2004 DAEWOO LACETTI Lamp

1F – 254IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0481
HIGH SPEED COOLING FAN RELAY CIRCUIT FAULT
(1.6L DOHC)
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 circuit to a component OFF, the
voltage potential of the circuit should be high(near battery
voltage). If the fault detection circuit senses a voltage oth-
er than what is expected, 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
S The high speed cooling fan control circuit is an
open or a short to battery or a short to ground con-
dition exist.
Action Taken When the DTC SetsS 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
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 determining
how many miles since the DTC set. The fail counter and
Pass Counter can also be used to determine how many
ignition cycles the diagnostics reported a Freeze Frame
conditions (rpm, load, vehicle speed, temperature, etc.)
that .are noted. This will isolate when the DTC failed.
DTC P0481 – High Speed Cooling Fan Relay Circuit Fault
(1.6L DOHC)
StepActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the system check complete?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to ON with the engine
OFF.
2. Install a scan tool.
3. Command the relay ON and OFF.
Does the relay turn ON and OFF when command-
ed?–Go to Step 3Go to Step 5
31. Turn the ignition switch to LOCK.
2. Disconnect the engine control module (ECM)
connector.
3. Turn the ignition switch to ON.
4. Using a digital voltmeter(DVM), measure the
current in high speed relay control circuit, at
terminal 9 to ground for 2 minutes.
Does the amperage measure less than the specified
value?0.75 ampsGo to
”Diagnostic
Aids”Go to Step 6

ENGINE CONTROLS 1F – 257
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0501
VEHICLE SPEED NO SIGNAL (M/T ONLY)
Circuit Description
Vehicle speed information is provided to the engine control
module (ECM) by the voltage speed sensor (VSS) is a per-
manent magnet generator that is mounted in the transaxle
and produces a pulsing voltage whenever vehicle speed
is over 3 mph (5km/h). The A/C voltage level and the num-
ber of pulses increase with vehicle speed. The ECM con-
verts the pulsing voltage into mph (km/h) and than sup-
plies the necessary signal to the instrument panel for
speedometer/ odometer operation and to the cruise con-
trol module and multi–function alarm module operation.
The Diagnostic Trouble Code (DTC) will detect if vehicle
speed is reasonable according to engine rpm and load.
Conditions for Setting the DTC
S Vehicle speed is not change at least 25 seconds.
S Engine speed is greater than 2,500rpm.
S MAF is greater than 180mg/tdc.
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 Failure Records
buffers.
S A history DTC is stored.
S Coolant fan turns on.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four 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 Using the scan tool can clear DTC(s).
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.
VSS signal circuit should be thoroughly checked for the
following conditions
S Backed–out terminals
S Improper mating
S Broken locks
S Improperly formed

1F – 260IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0510
THROTTLE POSITION SWITCH CIRCUIT FAULT
(1.4L DOHC)
Circuit Description
The aim of the MTIA(Main Throttle Idle Actuator) is to con-
trol the idle speed with the throttle body itself. The throttle
is motorized for low opening angle (05, 195). The charac-
teristics of the air flow are not the same for low and high
opening angles. As a matter of fact, the gradient of the
mass air flow function of TP sensor is lower for small
angles that permits to be more precise during the idle
speed control. Out of idle speed the throttle is actuated
mechanically by a classical bowdencable.
This switch indicates throttle plate in idle position when
contact closed. This switch is fixed at the DC–motor drive
and the throttle plate closes the contact in dependence to
the actual motor drive position.
Conditions for Setting the DTC
S The engine stopped and ignition switch turned ON.
S DTCs P0122, P0123, P0222 and P0223 are not
set.
S MTIA output signal is highter than throttle position +
2.5° and throttle position is open at least 0.2 sec-
onds.
Or
S DTCs P0122, P0123, P0222, and P0223 are not
set.
S The throttle position output signal is greater than
30° and throttle position is closed at least 2 sec-
onds.
Action Taken When the DTC SetsS 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.
VSS signal circuit 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 terminal to wire connection
S Physical damage to the wiring harness
Ensure the VSS is correctly torqued to the trnasaxle hous-
ing.
Refer to ”Intermittents” in this section.

1F – 262IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0510
THROTTLE POSITION SWITCH CIRCUIT FAULT
(1.6L DOHC)
Circuit Description
The aim of the MTIA(Main Throttle Idle Actuator) is to con-
trol the idle speed with the throttle body itself. The throttle
is motorized for low opening angle (05, 195). The charac-
teristics of the air flow are not the same for low and high
opening angles. As a matter of fact, the gradient of the
mass air flow function of TP sensor is lower for small
angles that permits to be more precise during the idle
speed control. Out of idle speed the throttle is actuated
mechanically by a classical bowdencable.
This switch indicates throttle plate in idle position when
contact closed. This switch is fixed at the DC–motor drive
and the throttle plate closes the contact in dependence to
the actual motor drive position.
Conditions for Setting the DTC
S The engine stopped and ignition switch turned ON.
S DTCs P0122, P0123, P0222 and P0223 are not
set.
S MTIA output signal is highter than throttle position +
2.5° and throttle position is open at least 0.2 sec-
onds.
Or
S DTCs P0122, P0123, P0222, and P0223 are not
set.
S The throttle position output signal is greater than
30° and throttle position is closed at least 2 sec-
onds.
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 Failure Records
buffers.
S A history DTC is stored.
S Coolant fan turns on.
Conditions for Clearing the MIL/DTC
S The MIL will turn off after four 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 Using the scan tool can clear DTC(s).
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.
VSS signal circuit 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 terminal to wire connection
S Physical damage to the wiring harness
Ensure the VSS is correctly torqued to the trnasaxle hous-
ing.
Refer to ”Intermittents” in this section.

