2004 DAEWOO NUBIRA display

ENGINE CONTROLS 1F – 575
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
5Replace the sensor in the affected circuit, if a Diag-
nostic Trouble Code (DTC) was stored for this circuit
(except for the DTCs P0171 and P0172.
Is the repair complete?–System OK–
6Does an intermittent Malfunction Indicator Lamp
(MIL) or DTC occur?–Go toStep 7Go toStep 8
71. Check for a faulty relay, electronic control mod-
ule (ECM) driven solenoid, or switch.
2. Check for improper installation of electrical de-
vices, such as lights, two–way radios, electric
motors, etc.
3. Inspect the ignition control wires for proper
routing (away from ignition wires, ignition sys-
tem components, and the generator).
4. Check for a short–to–ground in the MIL circuit
or the DLC ”test” terminal.
5. Inspect the ECM ground connections.
6. Correct or repair the affected circuits as need-
ed.
Is the repair complete?–System OK–
81. Check for a loss of DTC memory.
2. 2. Disconnect the Throttle Position Sensor.
3. Run the engine at idle until the MIL comes on.
4. Turn the ignition OFF.
Is DTC P0122 stored in memory?–Go toStep 10Go toStep 9
9Replace the ECM.
Is the repair complete?–System OK–
10Does the vehicle stall while driving?–Go toStep 11Go toStep 12
11Monitor the Front Heated Oxygen Sensor (HO2S1)
and the injector base pulse width with the scan tool.
Does the scan tool display a steady low voltage
(about 0 mv) for the HO2S1 sensor with the control
module commanding an injector base pulse width of
the value specified?8 msGo toStep 9Go toStep 12
121. Check for an open diode across the A/C clutch
and for other open diodes.
2. Repair or replace any components as needed.
Is the repair complete?–System OK–

ENGINE CONTROLS 1F – 629
DAEWOO V–121 BL4
tentially interfere with the operation of the Exhaust Gas
Recirculation (EGR) valve and thereby turn on the MIL.
Small leaks in the exhaust system near the post catalyst
oxygen sensor can also cause the MIL to turn on.
Aftermarket electronics, such as cellular phones, stereos,
and anti–theft devices, may radiate electromagnetic inter-
ference (EMI) into the control system if they are improperly
installed. This may cause a false sensor reading and turn
on the MIL.
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition system.
If the ignition system is rain–soaked, it can temporarily
cause engine misfire and turn on the MIL.
Refueling
A new EOBD diagnostic checks the integrity of the entire
Evaporative (EVAP) Emission system. If the vehicle is re-
started after refueling and the fuel cap is not secured cor-
rectly, the on–board diagnostic system will sense this as
a system fault, turn on the MIL, and set DTC P0440.
Vehicle Marshaling
The transportation of new vehicles from the assembly
plant to the dealership can involve as many as 60 key
cycles within 2 to 3 miles of driving. This type of operation
contributes to the fuel fouling of the spark plugs and will
turn on the MIL with a set DTC P0300.
Poor Vehicle Maintenance
The sensitivity of EOBD diagnostics will cause the MIL to
turn on if the vehicle is not maintained properly. Restricted
air filters, fuel filters, and crankcase deposits due to lack
of oil changes or improper oil viscosity can trigger actual
vehicle faults that were not previously monitored prior to
EOBD. Poor vehicle maintenance can not be classified as
a ”non–vehicle fault,” but with the sensitivity of EOBD
diagnostics, vehicle maintenance schedules must be
more closely followed.
Severe Vibration
The Misfire diagnostic measures small changes in the
rotational speed of the crankshaft. Severe driveline vibra-
tions in the vehicle, such as caused by an excessive
amount of mud on the wheels, can have the same effect
on crankshaft speed as misfire and, therefore, may set
DTC P0300.
Related System Faults
Many of the EOBD system diagnostics will not run if the
engine controlmodule (ECM) detects a fault on a related
system or component. One example would be that if the
ECM detected a Misfire fault, the diagnostics on the cata-
lytic converter would be suspended until the Misfire fault
was repaired. If the Misfire fault is severe enough, the cat-
alytic converter can be damaged due to overheating andwill never set a Catalyst DTC until the Misfire fault is re-
paired and the Catalyst diagnostic is allowed to run to
completion. If this happens, the customer may have to
make two trips to the dealership in order to repair the ve-
hicle.
