1F–48 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F090
ENGINE COOLING FAN CIRCUIT CHECK
Circuit Description
The engine cooling fan circuit operates the cooling fan.
The cooling fan is controlled by the engine control mod-
ule (ECM) based on input from the coolant temperature
sensor (CTS) and the A/C ON/OFF. The ECM controls
the low speed cooling fan operation by internally ground-
ing the ECM connector terminal 39. This energizes the
low speed cooling fan relay and operates the cooling fan
at low speed. The low speed cooling fan operation is
achieved by the cooling fan resistor causing a drop in
the voltage supplied to the cooling fan. The ECM con-
trols the high speed cooling fan operation by internally
grounding the ECM connector terminal 5. This ener-
gizes the high speed cooling fan relay, bypassing the ra-
diator fan resistor. This results in high speed cooling fan
operation.
Diagnostic Aids
If the owner complained of an overheating problem, it
must be determined if the complaint was due to anactual boil over, or the engine coolant temperature
gauge indicated overheating. If the engine is over-
heating and the cooling fans are on, the cooling sys-
tem should be checked.
If the engine fuse block fuse EF15 become open
(blown) immediately after installation, inspect for a
short to ground in the wiring of the appropriate circuit.
If the fuse become open (blown) when the cooling
fans are to be turned on by the Engine Control Mod-
ule (ECM), suspect a faulty cooling fan motor.
The ECM will turn the cooling fan on at low speed
when the coolant temperature is 93C (199F). The
ECM will turn the cooling fans off when the coolant
temperature is 90C (194F).
The ECM will turn the cooling fans on at high speed
when the coolant temperature is 100C (212F). The
ECM will change the cooling fans from high speed to
low speed when the coolant temperature is 97C
(207F).
1F–226 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F090
DIAGNOSTIC TROUBLE CODE (DTC) – P0480 LOW SPEED COOLING FAN
RELAY CIRCUIT FAULT (WITHOUT A/C)
Circuit Description
Ignition voltage is supplied directly to the cooling fan
relay coil. The engine control module(ECM) controls the
relay by grounding the control circuit via an internal
switch called a driver. The primary function of the driver
is supply the ground for the component being controlled.
Each driver has a fault line which is monitored by the
ECM. When the ECM is commanding a component ON,
the voltage of the control circuit should be low (near
0volts). When the ECM is commanding the control cir-
cuit to a component OFF, the voltage potential of the cir-
cuit should be high(near battery voltage). If the fault
detection circuit senses a voltage other than what is ex-
pected, the fault line status will change causing the DTC
to set.
The relay is used to control the high current flow to the
cooling fan motors. This allows the ECM driver to only
have to handle the relatively low current used by the
relay.
Conditions for Setting the DTC
Diagnostic Trouble Codes (DTCs) P0117, P0118 not
set.
Ignition ON.Ignition voltage is greater than 10 volts.
Engine run time is greater than 5 seconds.
Action Taken When the DTC Sets
The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
The ECM will store conditions which were present
when the DTC was set as Failure Records data only.
This information will not be stored in the Freeze
Frame data.
Conditions for Clearing the MIL/DTC
A history DTC will clear after 40 consecutive warm-up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
Using Freeze Frame and/or failure records data may aid
in locating an intermittent condition. If the DTC cannot
be duplicated, the information included in the Freeze
Frame and/or failure records data can be useful in deter-
mining how many miles since the DTC set. The fail
counter and Pass Counter can also be used to deter-
mine how many ignition cycles the diagnostics reported
1F–230 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F270
DIAGNOSTIC TROUBLE CODE (DTC) – P0480 LOW SPEED COOLING FAN
RELAY CIRCUIT FAULT (WITH A/C)
Circuit Description
Ignition voltage is supplied directly to the cooling fan
relay coil. The engine control module(ECM) controls the
relay by grounding the control circuit via an internal
switch called a driver. The primary function of the driver
is supply the ground for the component being controlled.
