intermitt relay DAEWOO LACETTI 2004 Service User Guide

ENGINE CONTROLS 1F – 283
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1230
FUEL PUMP RELAY LOW VOLTAGE (1.4L DOHC)
Circuit Description
When the ignition switch is turned ON, the ECM will acti-
vate the fuel pump relay and run the in–tank fuel pump.
The fuel pump will operate as long as the engine is crank-
ing or running and the ECM is receiving ignition reference
pulses.
Conditions for Setting the DTC
S This DTC can be stored in ”key–on” status.
S An open or low voltage condition exists.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC was set as Failure Records data
only.
S This information will not be stored in the Freeze
Frame data.Conditions for Clearing the MIL/DTC
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
An Intermittent problem may be caused by a poor connec-
tion, rubbed through wire insulation, or wire that is broken
inside the insulation.
Any circuitry, that is suspected as causing the complaint,
should be thoroughly checked for the following conditions.
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminals to wire connection
S Physical damage to the wiring harness

1F – 286IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1230
FUEL PUMP RELAY LOW VOLTAGE (1.6L DOHC)
Circuit Description
When the ignition switch is turned ON, the ECM will acti-
vate the fuel pump relay and run the in–tank fuel pump.
The fuel pump will operate as long as the engine is crank-
ing or running and the ECM is receiving ignition reference
pulses.
Conditions for Setting the DTC
S This DTC can be stored in ”key–on” status.
S An open or low voltage condition exists.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Records buffers.
S A history DTC is stored.
S Coolant fan turns ON.
Conditions for Clearing the MIL/DTCS The MIL will turn off after consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for 10 sec-
onds.
Diagnostic Aids
An Intermittent problem may be caused by a poor connec-
tion, rubbed through wire insulation, or wire that is broken
inside the insulation.
Any circuitry, that is suspected as causing the complaint,
should be thoroughly checked for the following conditions.
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminals to wire connection
S Physical damage to the wiring harness

ENGINE CONTROLS 1F – 289
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1231
FUEL PUMP RELAY HIGH VOLTAGE (1.4L DOHC)
Circuit Description
When the ignition switch is turned ON, the ECM will acti-
vate the fuel pump relay and run the in–tank fuel pump.
The fuel pump will operate as long as the engine is crank-
ing or running and the ECM is receiving ignition reference
pulses.
Conditions for Setting the DTC
S This DTC can be stored in ”key–on” status.
S A high voltage condition exists.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will store conditions which were present
when the DTC was set as Failure Records data
only.
S This information will not be stored in the Freeze
Frame data.Conditions for Clearing the MIL/DTC
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
An Intermittent problem may be caused by a poor connec-
tion, rubbed through wire insulation, or wire that is broken
inside the insulation.
Any circuitry, that is suspected as causing the complaint,
should be thoroughly checked for the following conditions.
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminals to wire connection
S Physical damage to the wiring harness

1F – 292IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P1231
FUEL PUMP RELAY HIGH VOLTAGE (1.6L DOHC)
Circuit Description
When the ignition switch is turned ON, the ECM will acti-
vate the fuel pump relay and run the in–tank fuel pump.
The fuel pump will operate as long as the engine is crank-
ing or running and the ECM is receiving ignition reference
pulses.
Conditions for Setting the DTC
S This DTC can be stored in ”key–on” status.
S A high voltage condition exists.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illumi-
nate.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Records buffers.
S A history DTC is stored.
S Coolant fan turns ON.
Conditions for Clearing the MIL/DTCS The MIL will turn off after consecutive ignition
cycles in which the diagnostic runs without a fault.
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for 10 sec-
onds.
Diagnostic Aids
An Intermittent problem may be caused by a poor connec-
tion, rubbed through wire insulation, or wire that is broken
inside the insulation.
Any circuitry, that is suspected as causing the complaint,
should be thoroughly checked for the following conditions.
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminals to wire connection
S Physical damage to the wiring harness