1F – 264IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0532
A/C PRESSURE SENSOR LOW VOLTAGE
Circuit Description
The Air Conditioning (A/C) system uses an A/C refrigerant
pressure sensor mounted in the high pressure side of the
A/C refrigerant system to monitor A/C refrigerant pres-
sure. The Engine Control Module (ECM) uses this infor-
mation to turn ON the engine coolant fans when the A/C
refrigerant pressure is high and to keep the compressor
disengaged when A/C refrigerant pressure is excessively
high or low.
The Air Conditioning Pressure (ACP) sensor operates like
other 3–wire sensors. The ECM applies a 5.0 volt refer-
ence and a sensor ground to the sensor. Changes in the
A/C refrigerant pressure will cause the ACP sensor input
to the ECM to vary. The ECM monitors the ACP sensor
signal circuit and can determine when the signal is outside
of the possible range of the sensor. When the signal is out
of range for a prolonged period of time, the ECM will not
allow the A/C compressor clutch to engage. This is done
to protect the compressor.
Conditions for Setting the DTC
S A/C pressure is less than 12.16 kpa.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.
S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Failure Records buffers.S A history DTC is stored.
S The A/C compressor operation will be disabled
while the low voltage indication exists.
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
Inspect harness connectors for backed–out terminals, im-
proper mating, broken locks, improperly formed or dam-
aged terminals, and poor terminal–to–wire connection at
the ECM.
Inspect the wiring harness for damage. If the harness ap-
pears to be OK, observe the A/C pressure display on the
scan tool while moving the connectors and wiring har-
nesses related to the A/C Pressure sensor. A change in
the A/C pressure display will indicate the location of the
fault.
If DTC P0532 cannot be duplicated, reviewing the Fail Re-
cords vehicle mileage since the diagnostic test last failed
may help determine how often the condition that caused
the DTC to set occurs. This may assist in diagnosing the
condition.

ENGINE CONTROLS 1F – 267
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0533
A/C PRESSURE SENSOR HIGH VOLTAGE
Circuit Description
The Air Conditioning (A/C) system uses an A/C refrigerant
pressure sensor mounted in the high pressure side of the
A/C refrigerant system to monitor A/C refrigerant pres-
sure. The Engine Control Module (ECM) uses this infor-
mation to turn ON the engine coolant fans when the A/C
refrigerant pressure is high and to keep the compressor
disengaged when A/C refrigerant pressure is excessively
high or low.
The Air Conditioning Pressure (ACP) sensor operates like
other 3–wire sensors. The ECM applies a 5.0 volt refer-
ence and a sensor ground to the sensor. Changes in the
A/C refrigerant pressure will cause the ACP sensor input
to the ECM to vary. The ECM monitors the ACP sensor
signal circuit and can determine when the signal is outside
of the possible range of the sensor. When the signal is out
of range for a prolonged period of time, the ECM will not
allow the A/C compressor clutch to engage. This is done
to protect the compressor.
Conditions for Setting the DTC
S A/C pressure is greater than 293 kpa.
S Engine is running.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will not illumi-
nate.S The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Failure Records buffers.
S A history DTC is stored.
S The A/C compressor operation will be disabled
while the high voltage indication exists.
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
Inspect harness connectors for backed–out terminals, im-
proper mating, broken locks, improperly formed or dam-
aged terminals, and poor terminal–to–wire connection at
the ECM.
Inspect the wiring harness for damage. If the harness ap-
pears to be OK, observe the A/C pressure display on the
scan tool while moving the connectors and wiring har-
nesses related to the ACP sensor. A change in the A/C
pressure display will indicate the location of the fault.
If DTC P0533 cannot be duplicated, reviewing the Fail Re-
cords vehicle mileage since the diagnostic test last failed
may help determine how often the condition that caused
the DTC to set occurs. This may assist in diagnosing the
condition.

1F – 270IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0562
SYSTEM VOLTAGE(ENGINE SIDE) TOO LOW
Circuit Description
The engine control module (ECM) monitors the ignition
voltage on the ignition feed circuit to terminal 29 at the
ECM. A system voltage Diagnostic Trouble Code (DTC)
will set whenever the voltage is below a calibrated value.
Conditions for Setting the DTC
S The main relay voltage is less than 5.0v or higher
than 16.6v during 7.65 seconds. (1.4L DOHC)
S The main relay voltage is less than 5.0v or higher
than 26v during 7.6 seconds. (1.6L DOHC)
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 terminal to wiring connections
S Physical damage to the wiring harness

1F – 272IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0563
SYSTEM VOLTAGE(ENGINE SIDE) TOO HIGH
Circuit Description
The engine control module (ECM) monitors the ignition
voltage on the ignition feed circuit to terminal 29 at the
ECM. A system voltage Diagnostic Trouble Code (DTC)
will set whenever the voltage is below a calibrated value.
Conditions for Setting the DTC
S The main relay voltage is greater than 7.9V.
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/DTCS 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 terminal to wiring connections
S Physical damage to the wiring harness