Each driver has a fault line which is monitored by the
ECM. When the ECM is commanding a component ON,
the voltage of the control circuit should be low (near
0volts). When the ECM is commanding the control cir-
cuit to a component OFF, the voltage potential of the cir-
cuit should be high(near battery voltage). If the fault
detection circuit senses a voltage other than what is ex-
pected, the fault line status will change causing the DTC
to set.
The relay is used to control the high current flow to the
cooling fan motors. This allows the ECM driver to only
have to handle the relatively low current used by the
relay.
Conditions for Setting the DTC
Diagnostic Trouble Codes (DTCs) P0117, P0118 not
set.
Ignition ON.Ignition voltage is greater than 10 volts.
Engine run time is greater than 5 seconds.
Action Taken When The DTCs Sets
The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
The ECM will store conditions which were present
when the DTC was set as Failure Records data only.
This information will not be stored in the Freeze
Frame data.
Conditions for Clearing the MIL/DTC
A history DTC will clear after 40 consecutive warm-up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
Using Freeze Frame and/or failure records data may aid
in locating an intermittent condition. If the DTC cannot
be duplicated, the information included in the Freeze
Frame and/or failure records data can be useful in deter-
mining how many miles since the DTC set. The fail
counter and Pass Counter can also be used to deter-
mine how many ignition cycles the diagnostics reported
1F–234 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F090
DIAGNOSTIC TROUBLE CODE (DTC) – P0481 HIGH SPEED COOLING FAN
RELAY CIRCUIT FAULT (WITHOUT A/C)
Circuit Description
Ignition voltage is supplied directly to the cooling fan
relay coil. The engine control module(ECM) controls the
relay by grounding the control circuit via an internal
switch called a driver. The primary function of the driver
is supply the ground for the component being controlled.
Each driver has a fault line which is monitored by the
ECM. When the ECM is commanding a component ON,
the voltage of the control circuit should be low (near
0volts). When the ECM is commanding the control cir-
cuit to a component OFF, the voltage potential of the cir-
cuit should be high(near battery voltage). If the fault
detection circuit senses a voltage other than what is ex-
pected, the fault line status will change causing the DTC
to set.
The relay is used to control the high current flow to the
cooling fan motors. This allows the ECM driver to only
have to handle the relatively low current used by the
relay.
Conditions for Setting the DTC
Diagnostic Trouble Codes (DTCs) P0117, P0118 not
set.
Ignition ON.Ignition voltage is greater than 10 volts.
Engine run time is greater than 5 seconds.
Action Taken When The DTCs Sets
The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
The ECM will store conditions which were present
when the DTC was set as Failure Records data only.
This information will not be stored in the Freeze
Frame data.
Conditions for Clearing the MIL/DTC
A history DTC will clear after 40 consecutive warm-up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
Using Freeze Frame and/or failure records data may aid
in locating an intermittent condition. If the DTC cannot
be duplicated, the information included in the Freeze
Frame and/or failure records data can be useful in deter-
mining how many miles since the DTC set. The fail
counter and Pass Counter can also be used to deter-
mine how many ignition cycles the diagnostics reported
1F–238 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F270
DIAGNOSTIC TROUBLE CODE (DTC) – P0481 HIGH SPEED COOLING FAN
RELAY CIRCUIT FAULT (WITH A/C)
Circuit Description
Ignition voltage is supplied directly to the cooling fan
relay coil. The engine control module(ECM) controls the
relay by grounding the control circuit via an internal
switch called a driver. The primary function of the driver
is supply the ground for the component being controlled.
Each driver has a fault line which is monitored by the
ECM. When the ECM is commanding a component ON,
the voltage of the control circuit should be low (near
0volts). When the ECM is commanding the control cir-
cuit to a component OFF, the voltage potential of the cir-
cuit should be high(near battery voltage). If the fault
detection circuit senses a voltage other than what is ex-
pected, the fault line status will change causing the DTC
to set.
The relay is used to control the high current flow to the
cooling fan motors. This allows the ECM driver to only
have to handle the relatively low current used by the
relay.
Conditions for Setting the DTC
Diagnostic Trouble Codes (DTCs) P0117, P0118 not
set.
Ignition ON.Ignition voltage is greater than 10 volts.
