main relay DAEWOO LACETTI 2004 Service Service Manual

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.

ANTILOCK BRAKE SYSTEM 4F – 39
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) C0080/C0085
LEFT REAR 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 rear inlet and outlet
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 begins the test of the inlet valve.
3. This tests the outlet valve.

ANTILOCK BRAKE SYSTEM 4F – 41
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) C0090/C0095
RIGHT REAR 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 rear 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 begins the test of the inlet valve.
3. This tests the outlet valve.

ANTILOCK BRAKE SYSTEM 4F – 45
DAEWOO V–121 BL4
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 TROUBLE CODE (DTC) C0121
VALVE RELAY CIRCUIT MALFUNCTION
Circuit Description
When the ABS is active, the valve relay provides voltage
to actuate the solenoid valves. The valves do not use this
voltage unless the ABS control module provides the
ground for each solenoid coil.
DTC C0121 will set if the valve relay voltage is low or if the
relay supply line is at 12 volts when the ABS control mod-
ule is not requesting it. This DTC will also set if the ABS
control module detects three or more solenoid valve cir-
cuits are open or shorted during the self–test.
Diagnosis
This procedure checks whether there is a poor ground
connection for the electronic brake control module
(EBCM).Cause(s)
S A connector terminal is corroded.
S The wiring harness is damaged.
S The ground terminal is not conducting properly.
S The EBCM is defective.
Fail Action
ABS/EBD is disabled, and the ABS / EBD warning lamp
is turned ON for the remainder of the ignition cycle. If the
failure is intermittent, the control module will enable the
system at the next ignition cycle and set a history DTC
C0121.
Diagnostic Aids
It is very important to perform a thorough inspection of the
wiring and the connectors. Failure to do so may result in
misdiagnosis, causing part replacement with reappear-
ance of the malfunction.

ANTILOCK BRAKE SYSTEM 4F – 71
DAEWOO V–121 BL4
TIRES AND ABS/EBD
Replacement Tires
Tire size is important for proper performance of the ABS
system. Replacement tires should be the same size, load
range, and construction as the original tires. Replace tires
in axle sets and only with tires of the same tire perfor-
mance criteria (TPC) specification number. Use of any
other size or type may seriously affect the ABS operation.
TIRES AND ABS/EBD
Notice : There is no serviceable or removable EEPROM.
The EBCM must be replaced as an assembly.
The EBCM is attached to the hydraulic unit in the engine
compartment. The controlling element of ABS 5.3 is a mi-
croprocessor–based EBCM. Inputs to the system include
the four wheel speed sensors, the stoplamp switch, the
ignition switch, and the unswitched battery voltage. There
is an output to a bi–directional serial data link, located in
pin K of Data Link Connector (DLC) for service diagnostic
tools and assembly plant testing.
The EBCM monitors the speed of each wheel. If any wheel
begins to approach lockup and the brake switch is closed
(brake pedal depressed), the EBCM controls the sole-
noids to reduce brake pressure to the wheel approaching
lockup. Once the wheel regains traction, brake pressure
is increased until the wheel again begins to approach lock-
up. This cycle repeats until either the vehicle comes to a
stop, the brake pedal is released, or no wheels approach
lockup.
Additionally, the EBCM monitors itself, each input (except
the serial data link), and each output for proper operation.
If it detects any system malfunction, the EBCM will store
a DTC in nonvolatile memory (EEPROM) (DTCs will not
disappear if the battery is disconnected). Refer to ”Self
Diagnostics” in this section for more detailed information.
FRONT WHEEL SPEED SENSOR
The front wheel speed sensors are of a variable reluctance
type. Each sensor is attached to the steering knuckle,
close to a toothed ring. The result, as teeth pass by the
sensor, is an AC voltage with a frequency proportional to
the speed of the wheel. The magnitude of the voltage and
frequency increase with increasing speed. The sensor is
not repairable, nor is the air gap adjustable.
FRONT WHEEL SPEED SENSOR
RINGS
The toothed ring mentioned above is pressed onto the
wheel–side (outer) constant velocity joint. Each ring con-
tains 47 equally spaced teeth. Exercise care during ser-
vice procedures to avoid prying or contacting this ring. Ex-cessive contact may cause damage to one or more teeth.
If the ring is damaged, the wheel–side constant velocity
joint must be replaced.
REAR WHEEL SPEED SENSOR AND
RINGS
The rear wheel speed sensors operate in the same man-
ner as the front wheel speed sensors. They incorporate a
length of flexible harness with the connector attached to
the end of the harness. The rear wheel speed rings are in-
corporated into the hub assemblies and cannot be re-
placed separately, but require replacement of the rear
hub/bearing assembly.
VALUE RELAY AND PUMP MOTOR
RELAY
The valve relay and the motor pump relay are located in-
side the electronic brake control module (EBCM) and are
not replaceable. If one should fail, replace the EBCM.
WIRING HARNESS
The wiring harness is the mechanism by which the elec-
tronic brake control module (EBCM) is electrically con-
nected to power and to ground, to the wheel speed sen-
sors, the fuses, the switches, the indicators, and the serial
communications port. The components, considered part
of the wiring harness, are the wires that provide electrical
interconnection, and connectors (terminals, pins, con-
tacts, or lugs) that provide an electrical/mechanical inter-
face from the wire to a system component.
INDICATORS
The electronic brake control module (EBCM) continuously
monitors itself and the other ABS components. If the
EBCM detects a problem with the system, the amber ABS
indicator will light continuously to alert the driver to the
problem. An illuminated ABS indicator indicates that the
ABS system has detected a problem that affects the op-
eration of ABS. No antilock braking will be available. Nor-
mal, non–antilock brake performance will remain. In order
to regain ABS braking ability, the ABS must be serviced.
The red BRAKE indicator will be illuminated when the sys-
tem detects a low brake fluid level in the master cylinder
or when the parking brake switch is closed (the parking
brake is engaged) or EBD system is diabled.
WARNING : EBD INDICATOR LAMP WIRING IS CON-
NECTED TO THE PARKING BRAKE LAMP. IF THE
PARKING BRAKE LAMP IS TURNED ON WHEN YOU
DRIVING, CHECKING ON WHETHER THE PARKING
BRAKE LEVER IS ENAGED OR THE BRAKE FLUID
LEVEL IS LOW. IF THE SYSTEM HAS NO PROBLEM,
THE EBD SYSTEM IS WORKING IMPROPERLY. THE
EBD SYSTEM MUST BE SERVICED.

