display DAEWOO LACETTI 2004 Service Workshop Manual

ENGINE CONTROLS 1F – 255
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
41. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Using a DVM, measure the resistance between
terminals 85 and 9 in the high speed cooling
fan relay control circuit in the ECM harness
connector to ground.
Does the DVM display infinite resistance?–Go to Step 12Go to Step 10
51. Turn the ignition switch to LOCK.
2. Disconnect the relay.
3. Connect a test light between the relay coil ter-
minals 86 and 85 in the relay harness connec-
tor.
4. Turn the Turn the ignition switch to ON.
5. Using the scan tool, command the relay ON
and OFF.
Does the test light turn ON and OFF with each com-
manded?–Go to Step 8Go to Step 6
6With the test light connected to ground, probe the
ignition feed circuit in the relay harness connector.
Does the test light illuminate?–Go to Step 7Go to Step 11
71. Turn the ignition switch to LOCK.
2. Reconnect the relay.
3. Disconnect the ECM connector containing the
relay control circuit.
4. Turn the Turn the ignition switch to ON.
5. With a fused jumper wire connected to ground,
probe the relay control circuit at terminal 9 in
the ECM harness connector.
Does the relay operate?–Go to Step 9Go to Step 10
8Check the connections at the relay.
Is a problem found and corrected?–Go to Step 14Go to Step 12
9Check the connection at the ECM.
Is a problem found and corrected?–Go to Step 11Go to Step 13
10Repair the faulty relay control circuit.
Is the repair complete?–Go to Step 14–
11Repair the faulty relay ignition feed circuit.
Is the repair complete?–Go to Step 14–
12Replace the relay.
Is the replacement complete?–Go to Step 14–
13Replace the ECM.
Is the replacement complete?–Go to Step 14–

1F – 256IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
141. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 15Go to Step 2
15Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 258IENGINE CONTROLS
DAEWOO V–121 BL4
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.
DTC P0501 – Vehicle Speed No Signal (M/T Only)
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”
2Notice : Running the vehicle in gear with the wheels
hanging down at full travel will damage the drive
axles.
1. Turn the ignition ON, with the engine OFF.
2. Install a scan tool.
3. Raise the drive wheels.
4. Support the lower control arms so that the
drive axles are in a horizontal (straight) posi-
tion.
5. Allow the engine to idle in gear.
Does the scan tool display vehicle speed above the
specified value?0 mphGo to Step 3Go to Step 4
31. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data and note the
parameters.
3. Operate the vehicle within the Freeze Frame
conditions and Conditions for Setting this DTC.
Does the scan tool display the vehicle speed above
the specified value?0 mphGo to Step 12Go to Step 4
41. Turn the ignition OFF.
2. Disconnect the engine control module(ECM)
connector 51.
3. Using a digital voltmeter(DVM) connected to
ground, measure the voltage in the Vehicle
Speed Sensor (VSS) signal circuit, at terminal
C while rotating the wheels.
Is the voltage greater than or eqaul to specified val-
ue?0.5VGo to Step 12Go to Step 5
5Measure the resistant in the VSS signal circuit while
rotating the wheels.
Is the resistance greater than the specified value?1950WGo to Step 6Go to Step 7
6Check the VSS signal circuit for an open and repair
as necessary.
Is the repair complete?–Go to Step 12Go to Step 9
7Is the resistance value within or equal to the speci-
fied value?1300–1950WGo to Step 8Go to Step 9
8Check the VSS signal circuit for a short to ground or
for being shorted together and repair as necessary.
Is a repair necessary?–Go to Step 12Go to Step 12
91. Remove the VSS.
2. Measure the resistance between terminals A
and C.
Is the resistance value within the specified value?1300–1950WGo to Step 11Go to Step 10