Engine run time is greater than 5 seconds.
Action Taken When The DTCs Sets
The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
The ECM will store conditions which were present
when the DTC was set as Failure Records data only.
This information will not be stored in the Freeze
Frame data.
Conditions for Clearing the MIL/DTC
A history DTC will clear after 40 consecutive warm-up
cycles without a fault.
DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
Using Freeze Frame and/or failure records data may aid
in locating an intermittent condition. If the DTC cannot
be duplicated, the information included in the Freeze
Frame and/or failure records data can be useful in deter-
mining how many miles since the DTC set. The fail
counter and Pass Counter can also be used to deter-
mine how many ignition cycles the diagnostics reported
ENGINE CONTROLS 1F–247
DAEWOO M-150 BL2
Excessive engine overloading. Check for seized pul-
leys, pumps, or motors on the accessory drive,Overweight engine oil.
DTC P0505 Idle Air Control Valve (IACV) Circuit Fault
StepActionValue(s)YesNo
1
Perform an On-Board Diagnostic (EOBD) System
Check.
Was the check performed?
–
Go to Step 2
Go to
“On-Board
Diagnostic
System Check”
2
1. Install a scan tool to the Data Link Connector
(DLC).
2. Operate the engine to idle speed.
3. Transmission in park or neutral and the parking
brake set.
4. A/C is off.
5. Using scan tool, command the Idle Air Control
(IAC) valve up and down between the specified
value.
Does the rpm change smoothly when he
commanded by the scan tool?
900–1200
rpm
Go to Step 3Go to Step 5
3
1. Turn the ignition OFF.
2. Disconnect the IAC valve connector.
3. Measure the resistance between terminal C and
D of the IAC valve.
4. Measure the resistance between terminal B and A
of the IAC valve.
Is the resistance within the specified value?
40–80 ΩGo to Step 4Go to Step 13
4
1. Measure the resistance between terminal D and
B of the IAC valve.
2. Measure the resistance between terminal C and
A of the IAC valve.
Is the resistance equal to the specified value?
∞Go to Step 15Go to Step 13
5
1. Turn the ignition OFF.
2. Disconnect the IAC valve connector.
3. Turn the ignition ON.
4. With test light connected to ground, probe the
IAC connector terminals.
Does the test light illuminate on D terminals?
–
Go to Step 6Go to Step 7
6
With test light connected to B+, probe the IAC
connector terminals.
Does the test light illuminate on D terminals?
–
Go to Step 8Go to Step 9
7
Check for an open or short to ground in the IAC high
and low circuits and repair as needed.
Is the repair complete?
–
Go to Step 15Go to Step 10
8
1. Idle the engine.
2. Connect a test light to ground, probe the IAC
connector terminals.
Does the test light flash On and OFF for all
terminals?
–
Go to Step 11Go to Step 12
9
Check for an open or a short to voltage in the IAC
valve high and low circuits and repair as needed.
Is the repair complete?
–
Go to Step 15Go to Step 10
10
Check the Engine control Module (ECM) connector
for poor connections and repair as needed.
Is the repair complete?
–
Go to Step 15Go to Step 14
4D – 2 FRONT DISC BRAKES
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
DISC BRAKE CALIPER ASSEMBLY
This caliper has a single bore and is mounted to the
steering knuckle with two mounting bolts. Hydraulic
pressure, created by applying the brake pedal, is con-
verted by the caliper to a stopping force. This force acts
equally against the piston and the bottom of the caliper
bore to move the piston outward and to slide the caliper
inward, resulting in a clamping action on the rotor. This
clamping action forces the linings against the rotor,
creating friction to stop the vehicle.
D17B001A
Important:
Replace all components included in the repair kits
used to service this caliper.
Lubricate the rubber parts with clean brake fluid to
ease assembly.
Do not use lubricated shop air on brake parts, as
damage to the rubber components may result.
If any hydraulic component is removed or discon-
nected, it may be necessary to bleed all or part of the
brake system.
Replace the pads in axle sets only.
The torque values specified are for dry, unlubricated
fasteners.
Perform the service operations on a clean bench, free
from all mineral oil materials.