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 101
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P0720
OUTPUT SPEED SENSOR(OSS) CIRCUIT MALFUNCTION
Circuit Description
The vehicle A/T OSS is a magnetic inductive pickup that
relays information relative to vehicle speed to the TCM.
Vehicle speed information is used by the TCM to control
shift timing, line pressure, and TCC apply and release.
The output speed sensor mounts in the case at the speed
sensor rotor, which is pressed onto the spur gear. An air
gap of 0.1mm~1.3mm(0.004~0.05in) is maintained be-
tween the sensor and the teeth on the spur gear teeth. The
sensor consists of a permanent magnet surrounded by a
coil of wire. As the differential rotates, an AC signal in-
duces a higher frequency and voltage measurement at the
sensor. Sensor resistance should measure
at 20°C
(68°F). Sensor can measure from 20HZ~8,000HZ.
Conditions for Setting The DTC
S Output speed is greater than 9,762rpm.
S System voltage is too high or too low.
S CAN transmitting wiring harness shortage or open.
S TCM or ECM is defective.S Immediately after the above condition occurs.
Action Taken When The DTC Sets
S The Malfunction Indicator Lamp(MIL) will illuminate.
S The TCM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Failure Records buffer.
S Adopt Emergency/ Substitute mode and constant
4th gear.
S Open lock up clutch.
Conditions for Clearing The MIL/DTC
S The MIL will turn OFF when the malfunction has
not occurred after three–ignition cycles.
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S Using a scan tool can clear history DTCs.
Diagnostic Aids
S When DTC P0720 sets, the possible cause of fault
could be OSS(Output speed sensor).