ENGINE CONTROLS 1F – 259
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
10Replace the VSS.
Is the action complete?–Go to Step 12–
11Replace the ECM.
Is the action complete?–Go to Step 12–
121. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 13Go to Step 2
13Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 261
DAEWOO V–121 BL4
DTC P0510 – Throttle Position Switch Circuit Fault (1.4L 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 LOCK.
2. Disconnect the MTIA connector.
3. Disconnect the ECM connector.
4. Check for a short to ground or open in the wire
between the MTIA connector terminal 6 and
ECM connector terminal 55.
Is the problem found?–Go to Step 4Go to Step 3
3Check for a high voltage or open in the wire between
the MTIA connector terminal 6 and ECM connector
terminal 55.
Is the problem found?–Go to Step 4Go to Step 5
41. Turn the ignition switch to LOCK.
2. Repair the wire or the connector terminal as
needed.
3. Clear any DTCs from ECM.
4. Perform the diagnostic system check.(start en-
gine and turn LOCK).
Is the repair complete?–System OK–
51. Repair the short to battery voltage or ground in
the wire between the EVAP canister purge
valve connector terminal 2 and the ECM con-
nector terminal 79.
2. Clear any Diagnostic Trouble Codes (DTCs)
from the ECM.
3. Perform the diagnostic system check.
Is the repair complete?–Go to Step 6–
61. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 7Go to Step 2
7Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

ENGINE CONTROLS 1F – 263
DAEWOO V–121 BL4
DTC P0510 – Throttle Position Switch 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 LOCK.
2. Disconnect the MTIA connector.
3. Disconnect the ECM connector.
4. Check for a short to ground or open in the wire
between the MTIA connector terminal 6 and
ECM connector terminal 55.
Is the problem found?–Go to Step 4Go to Step 3
3Check for a high voltage or open in the wire between
the MTIA connector terminal 6 and ECM connector
terminal 55.
Is the problem found?–Go to Step 4Go to Step 5
41. Turn the ignition switch to LOCK.
2. Repair the wire or the connector terminal as
needed.
3. Clear any DTCs from ECM.
4. Perform the diagnostic system check.(start en-
gine and turn LOCK).
Is the repair complete?–System OK–
51. Repair the short to battery voltage or ground in
the wire between the EVAP canister purge
valve connector terminal 2 and the ECM con-
nector terminal 79.
2. Clear any Diagnostic Trouble Codes (DTCs)
from the ECM.
3. Perform the diagnostic system check.
Is the repair complete?–Go to Step 6–
61. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the conditions for
setting the DTC as specifiec in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 7Go to Step 2
7Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

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 – 265
DAEWOO V–121 BL4
DTC P0532 – A/C Pressure Sensor Low Voltage
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. Install a scan tool to the Data Link Connector
(DLC).
2. Idle the engine.
Does the scan tool display Air Conditioning Pressure
(ACP) sensor voltage below the specified value?0.06 VGo to Step 3Go to Step 4
31. Turn the ignition OFF.
2. Disconnect the ACP sensor connector.
3. Jumper the ACP signal circuit, terminal 2 to the
5 volt reference circuit, terminal 1.
4. Turn the ignition switch on.
Does the ACP voltage read more than the specified
value?4.9 VGo to Step 5Go to Step 6
41. Turn the ignition ON, with the engine OFF.
2. Operate the vehicle within the Failure Record
conditions and Conditions For Setting the DTC
as noted.
Does the scan tool display ACP voltage below the
specified value?0.06 VGo to Step 3Go to
”Diagnostic
Aids”
5Inspect the ACP sensor harness connector termi-
nals for the following conditions:
S Poor connections
S Proper contact tension
S Poor terminal–to–wire connection
Is a problem found?–Go to Step 8Go to Step 9
61. Turn the ignition OFF.
2. Remove the jumper wire.
3. Probe the ACP sensor signal circuit terminal 2
with a test light to B+.
4. Turn the ignition ON.
Does the scan tool read over the specified value?4 VGo to Step 7Go to Step 11
7Check the ACP sensor 5 volt reference circuit for an
open or short to ground and repair as needed.
Is the repair complete?–Go to Step 13Go to Step 10
8Repair the connection terminals as necessary.
Is the repair complete?–Go to Step 13–
91. Turn the ignition OFF.
2. Replace the ACP sensor.
Is the repair complete?–Go to Step 13–
101. Turn the ignition OFF.
2. Replace the engine control module (ECM).
Is the repair complete?–Go to Step 13–

1F – 266IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
11Check the ACP sensor signal circuit for the following
conditions:
S Open
S Short to ground
S Short to sensor ground
Is a problem found?–Go to Step 12Go to Step 10
12Repair the A/C Pressure sensor signal circuit.
Is the repair complete?–Go to Step 13–
131. Using the scan tool, clear the Diagnostic
Trouble Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
3. Operate the vehicle within the Conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?–Go to Step 14Go to Step 2
14Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

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.