SERIAL DATA COMMUNICATIONS
Class II Serial Data Communications
Government regulations require that all vehicle manufac-
turers establish a common communication system. This
vehicle utilizes the ”Class II” communication system. Each
bit of information can have one of two lengths: long or
short. This allows vehicle wiring to be reduced by transmit-
ting and receiving multiple signals over a single wire. The
messages carried on Class II data streams are also priori-
tized. If two messages attempt to establish communica-
tions on the data line at the same time, only the message
with higher priority will continue. The device with the lower
priority message must wait. Themost significant result of
this regulation is that it provides scan tool manufacturers
with the capability to access data from any make or model
vehicle that is sold.
The data displayed on the other scan tool will appear the
same, with some exceptions. Some scan tools will only be
able to display certain vehicle parameters as values that
are a coded representation of the true or actual value. On
this vehicle the scan tool displays the actual values for ve-
hicle parameters. It will not be necessary to perform any
conversions from coded values to actual values.
ON–BOARD DIAGNOSTIC (EOBD)
On–Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which is
a pass or fail reported to the diagnostic executive. When
a diagnostic test reports a pass result, the diagnostic
executive records the following data:
S The diagnostic test has been completed since the
last ignition cycle.
S The diagnostic test has passed during the current
ignition cycle.
S The fault identified by the diagnostic test is not cur-
rently active.
When a diagnostic test reports a fail result, the diagnostic
executive records the following data:
S The diagnostic test has been completed since the
last ignition cycle.
S The fault identified by the diagnostic test is current-
ly active.
S The fault has been active during this ignition cycle.
S The operating conditions at the time of the failure.
Remember, a fuel trim Diagnostic Trouble Code (DTC)
may be triggered by a list of vehicle faults. Make use of all
information available (other DTCs stored, rich or lean con-
dition, etc.) when diagnosing a fuel trim fault.

1F – 632IENGINE CONTROLS
DAEWOO V–121 BL4
READING DIAGNOSTIC TROUBLE
CODES
The procedure for reading diagnostic trouble code(s) is to
use a diagnostic scan tool. When reading Diagnostic
Trouble Codes (DTCs), follow the instructions supplied by
tool manufacturer.
DTC Modes
On On–Board Diagnostic (EOBD) passenger cars there
are five options available in the scan tool DTC mode to dis-
play the enhanced information available. A description of
the new modes, DTC Info and Specific DTC, follows. After
selecting DTC, the following menu appears:
S DTC Info.
S Specific DTC.
S Freeze Frame.
S Fail Records (not all applications).
S Clear Info.
The following is a brief description of each of the sub me-
nus in DTC Info and Specific DTC. The order in which they
appear here is alphabetical and not necessarily the way
they will appear on the scan tool.
DTC Information Mode
Use the DTC info mode to search for a specific type of
stored DTC information. There are seven choices. The
service manual may instruct the technician to test for
DTCs in a certain manner. Always follow published service
procedures.
To get a complete description of any status, press the ”En-
ter” key before pressing the desired F–key. For example,
pressing ”Enter” then an F–key will display a definition of
the abbreviated scan tool status.
DTC Status
This selection will display any DTCs that have not run dur-
ing the current ignition cycle or have reported a test failure
during this ignition up to a maximum of 33 DTCs. DTC
tests which run and pass will cause that DTC number to
be removed from the scan tool screen.
Fail This Ign. (Fail This Ignition)
This selection will display all DTCs that have failed during
the present ignition cycle.
History
This selection will display only DTCs that are stored in the
ECM’s history memory. It will not display type CNL DTCs
that have not requested the Malfunction Indicator Lamp
(MIL). It will display all type A, B and E DTCs that have re-
quested the MIL and have failed within the last 40 warm–
up cycles. In addition, it will display all type C and type D
DTCs that have failed within the last 40 warm–up cycles.
Last Test Fail
This selection will display only DTCs that failed the last
time the test ran. The last test may have run during a pre-
vious ignition cycle if a type A or type B DTC is displayed.
For type C and type D DTCs, the last failure must have oc-
curred during the current ignition cycle to appear as Last
Test Fail.