5A1 – 104IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P0721
OUTPUT SPEED SENSOR(OSS) CIRCUIT
RANGE/PERFORMANCE
Circuit Description
The vehicle A/T OSS is a magnetic inductive pickup that
relays information relative to vehicle speed to the TCM.
Vehicle speed information is used by the TCM to control
shift timing, line pressure, and TCC apply and release.
The output speed sensor mounts in the case at the speed
sensor rotor, which is pressed onto the spur gear. An air
gap of 0.1mm~1.3mm(0.004~0.05in) is maintained be-
tween the sensor and the teeth on the spur gear teeth. The
sensor consists of a permanent magnet surrounded by a
coil of wire. As the differential rotates, an AC signal in-
duces a higher frequency and voltage measurement at the
sensor. Sensor resistance should measure
at 20°C
(68°F). Sensor can measure from 20HZ~8,000HZ.
Conditions for Setting The DTC
S Transaxle speed is less than 8,160rpm.
S The increasing rate of output speed is more than
45,000rpm/sec.
S System voltage is greater than 8.5 volts.
S Engine is running.
S No engine speed error DTCs P0727, P0725.S No transmission range sensor error DTC P0705.
S TCM or ECM is defective.
S Immediately after the above condition occurs.
Action Taken When The DTC Sets
S The Malfunction Indicator Lamp(MIL) will illuminate.
S The TCM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Failure Records buffer.
S Adopt Emergency/ Substitute mode and constant
4th gear.
S Open lock up clutch.
Conditions for Clearing The MIL/DTC
S The MIL will turn OFF when the malfunction has
not occurred after three–ignition cycles.
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S Using a scan tool can clear history DTCs.
Diagnostic Aids
S When DTC P0721 sets, the possible cause of fault
could be OSS(Output speed sensor).

ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 107
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE(DTC) P0722
OUTPUT SPEED SENSOR(OSS) CIRCUIT NO SIGNAL
Circuit Description
The vehicle A/T OSS is a magnetic inductive pickup that
relays information relative to vehicle speed to the TCM.
Vehicle speed information is used by the TCM to control
shift timing, line pressure, and TCC apply and release.
The output speed sensor mounts in the case at the speed
sensor rotor, which is pressed onto the spur gear. An air
gap of 0.1mm~1.3mm(0.004~0.05in) is maintained be-
tween the sensor and the teeth on the spur gear teeth. The
sensor consists of a permanent magnet surrounded by a
coil of wire. As the differential rotates, an AC signal in-
duces a higher frequency and voltage measurement at the
sensor. Sensor resistance should measure
at 20°C
(68°F). Sensor can measure from 20HZ~8,000HZ.
Conditions for Setting The DTC
S If the gear shift is not in progress and the selector
lever position is ”1”, ”2”, ”3”, ”D”, or ”Z3” and the
transaxle output speed is less than the limit value of
transaxle output speed for plausibility check of
transaxle output speed and the turbine speed is
greater than the limit value of turbine speed for
plausibility check of transaxle output speed then the
error bit will be set.S System voltage is greater than 7 volts.
S Engine is running.
S No input speed error DTCs P0715, P0716, and
P0717.
S No transmission range sensor error DTC P0705.
S TCM or ECM is defective.
S Immediately after the above condition occurs.
Action Taken When The DTC Sets
S The Malfunction Indicator Lamp(MIL) will illuminate.
S The TCM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Failure Records buffer.
S Vehicle running remains actual gear.
S Open lock up clutch.
Conditions for Clearing The MIL/DTC
S The MIL will turn OFF when the malfunction has
not occurred after three–ignition cycles.
S A history DTC will clear after 40 consecutive warm
up cycles without a fault.
S Using a scan tool can clear history DTCs.
Diagnostic Aids
S When DTC P0722 sets, the possible cause of fault
could be OSS(Output speed sensor).