CLEARANCE CALIBRATION
When the hydraulic pressure is applied to the piston, the
piston moves leftward. The piston seal, which extent
considerable pressure against the piston, moves with
cylinder.
However, as a part of the piston seal is fixed into a grove
in the cylinder shape of the seal is as shown in below
figure, distorted toward the piston moving direction.
When the pressure is taken off from the brake pedal and
the hydraulic pressure is released from the piston, a re-
storing elastic force is generated at the seal and pushes
the piston rightward and back it in original position.
As the pads wear away and the clearance between rotor
and pads becomes larger, the piston moves larger.
The seal then could change in shape further, but since
end of the seal is fixed into the groove in the cylinder, the
distortion is limited to the same amount as previously
described.
The piston moves further to cover the distance of clear-
ance. As the piston returns by the same distance and
the rubber seal recovers its original shape, the clear-
ance between the rotor and pads is maintained in origi-
nal condition.
1. Piston
2. Piston Seal
3. Pads
a. Clearance
D107B002
7B–2 MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
SYSTEM COMPONENTS
–FUNCTIONAL
Compressor
All compressors are belt–driven from the engine crank-
shaft through the compressor clutch pulley. The com-
pressor pulley rotates without driving the compressor
shaft until on electromagnetic clutch coils energized.
When voltage is applied to energize the clutch coil, the
clutch plate and hub assembly are drawn toward the
pulley. The magnetic force locks the clutch plate and
pulley together as one unit to drive the compressor
shaft.
Condenser Core
The condenser assembly in front of the radiator consists
of coils which carry the refrigerant and cooling fins that
provide the rapid transfer of heat. The air passing
through the condenser cools the high–pressure refriger-
ant vapor and cause it to condense into a liquid.
Expansion Valve
The expansion valve is located on the passenger
compartment side of the dash panel. The expansion
valve can fail in three different positions: open, closed,
or restricted. An expansion valve that fails in the open
position will result in a noisy A/C compressor or no cool-
ing. The cause can be a broken spring, a broken ball, or
excessive moisture in the A/C system. If the spring or
the ball is found to be detective, replace the expansion
valve. If excessive moisture is found in the A/C system,
recycle the refrigerant. An expansion valve that fails in
the closed position will result in low suction pressure and
no cooling. This may be caused by a failed power done
or excessive moisture in the A/C system. If the power
dome on the expansion valve is found to be defective,
replace the expansion valve. If excessive moisture is
found in the A/C system, recycle the refrigerant.
A restricted expansion valve will result in low suction
pressure and no cooling. This may be caused by debrisin the refrigerant system. If debris is believed to be
cause, recycle the refrigerant, replace the expansion
valve, and replace the receiver/dryer.
Evaporator Core
The evaporator is device which cools and dehumidifies
the air before it enters the vehicle. High–pressure liquid
refrigerant flows through the expansion tube (orifice)
and becomes a low–pressure gas in the evaporator. The
heat in the air passing through the evaporator core is
transferred to the cooler surface of the core, which cools
the air. As the process of heat transfer from the air to the
evaporator core surface is taking place, any moisture
(humidity) in the air condenses on the outside surface of
the evaporator core and is drained off as water.
Receiver–Dryer
The sealed receiver–dryer assembly is connected to the
evaporator outlet pipe. It acts as a refrigerant storing
container, receiving liquid and some vapor and refriger-
ant oil from the evaporator.
At the bottom the receiver–dryer is the desiccant, which
acts as a drying agent for the moisture that may have
entered the system. The receiver–dryer is serviceable
only as an assembly.
Dual Cut Switch
The dual cut switch controls compressor operation when
the cycling refrigerant pressure is dropped or surged.
Evaporator Thermistor
A semiconductor which resistance is noticeably changed
as the change of temperature. When the refrigerant tem-
perature of the evaporator drops to 0C (32F) and be-
low, the evaporator cores get stuck with frost or ice,
reducing the airflow, lowering the cooling capacity. The
thermistor is a sensor which is used to prevent from frost-
ing or icing.
The thermistor is installed on the evaporator.