MIL Request
This selection will display only DTCs that are requesting
the MIL. Type C and type D DTCs cannot be displayed us-
ing this option. This selection will report type B DTCs only
after the MIL has been requested.
Not Run SCC (Not Run Since Code Clear)
This option will display up to 33 DTCs that have not run
since the DTCs were last cleared. Since any displayed
DTCs have not run, their condition (passing or failing) is
unknown.
Test Fail SCC (Test Failed Since Code
Clear)
This selection will display all active and history DTCs that
have reported a test failure since the last time DTCs were
cleared. DTCs that last failed more than 40 warm–up
cycles before this option is selected will not be displayed.
Specific DTC Mode
This mode is used to check the status of individual diag-
nostic tests by DTC number. This selection can be ac-
cessed if a DTC has passed, failed or both. Many EOBD
DTC mode descriptions are possible because of the ex-
tensive amount of information that the diagnostic execu-
tive monitors regarding each test. Some of the many pos-
sible descriptions follow with a brief explanation.
The ”F2” key is used, in this mode, to display a description
of the DTC. The ”Yes” and ”No” keys may also be used to
display more DTC status information. This selection will
only allow entry of DTC numbers that are supported by the
vehicle being tested. If an attempt is made to enter DTC
numbers for tests which the diagnostic executive does not
recognize, the requested information will not be displayed
correctly and the scan tool may display an error message.
The same applies to using the DTC trigger option in the
Snapshot mode. If an invalid DTC is entered, the scan tool
will not trigger.
Failed Last Test
This message display indicates that the last diagnostic
test failed for the selected DTC. For type A and type B
DTCs, this message will be displayed during subsequent
ignition cycles until the test passes or DTCs are cleared.
For type C and type D DTCs, this message will clear when
the ignition is cycled.
Failed Since Clear
This message display indicates that the DTC has failed at
least once within the last 40 warm–up cycles since the last
time DTCs were cleared.

ENGINE CONTROLS 1F – 633
DAEWOO V–121 BL4
Failed This Ig. (Failed This Ignition)
This message display indicates that the diagnostic test
has failed at least once during the current ignition cycle.
This message will clear when DTCs are cleared or the igni-
tion is cycled.
History
This message display indicates that the DTC has been
stored in memory as a valid fault. A DTC displayed as a
History fault may not mean that the fault is no longer pres-
ent. The history description means that all the conditions
necessary for reporting a fault have been met (maybe
even currently), and the information was stored in the con-
trol module memory.
MIL Requested
This message display indicates that the DTC is currently
causing the MIL to be turned ON. Remember that only
type A and type B DTCs can request the MIL. The MIL re-
quest cannot be used to determine if the DTC fault condi-
tions are currently being experienced. This is because the
diagnostic executive will require up to three trips during
which the diagnostic test passes to turn OFF the MIL.
Not Run Since CI (Not Run Since Cleared)
This message display indicates that the selected diagnos-
tic test has not run since the last time DTCs were cleared.
Therefore, the diagnostic test status (passing or failing) is
unknown. After DTCs are cleared, this message will con-
tinue to be displayed until the diagnostic test runs.
Not Run This Ig. (Not Run This Ignition)
This message display indicates that the selected diagnos-
tic test has not run during this ignition cycle.
Test Ran and Passed
This message display indicates that the selected diagnos-
tic test has done the following:
S Passed the last test.
S Run and passed during this ignition cycle.
S Run and passed since DTCs were last cleared.
If the indicated status of the vehicle is ”Test Ran and
Passed” after a repair verification, the vehicle is ready to
be released to the customer.
If the indicated status of the vehicle is ”Failed This Ignition”
after a repair verification, then the repair is incomplete and
further diagnosis is required.
Prior to repairing a vehicle, status information can be used
to evaluate the state of the diagnostic test, and to help
identify an intermittent problem. The technician can con-
clude that although the MIL is illuminated, the fault condi-
tion that caused the code to set is not present. An intermit-
tent condition must be the cause.
PRIMARY SYSTEM – BASED
DIAGNOSTICS
There are primary system–based diagnostics which eval-
uate system operation and its effect on vehicle emissions.
The primary system–based diagnostics are listed below
with a brief description of the diagnostic function:
Oxygen Sensor Diagnosis
The fuel control Front Heated Oxygen Sensor (HO2S1) is
diagnosed for the following conditions:
S Slow response.
