2004 DAEWOO LACETTI ignition

1F – 504IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0507
IDLE SPEED RPM HIGHER THAN DESIRED IDLE SPEED
Circuit Description
The Engine Control Module (ECM) controls the air enter-
ing into the engine with an Idle Air Control (IAC) Valve. To
increase the idle rpm, the ECM commands the pintle in-
side the IAC valve away from the throttle body seat. This
allows more air to bypass through the throttle blade. To de-
crease the rpm the ECM commands the pintle towards the
throttle body seat. This reduces the amount of air bypass-
ing the throttle blade. A scan tool will read the IAC valve
pintle position in counts. The higher the counts, the more
air that is allowed to bypass the throttle blade. This Diag-
nostic Trouble Code (DTC) determines if a high idle condi-
tion exists as defined as 200 rpm above the desired idle
rpm.
Conditions for Setting the DTC
S No intrusive tests are active.
S DTC(s) P0106, P0107, P0108, P0112, P0113,
P0117, P0118, P0122, P0123, P0131, P0132,
P0133, P0135, P0141, P1133, P1134, P0171,
P1167, P1171, P0172, P0201, P0202, P0203,
P0204, P0300, P0336, P0337, P0341, P0342,
P0351, P0352, P0402, P0404, P1404, P0405,
P0406, P0441, P0443, and P0502 are not set.
S Engine is running more than 60 seconds.
S Barometric Pressure (BARO) is greater than 72
kPa (10.4 psi).
S Engine Coolant Temperature (ECT) is greater than
60°C (140°F).
S Ignition voltage is between 11 and 16 volts.
S The Intake Air Temperature (IAT) is greater than
–20°C (–4°F).
S IAC valve is controlled fully closed.S All of the above must be met for greater than 5 sec-
onds.
S Idle engine speed error is greater than 200 rpm for
10 seconds.
Action Taken When the DTC Sets
S The Malfunction Indicator Lamp (MIL) will illuminate
after three consecutive ignition cycle with a fail.
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.
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 DTC(s) can be cleared by using the scan tool.
S Disconnecting the ECM battery feed for more than
10 seconds.
Diagnostic Aids
Inspect the IAC valve electrical connection for proper mat-
ing.
Inspect the wiring harness for damage.
Inspect the throttle stop screw for signs of tampering.
Inspect the throttle linkage for signs of binding or exces-
sive wear.
Inspect the positive crankcase ventilation (PCV) valve and
PCV hose.
A slow or unstable idle may be caused by one of the follow-
ing conditions:

ENGINE CONTROLS 1F – 505
DAEWOO V–121 BL4
S Fuel system too rich or too lean.
S Foreign material in the throttle body bore or in the
air induction system.
S A leaking or restricted intake manifold.
S Excessive engine overloading. Check for seized
pulleys, pumps, or motors on the accessory drive.
S Overweight engine oil.
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. A normally operating IAC system will be able to be
extended and retracted by a scan tool and change
the engine idle rpm. Valve movement is verified by
an engine rpm change.
3. If the scan tool was able to command the IAC valve
smoothly, a malfunction may still exist internally
within the IAC valve. This can be checked by
checking the IAC valves internal resistance.5. The IAC circuits always have ground or voltage sig-
nals on them in pairs. If the test light illuminates on
more or less than 2 terminals, 1 of the circuits is
shorted to voltage or open.
6. The IAC circuits always have ground or voltage sig-
nals on them in pairs. If the test light illuminates on
more or less than 2 terminals, 1 of the circuits is
shorted to ground or open
8. The IAC circuits are constantly switched between
ground and voltage so the test light should blink on
all circuits when connected to ground.
10. Any circuitry, that is suspected as causing the inter-
mittent complaint, should be thoroughly checked for
backed–out terminals, improper mating, broken
locks, improperly formed or damaged terminals,
poor terminal– to–wiring connections or physical
damage to the wiring harness.
12. A test light that remains ON constantly indicates
that the circuit is shorted to voltage.
14. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
16. If no malfunctions have been found at this point and
no additional DTCs were set, refer to ”Diagnostic
Aids” in this section for additional checks and infor-
mation for additional checks and information.
DTC P0507 – Idle Speed RPM Higher Than Desired Idle Speed
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. 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 command-
ed by the scan tool?900–1200 rpmGo to Step 3Go to Step 5
31. Turn the ignition OFF.
2. Disconnect the IAC valve connector.
3. Measure the resistance between terminal D
and C 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 WGo to Step 4Go to Step 13
41. Measure the resistance between terminal C
and B of the IAC valve.
2. Measure the resistance between terminal D
and A of the IAC valve.
Is the resistance equal to the specified value?–Go to Step 15Go to Step 13