5A1 – 236IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
ELECTRONICAL COMPONENTS
Selector Lever/Program Switch
The driver engages the travel position via the selector le-
ver:
P : Park Position
R : Reverse
N : Neutral
D : Forward Speeds
Park/Neutral Position Switch
The Park/Neutral Position Switch is located on the selec-
tor shaft and informs the TCM of the current selector lever
position P–R–N–D–3–2–1.
The selector lever position is transmitted to the TCM in en-
coded form along 4 lines. The encoding is such that mal-
functions in the connecting lead are identified.
The Park/Neutral Position Switch is located on the selec-
tor shaft, which is connected to the selector lever via a pull
cable. In addition, the Park/Neutral Position Switch con-
trols the starter interlock, the reversing light and the selec-
tor lever position indicator on the instrument panel.
Signal Combination
L1L2L3L4
P00120
R00012
N01200
D1212120
31212012
21201212
10121212
Automatic Transaxle Output Speed Sensor
(A/T OSS)
The vehicle A/T OSS is a magnetic inductive pickup that
relays information relative to vehicle speed to the TCM.
Vehicle speed information is used by the TCM to control
shift timing, line pressure, and TCC (lock–up clutch) apply
and release.
The output speed sensor mounts in the case at the speed
sensor rotor, which is pressed onto the spur gear. An air
gap of 0.1mm~1.3mm(0.004~0.05in) is maintained be-
tween the sensor and the teeth on the spur gear teeth. The
sensor consists of a permanent magnet surrounded by a
coil of wire.
As the differential rotates, an AC signal is generated by the
output speed sensor (OSS).
Automatic Transaxle Input Speed Sensor
(A/T ISS)
The A/T ISS is a magnetic inductive pickup that relays in-
formation relative to transaxle input speed to the TCM.
The TCM uses transaxle input speed information to con-
trol line pressure, TCC apply and release and transaxle
shift patterns. This information is also uses to calculate the
appropriate operating gear ratios and TCC slippage.
The input speed sensor mounts onto piston B that is inside
of valve body.
An air gap of 1.8~2.2mm(0.07~0.086inch) is maintained
between the sensor and the piston B.
The sensor consists of a permanent magnet surrounded
by a coil of wire. As the piston B is driven by the turbine
shaft, an AC signal induced in the input speed sensor.
Higher vehicle speeds induce a higher frequency and volt-
age measurement at the sensor.
Sensor resistance should measure between 825~835
ohms at 20°C (68°F). Sensor can measure from
1,000~8,000HZ.

SECTION : 7A
HEATING AND VENTILATION 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
SPECIFICATIONS7A–1 . . . . . . . . . . . . . . . . . . . . . . . . . .
Heater Temperature Specifications 7A–1. . . . . . . . . . .
Fastener Tightening Specifications 7A–1. . . . . . . . . . .
SCHEMATIC AND ROUTING DIAGRAMS7A–3 . . . . .
Non–A/C Diagrams 7A–3. . . . . . . . . . . . . . . . . . . . . . . .
Airflow – Typical 7A–4. . . . . . . . . . . . . . . . . . . . . . . . . . .
Airflow with Rear Heating Duct 7A–5. . . . . . . . . . . . . .
DIAGNOSIS7A–6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HEATER SYSTEM 7A–6. . . . . . . . . . . . . . . . . . . . . . . . . .
Insufficient Heating or Defrosting 7A–6. . . . . . . . . . . . .
Blower Electrical 7A–9. . . . . . . . . . . . . . . . . . . . . . . . . . .
Improper Air delivery or No Mode Shift 7A–11. . . . . .
Too Much Heat 7A–13. . . . . . . . . . . . . . . . . . . . . . . . . . .
Controls 7A–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Noise 7A–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . MAINTENANCE AND REPAIR7A–18 . . . . . . . . . . . . . .
ON–VEHICLE SERVICE 7A–18. . . . . . . . . . . . . . . . . . . .
Temperature Cable Adjustment 7A–18. . . . . . . . . . . . .
Temperature Control Cable 7A–18. . . . . . . . . . . . . . . . .
Control Assembly 7A–20. . . . . . . . . . . . . . . . . . . . . . . . .
Control Assembly Knob Lighting 7A–21. . . . . . . . . . . .
Heater/Air Distributor Case Assembly 7A–21. . . . . . .
Blower Motor 7A–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High–Blower Relay 7A–24. . . . . . . . . . . . . . . . . . . . . . . .
Blower Resistor 7A–25. . . . . . . . . . . . . . . . . . . . . . . . . .
Heater Hoses 7A–25. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heater Core 7A–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION7A–28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heating and Ventilation Systems 7A–28. . . . . . . . . . . .
SPECIFICATIONS
HEATER TEMPERATURE SPECIFICATIONS
Ambient Air TemperatureHeater Outlet Air Temperature
–18°C (0°F)54°C (129°F)
– 4°C (25°F)59°C (138°F)
10°C (50°F)64°C (147°F)
24°C (75°F)68°C (154°F)
FASTENER TIGHTENING SPECIFICATIONS
ApplicationNSmLb–FtLb–In
Blower Motor–to–A/C Assembly Screws1.2–11
Blower Motor Resistor Screws1.2–11
Blower Motor Retaining Screws1.2–11
Controller Retaining Screws2–18
Heater/Air Distributor Case Assembly Screw4–35