S Response time (time to switch R/L or L/R).
S Inactive signal (output steady at bias voltage
approx. 450 mv).
S Signal fixed high.
S Signal fixed low.
The catalyst monitor Rear Heated Oxygen Sensor
(HO2S2) is diagnosed for the following conditions:
S Heater performance (time to activity on cold start).
S Signal fixed low during steady state conditions or
power enrichment (hard acceleration when a rich-
mixture should be indicated).
S Signal fixed high during steady state conditions or
deceleration mode (deceleration when a lean mix-
ture should be indicated).
S Inactive sensor (output steady at approximately 438
mv).
If the oxygen sensor pigtail wiring, connector or terminal
are damaged, the entire oxygen sensor assembly must be
replaced. Do not attempt to repair the wiring, connector or
terminals. In order for the sensor to function properly, it
must have clean reference air provided to it. This clean air
reference is obtained by way of the oxygen sensor wire(s).
Any attempt to repair the wires, connector or terminals
could result in the obstruction of the reference air and de-
grade oxygen sensor performance.
Misfire Monitor Diagnostic Operation
The misfire monitor diagnostic is based on crankshaft
rotational velocity (reference period) variations. The en-
gine control module (ECM) determines crankshaft rota-
tional velocity using the Crankshaft Position (CKP) sensor
and the Camshaft Position (CMP) sensor. When a cylinder
misfires, the crankshaft slows down momentarily. By mon-
itoring the CKP and CMP sensor signals, the ECM can cal-
culate when a misfire occurs.
For a non–catalyst damaging misfire, the diagnostic will be
required to monitor a misfire present for between
1000–3200 engine revolutions.
For catalyst–damaging misfire, the diagnostic will respond
to misfire within 200 engine revolutions.
Rough roads may cause false misfire detection. A rough
road will cause torque to be applied to the drive wheels and
drive train. This torque can intermittently decrease the
crankshaft rotational velocity. This may be falsely de-
tected as a misfire.

1F – 634IENGINE CONTROLS
DAEWOO V–121 BL4
A rough road sensor, or G sensor, works together with the
misfire detection system. The G sensor produces a volt-
age that varies along with the intensity of road vibrations.
When the ECM detects a rough road, the misfire detection
system is temporarily disabled.
Misfire Counters
Whenever a cylinder misfires, the misfire diagnostic
counts the misfire and notes the crankshaft position at the
time the misfire occurred. These ”misfire counters” are ba-
sically a file on each engine cylinder. A current and a histo-
ry misfire counter are maintained for each cylinder. The
misfire current counters (Misfire Cur #1–4) indicate the
number of firing events out of the last 200 cylinder firing
events which were misfires. The misfire current counter
will display real time data without a misfire Diagnostic
Trouble Code (DTC) stored. The misfire history counters
(Misfire Hist #1–4) indicate the total number of cylinder fir-
ing events which were misfires. The misfire history count-
ers will display 0 until the misfire iagnostic has failed and
a DTC P0300 is set. Once the misfire DTC P0300 is set,
the misfire history counters will be updated every 200 cyl-
inder firing events. A misfire counter is maintained for each
cylinder.
If the misfire diagnostic reports a failure, the diagnostic
executive reviews all of the misfire counters before report-
ing a DTC. This way, the diagnostic executive reports the
most current information.
When crankshaft rotation is erratic, a misfire condition will
be detected. Because of this erratic condition, the data
that is collected by the diagnostic can sometimes incor-
rectly identify which cylinder is misfiring.
Use diagnostic equipment to monitor misfire counter data
on On–Board Diagnostic (EOBD) compliant vehicles.
Knowing which specific cylinder(s) misfired can lead to the
root cause, even when dealing with amultiple cylinder mis-
fire. Using the information in the misfire counters, identify
which cylinders are misfiring. If the counters indicate cylin-
ders numbers 1 and 4 misfired, look for a circuit or compo-
nent common to both cylinders number 1 and 4.
The misfire diagnostic may indicate a fault due to a tempo-
rary fault not necessarily caused by a vehicle emission
system malfunction. Examples include the following
items:
S Contaminated fuel.S Low fuel.
S Fuel–fouled spark plugs.