1F – 506IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
51. 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 2 terminals?–Go to Step 6Go to Step 7
6With test light connected to B+, probe the IAC con-
nector terminals.
Does the test light illuminate on 2 terminals?–Go to Step 8Go to Step 9
7Check 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
81. 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 termi-
nals?–Go to Step 11Go to Step 12
9Check 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
10Check the Engine control Module (ECM) connector
for poor connections and repair as needed.
Is the repair necessary?–Go to Step 15Go to Step 14
11Inspect the IAC valve passages and repair as need-
ed.
Is the repair complete?–Go to Step 15Go to Step 13
12Check the test light.
Does the test light remain on constantly for the termi-
nals that did not blink?–Go to Step 9Go to Step 7
131. Turn the ignition OFF.
2. Replace the IAC valve.
Is the repair complete?–Go to Step 15–
141. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 15–
151. 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 16Go to Step 2
16Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to
Applicable DTC
tableSystem OK

1F – 508IENGINE CONTROLS
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–

ENGINE CONTROLS 1F – 511
DAEWOO V–121 BL4
DTC P0533 – A/C Pressure Sensor High 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–

ENGINE CONTROLS 1F – 513
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0562
SYSTEM VOLTAGE TOO LOW (ENGINE SIDE)
Circuit Description
The Engine Control Module (ECM) monitors the ignition
voltage on the ignition feed circuit to terminal K18 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 System voltage is less than 11 volts.
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.
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
If the DTC sets when an accessory is operated, check for
a poor connection or excessive current draw.
Any circuitry, that is suspected as causing the intermittent
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
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 checks if the generator is malfunctioning under
load conditions.
4. Checks the ignition feed circuit for excessive resist-
ance. An open circuit will cause a no start condi-
tion.
7. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
9. If no malfunctions have been found at this point and
no additional DTCs were set, refer to ”Diagnostic
Aids” in this section for additional checks and infor-
mation for additional checks and information.

1F – 514IENGINE CONTROLS
DAEWOO V–121 BL4
DTC P0562 – System Voltage Too Low (Engine Side)
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”
2S Install a scan tool to the Data Link Connector
(DLC) and clear the Diagnostic Trouble Codes
(DTCs).
S Start the engine and raise the engine speed
over 1400 rpm.
S Load the electrical system by turning on the
headlamps, high blower motor, etc.
Is the ignition voltage less than the specified value10 VGo to Step 3Go to Step 8
3S With the engine still running at 1400 rpm.
S Using a voltmeter measure the battery voltage
at the battery.
Is the battery voltage greater than the specified val-
ue?12 VGo to Step 4Go to
”Diagnostic
Aids”
41. Turn the ignition OFF.
2. Disconnect the Engine Control Module (ECM)
connector at the ECM.
3. Turn the ignition ON.
4. Using a voltmeter, measure the voltage at the
ignition feed circuit, terminal K18.
Is the ignition voltage greater than the specified val-
ue?10 VGo to Step 5Go to Step 6
5Check for a malfunctioning connector at the ECM
harness terminals and repair as needed.
Is the repair complete?–Go to Step 8Go to Step 7
6Repair the poor connection (high resistance) in the
ignition feed circuit.
Is the repair complete?–Go to Step 8–
71. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 8–
81. 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 9Go to Step 2
9Check 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 – 515
DAEWOO V–121 BL4
DIAGNOSTIC TROUBLE CODE (DTC) P0563
SYSTEM VOLTAGE TOO HIGH (ENGINE SIDE)
Circuit Description
The Engine Control Module (ECM) monitors the ignition
voltage on the ignition feed circuit to terminal K18 at the
ECM. A system voltage Diagnostic Trouble Code (DTC)
will set whenever the voltage is above a calibrated value.
Conditions for Setting the DTC
S System voltage is less than 16 volts.
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.
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
If the DTC sets when an accessory is operated, check for
a poor connection or excessive current draw.Any circuitry, that is suspected as causing the intermittent
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
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 checks if the generator is malfunctioning under
load conditions.
7. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
9. If no malfunctions have been found at this point and
no additional DTCs were set, refer to ”Diagnostic
Aids” in this section for additional checks and infor-
mation for additional checks and information.