has started with brake switched on
(brake pedal depressed).
B05RW005

5A–43 BRAKE CONTROL SYSTEM
Chart B-1 With the key in the ON position (Before starting the engine). Warning light (W/L)
is not activated.
StepActionYe sNo
1Is W/L fuse C-10 disconnected?Replace fuse.
Go to Step 5
Go to Step 2
2Is W/L burnt out?Replace W/L
bulb.
Go to Step 5
Go to Step 3
31. Turn the key off.
2. Disconnect EHCU connector.
3. Turn the key ON.
4. Measure the voltage between EHCU connector terminal 13
and 14.
Is the voltage equal to the battery voltage?
Go to Step 4
Repair harness
and connector.
Go to Step 5
4Is there continuity between EHCU connector terminals, 12 and 15
and body ground.Check harness
for suspected
disconnection.
No fault found:
Replace EHCU.
Go to Step 5
Repair harness
and connector.
Go to Step 5
5Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the “Basic
diagnostic flow
chart.”
Go to Step 5
Chart B-2 EHCU Abnormality (DTC 14)
StepActionYe sNo
11. Turn the key off.
2. Disconnect the EHCU connector.
3. Inspect EHCU ground.
Is there resistance between the EHCU connector terminals, 12
and 15 and body ground?
Go to Step 2
Repair the body
ground harness.
Go to Step 3
21. Turn the key off, connect the EHCU.
2. Erase the trouble code.
3. Turn Ignition off, then on, to perform system self-check.
4. If warning light remains on, display trouble codes once again.
Is the check trouble code 14?
Replace EHCU.
Go to Step 3
Inspect in
accordance with
the DTC
displayed.
31. Reconnect all components and ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the “Basic
diagnostic flow
chart.”
Go to Step 3

5A–52
BRAKE CONTROL SYSTEM
Chart B-20 FL Speed Sensor Short Circuit (DTC 61)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector
3. Measure the FL speed sensor resistance between EHCU
connector terminals 20 and 21.
Is the resistance between 1.3k and 1.9k ohms?
Go to Step 2Go to Step 3
2Is there play in the sensor/sensor rotor?
Go to Step 4
Repair.
Go to Step 6
3Measure the FL speed sensor resistance at the sensor connector.
Is the resistance between 1.3k and 1.9k ohms?Repair harness
abnormality
between sensors
and EHCU.
Go to Step 6
Replace sensor.
Go to Step 6
4Damage and powdered iron sticking to sensor/sensor ring?
Go to Step 5
Repair.
Go to Step 6
5Is sensor output normal? (Chart C-1-1 or TC-1)Check for faults
in harness
between speed
sensor and
EHCU.
Fault found:
repair, and
perform system
self-check.
No fault found:
replace EHCU.
Go to Step 6
Replace sensor.
Go to Step 6
61. Reconnect all components and ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the “Basic
diagnostic flow
chart.”
Go to Step 6
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop. Turn
the ignition switch to the ON position and drive the vehicle
at 12 km/h or higher to make sure that the warning light
goes out.