S Basic engine fault.
Fuel Trim System Monitor Diagnostic
Operation
This system monitors the averages of short–term and
long–term fuel trim values. If these fuel trim values stay at
their limits for a calibrated period of time, a malfunction is
indicated. The fuel trim diagnostic compares the averages
of short–term fuel trim values and long–term fuel trim val-
ues to rich and lean thresholds. If either value is within the
thresholds, a pass is recorded. If both values are outside
their thresholds, a rich or lean DTC will be recorded.
The fuel trim system diagnostic also conducts an intrusive
test. This test determines if a rich condition is being
caused by excessive fuel vapor from the Evaporative
(EVAP) Emission canister. In order to meet EOBD require-
ments, the control module uses weighted fuel trim cells to
determine the need to set a fuel trim DTC. A fuel trim DTC
can only be set if fuel trim counts in the weighted fuel trim
cells exceed specifications. This means that the vehicle
could have a fuel trim problem which is causing a problem
under certain conditions (i.e., engine idle high due to a
small vacuum leak or rough idle due to a large vacuum
leak) while it operates fine at other times. No fuel trim DTC
would set (although an engine idle speed DTC or HO2S2
DTC may set). Use a scan tool to observe fuel trim counts
while the problem is occurring.
A fuel trim DTC may be triggered by a number of vehicle
faults. Make use of all information available (other DTCs
stored, rich or lean condition, etc.) when diagnosing a fuel
trim fault.
Fuel Trim Cell Diagnostic Weights
No fuel trim DTC will set regardless of the fuel trim counts
in cell 0 unless the fuel trim counts in the weighted cells are
also outside specifications. This means that the vehicle
could have a fuel trim problem which is causing a problem
under certain conditions (i.e. engine idle high due to a
small vacuum leak or rough due to a large vacuum leak)
while it operates fine at other times. No fuel trim DTC
would set (although an engine idle speed DTC or HO2S2
DTC may set). Use a scan tool to observe fuel trim counts
while the problem is occurring.

SECTION : 4F
ANTILOCK BRAKE SYSTEM
CAUTION : Disconnect the negative battery cable before removing or installing any electrical unit or when a tool
or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable will help
prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwise noted.
TABLE OF CONTENTS
SPECIFICATIONS4F–2 . . . . . . . . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 4F–2. . . . . . . . . .
SPECIAL TOOLS4F–2 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools Table 4F–2. . . . . . . . . . . . . . . . . . . . . . . .
SCHEMATIC AND ROUTING DIAGRAMS4F–3 . . . . .
Abs System Circuit (I) 4F–3. . . . . . . . . . . . . . . . . . . . . .
Abs System Circuit (II) 4F–4. . . . . . . . . . . . . . . . . . . . .
Ebcm Connector Face View 4F–5. . . . . . . . . . . . . . . . .
COMPONENT LOCATOR4F–6 . . . . . . . . . . . . . . . . . . . .
ABS/EBD System Drive 4F–6. . . . . . . . . . . . . . . . . . . .
DIAGNOSIS4F–7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Circuit Check 4F–7. . . . . . . . . . . . . . . . . . .
ABS Indicator Lamp Inoperative 4F–9. . . . . . . . . . . . .
Power Supply to Control Module,
No DTCs Stored 4F–12. . . . . . . . . . . . . . . . . . . . . . . .
ABS Indicator Lamp Illuminated Continuously,
No DTCs Stored 4F–16. . . . . . . . . . . . . . . . . . . . . . . .
Electronic Brake–Force Distribution (EBD)
System Indicator Lamp Inoperative 4F–18. . . . . . . .
SELF–DIAGNOSTICS 4F–22. . . . . . . . . . . . . . . . . . . .
DISPLAYING DTCs 4F–22. . . . . . . . . . . . . . . . . . . . . . .
CLEARING DTCs 4F–22. . . . . . . . . . . . . . . . . . . . . . . .
INTERMITTENTS AND POOR
CONNECTIONS 4F–22. . . . . . . . . . . . . . . . . . . . . . . .
DTC C0035 Left Front Wheel Speed Sensor
Circuit Malfunction 4F–23. . . . . . . . . . . . . . . . . . . . . .