1F – 398IENGINE CONTROLS
DAEWOO V–121 BL4
Diagnostic Aids
An intermittent may be caused by a rubbed–through wire
insulation or a wire contacting the exhaust.
Check for a poor connection or a damaged harness – in-
spect the harness connectors for the following conditions:
S Improper mating
S Broken locks
S Improperly formed
S Damaged terminals
S Poor terminal–to–wire connection
S Damaged harness
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.
1. The On–Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-cords data on the scan tool if applicable. This
creates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.
2. This step determines if DTC P0141 is the result of
a hard failure or an intermittent condition. With the
ignition ON, engine OFF, the HO2S2 voltage dis-
played on the scan tool should change within sever-
al minutes toward 0 or 1 volt, indicating that the
heater is working properly.
3. Probing terminal D of the HO2S2 connector verifies
if voltage is available to the HO2S2 heater.
4. If voltage is available at the connector, than it be-
comes a good voltage source to check for a ground
at terminal 3.
5. Determines if voltage is not available at the HO2S2
due to an open in the HO2S2 fuse or open ignition
feed circuit. If the fuse is open, determine if it was
due to a short in the ignition feed circuit before re-
placing the fuse.
DTC P0141 – Rear Heated Oxygen Sensor (HO2S2) Heater Circuit
Not Functioning
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) System
Check.
Was the check performed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition OFF.
2. Disconnect the Rear Heated Oxygen Sensor
(HO2S2) connector.
3. Turn the ignition ON.
4. Using a voltmeter, measure the voltage at ter-
minal 4 of HO2S2 and ground.
Is the voltage within the specified value?11–14 VGo to Step 3Go to
”Main Relay
Circuit Check”
31. Turn the ignition OFF.
2. Disconnect the HO2S2 connector.
3. Check the connections at HO2S2 connector,
terminal 3 and 4 and repair as needed.
Is the repair complete?–Go to Step 10Go to Step 4
4Disconnect the Engine control Module (ECM) con-
nector.
Check the connection at the ECM connector, termi-
nal M2 and repair as needed.–Go to Step 10Go to Step 5
51. Using ohmmeter, measure the resistance be-
tween terminal 3 of the HO2S2 and terminal
M2 of the ECM.
Is the resistance equal to the specified value?
1. Using a voltmeter, measure the voltage be-
tween terminal M2 of the ECM and ground.
Is the voltage within the specified value?0 Ω

0 VGo to Step 7Go to Step 6
6Repair an open or short to voltage circuit.
Is the repair complete?–Go to Step 10–

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–

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. . . . . . . . .

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.

ANTILOCK BRAKE SYSTEM 4F – 35
DAEWOO V–121 BL4
J3B14F09
DLC
(Data Link
Connector)
EBCM
DK BLUDK BLU
BLK/WHTC202
C110
11 2
1912 19
G106
DIAGNOSTIC TROUBLE CODE (DTC) C0060/C0065
LEFT FRONT INLET AND OUTLET VALVE SOLENOID
FAULT
Circuit Description
The solenoid valve coil circuits are supplied with power
from the battery when the valve relay is energized.
Switched ground is provided by the electronic brake con-
trol module (EBCM) to each coil.
Diagnosis
This procedure checks whether the left front inlet and out-
let valves are functioning.
Cause(s)
S A valve has failed.S A solenoid coil is open or shorted.
Fail Action
ABS is disabled, and the ABS warning lamp is turned ON
for the remainder of the ignition cycle. EBD is disabled. If
the failure is intermittent, the EBCM will enable the system
at the next ignition cycle and set a history DTC.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. This step begins the test of the inlet valve.
3. This step tests the outlet valve.

ANTILOCK BRAKE SYSTEM 4F – 37
DAEWOO V–121 BL4
J3B14F09
DLC
(Data Link
Connector)
EBCM
DK BLUDK BLU
BLK/WHTC202
C110
11 2
1912 19
G106
DIAGNOSTIC TROUBLE CODE (DTC) C0070/C0075
RIGHT FRONT INLET AND OUTLET VALVE SOLENOID
FAULT
Circuit Description
The solenoid valve coil circuits are supplied with power
from the battery when the valve relay is energized.
Switched ground is provided by the electronic brake con-
trol module (EBCM) to each coil.
Diagnosis
This procedure checks whether the right front inlet and
outlet valves are functioning.
Cause(s)
S A solenoid coil is open or shorted.Fail Action
ABS is disabled, and the ABS warning lamp is turned ON
for the remainder of the ignition cycle. EBD is disabled. If
the failure is intermittent, the EBCM will enable the system
at the next ignition cycle and set a history DTC.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
1. This begins the test of the inlet valve.
3. This tests the outlet valve.