DTC C0040 Right Front Wheel Speed Sensor
Circuit Malfunction 4F–26. . . . . . . . . . . . . . . . . . . . . .
DTC C0045 Left Rear Wheel Speed Sensor
Circuit Malfunction 4F–29. . . . . . . . . . . . . . . . . . . . . .
DTC C0050 Right Rear Wheel Speed Sensor
Circuit Malfunction 4F–32. . . . . . . . . . . . . . . . . . . . . .
DTC C0060/C0065 Left Front Inlet and
Outlet Valve Solenoid Fault 4F–35. . . . . . . . . . . . . . .
DTC C0070/C0075 Right Front Inlet and
Outlet Valve Solenoid Fault 4F–37. . . . . . . . . . . . . . . DTC C0080/C0085 Left Rear Inlet and
Outlet Valve Solenoid Fault 4F–39. . . . . . . . . . . . . . .
DTC C0090/C0095 Right Rear Inlet and
Outlet Valve Solenoid Fault 4F–41. . . . . . . . . . . . . . .
DTC C0110 Pump Motor Circuit Malfunction 4F–43. .
DTC C0121 Valve Relay Circuit Malfunction 4F–45. .
DTC C0161 ABS Brake Switch Circuit
Malfunction 4F–47. . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC C0245 Wheel Speed Sensor Frequency
Error 4F–50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC C0550 ABS Control Module Internal
Fault 4F–54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC C0800 Low Voltage Fault 4F–56. . . . . . . . . . . . .
DTC C0931 Overheated 4F–59. . . . . . . . . . . . . . . . . . .
MAINTENANCE AND REPAIR4F–60 . . . . . . . . . . . . . .
ON–VEHICLE SERVICE 4F–60. . . . . . . . . . . . . . . . . . . .
Service Precautions 4F–60. . . . . . . . . . . . . . . . . . . . . . .
Bleeding System 4F–61. . . . . . . . . . . . . . . . . . . . . . . . .
ABS 5.3 Assembly 4F–61. . . . . . . . . . . . . . . . . . . . . . . .
Front Wheel Speed Sensor 4F–62. . . . . . . . . . . . . . . .
Front Wheel Speed Sensor Jumper Harness 4F–63.
Rear Wheel Speed Sensor 4F–64. . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION4F–65 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Knowledge Required 4F–65. . . . . . . . . . . . . . . . .
ABS System Components 4F–65. . . . . . . . . . . . . . . . .
Base Braking Mode 4F–65. . . . . . . . . . . . . . . . . . . . . . .
Antilock Braking Mode 4F–66. . . . . . . . . . . . . . . . . . . . .
EBD System 4F–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electronic Brake–Force Distribution (EBD) Failure
Matrix 4F–70. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tires and ABS/EBD 4F–71. . . . . . . . . . . . . . . . . . . . . . .
Electronic Brake Control Module (EBCM) 4F–71. . . .
Front Wheel Speed Sensors 4F–71. . . . . . . . . . . . . . .
Front Wheel Speed Sensor Rings 4F–71. . . . . . . . . . .
Rear Wheel Speed Sensors and Rings 4F–71. . . . . .
Valve Relay and Pump Motor Relay 4F–71. . . . . . . . .

ANTILOCK BRAKE SYSTEM 4F – 7
DAEWOO V–121 BL4
DIAGNOSIS
J3B14F04
60A Ef230A Ef5
2
42
C107 C105
2
C110
G106
A19
A13 A1 A14
C110 C202
C202WHT LT GRN
DK
GRN LT GRN/
BLK
BLK
DK BLUDK BLU
PPL/WHT
PPL/WHT ABS
TCS Parking
Brake
Hot at all times
RED REDRED/WHT
Ignition
Switch
RED
RED
I/P Cluster
EBCM8
20
22 2216 41
1211
18 1621
1
C107
10A F410AF11
32 31
43
6 62 C201
C201 C201C201
C110 C202
Hot in Run and Start
30
4
1711
C202
15
B15
DLC
(Data Link
Connector)12
G106
BLK/WHTOil Feeding
Connector
”2” Ter.
BRNBRN BRN
BRN PNK PNK PNK
19J1
59B1
ONStart Lock
Acc
IG1
19
DIAGNOSTIC CIRCUIT CHECK
The Diagnostic Circuit Check is an organized approach to
identifying a problem created by an antilock brake system
(ABS) malfunction. It must be the starting point for any
ABS complaint diagnosis because it directs the service
technician to the next logical step in diagnosing the com-
plaint.
Diagnostic Process
Perform the following steps in order when servicing the
ABS/EBD system. Failure to do so may result in the loss
of important diagnostic data and may lead to difficulties
and time–consuming diagnosis procedures.1. Perform the tests of the table below.
2. Perform a road test if directed by the table.
S Test drive the vehicle while using the snapshot
feature of the scan tool.
S Perform normal acceleration, stopping, and turn-
ing maneuvers.
S If this does not reproduce the malfunction, per-
form an ABS stop on a low friction surface such
as gravel.
3. Clear the diagnostic trouble codes (DTCs) after all
system malfunctions have been corrected.
Diagnostic Circuit Check
StepActionValue(s)YesNo
11. Install the scan tool.
2. Turn ignition switch to ON.
3. Select the Data List mode.
Is the scan tool receiving data from the electronic
brake control module (EBCM) ?–Go to Step 2Go to Step 6
2Check the display.
Are there any current DTCs displayed?–Refer to the ap-
plicable DTC
tableGo to Step 3

4F – 22IANTILOCK BRAKE SYSTEM
DAEWOO V–121 BL4
SELF–DIAGNOSTICS
Important : The electronic brake control module (EBCM)
turns the valve relay off when a diagnostic trouble code
(DTC) is set. The scan tool will indicate that the valve relay
is off when it is used to monitor the data list. This is normal
and should not be considered a malfunction.
Important : For safety reasons it is recommended that the
vehicle not be driven with test equipment connected. Ex-
ception : for testing of wheel speeds provided the test reg-
ulations are met.
The EBCM performs system self–diagnostics and can de-
tect and often isolate system malfunctions. When it de-
tects a malfunction, the EBCM sets a DTC that represents
the malfunction, turns ON the ABS and/or the EBD indica-
tors in most instances, and may disable the ABS and/or
the EBD functions as necessary for the duration of the igni-
tion cycle.
Once each ignition cycle, the EBCM performs an automat-
ic test when the vehicle speed > 6 km/h and the brake ped-
al is not actuated or when the vehicle speed > 15 km/h and
the brake pedal is actuated. In the course of this test, the
system cycles each valve solenoid and the pump motor,
along with the necessary relays, to check component op-
eration. If the EBCM detects any malfunctions, it will set
a DTC as described above.
DISPLAYING DTCS
Tools Required
Scan Tool
DTCs can be read through the use of the scan tool.
CLEARING DTCS
Tools Required
Scan Tool
The diagnostic trouble codes (DTCs) in the electronic
brake control module (EBCM) memory are erased:S Use the scan tool ”Clear DTCs” selection.
The method is detailed below. Be sure to verify proper sys-
tem operation and absence of DTCs when the clearing
procedure is completed.
The EBCM will not permit DTC clearing until all DTCs have
been displayed. Also, DTCs cannot be cleared by discon-
necting the EBCM, disconnecting the battery cables, or
turning the ignition switch to LOCK.
Scan Tool Method
The scan tool can clear ABS system DTCs using the mass
storage cartridge.
1. Install the scan tool and the mass storage cartridge.
2. Select ”Fault Memory.”
3. Select ”Clear Fault Memory.”
Clearing the fault memory cannot reset a valve relay which
was shut down when the fault was recognized. Changes
are possible only after the fault has been eliminated and
the next ignition cycle has begun.
INTERMITTENTS AND POOR
CONNECTIONS
As with most electronic systems, intermittent malfunctions
may be difficult to diagnose accurately. The following is a
method to try to isolate an intermittent malfunction, espe-
cially in wheel speed circuitry.
If an ABS malfunction occurs, the ABS indicator will illumi-
nate during the ignition cycle in which the malfunction was
detected. If it is an intermittent problem which seems to
have corrected itself (ABS indicator off), a history DTC will
be stored. Also stored will be the history data of the DTC
at the time the malfunction occurred. Use the scan tool
modular diagnostic system to read ABS history data.
Most intermittents are caused by faulty electrical connec-
tions or wiring, although a sticking relay or solenoid can oc-
casionally be at fault.