1F – 36IENGINE CONTROLS
DAEWOO V–121 BL4
MULTIPLE ECM INFORMATION SENSOR DTCS SET
Circuit Description
The Engine Control Module (ECM) monitors various sen-
sors to determine engine operating conditions. The ECM
controls fuel delivery, spark advance, transaxle operation,
and emission control device operation based on the sen-
sor inputs.
The ECM provides a sensor ground to all of the sensors.
The ECM applies 5 volts through a pull–up resistor and
monitors the voltage present between the sensor and the
resistor to determine the status of the Engine Coolant
Temperature (ECT) sensor, the Intake Air Temperature
(IAT) sensor. The ECM provides the Exhaust Gas Recir-
culation (EGR) Pintle Position Sensor, the Throttle Posi-
tion (TP) sensor, the Manifold Absolute Pressure (MAP)
sensor, and the Fuel Tank Pressure Sensor with a 5 volt
reference and a sensor ground signal. The ECM monitors
the separate feedback signals from these sensors to de-
termine their operating status.
Diagnostic Aids
Be sure to inspect the ECM and the engine grounds for be-
ing secure and clean.
A short to voltage in one of the sensor circuits can cause
one or more of the following DTCs to be set: P0108,
P0113, P0118, P0123, P1106, P1111, P1115, P1121,
P0463, P0533.
If a sensor input circuit has been shorted to voltage, en-
sure that the sensor is not damaged. A damaged sensor
will continue to indicate a high or low voltage after the af-
fected circuit has been repaired. If the sensor has been
damaged, replace it.
An open in the sensor ground circuit between the ECM and
the splice will cause one or more of the following DTCs to
be set: P0107, P0108, P0113, P0118, P0122, P0123,
P1106, P1111, P1115, P1121, P0462, P0532.
A short to ground in the 5 volt reference circuit or an open
in the 5 volt reference circuit between the ECM and the
splice will cause one or more of the following DTCs to be
set: P0107, P0112, P0117, P0122, P1107, P1112, P1114,
P1122, P0462, P0532.Check for the following conditions:
S Inspect for a poor connection at the ECM. Inspect
harness connectors for backed–out terminals, im-
proper mating, broken locks, improperly formed or
damaged terminals, and poor terminal–to–wire con-
nection.
S Inspect the wiring harness for damage. If the har-
ness appears to be OK, observe an affected sen-
sor ’s displayed value on the scan tool with the igni-
tion ON and the engine OFF while moving
connectors and wiring harnesses related to the af-
fected sensors. A change in the affected sensor’s
displayed value will indicate the location of the fault.
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.
1. The Powertrain On–Board Diagnostic (EOBD) Sys-
tem Check prompts the technician to complete
some basic checks and store the freeze frame and
failure records 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.
9. A faulty EGR valve can leak a small amount of cur-
rent from the ignition feed circuit to the 5 volt refer-
ence circuit. If the problem does not exist with the
EGR valve disconnected, replace the EGR valve.
0. If a sensor input circuit has been shorted to voltage,
ensure that the sensor has not been damaged. A
damaged IAT or ECT sensor will continue to indi-
cate a high voltage or low temperature after the
affected circuit has been repaired. A damaged ACT,
TP, MAP, Fuel Tank Pressure, or EGR Pintle Posi-
tion sensor will indicate a high or low voltage or
may be stuck at a fixed value after the affected cir-
cuit has been repaired. If the sensor has been dam-
aged, replace it.
21. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.
ENGINE CONTROLS 1F – 37
DAEWOO V–121 BL4
Multiple ECM Information Sensor DTCs Set
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) system
check.
Is the check complete.–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to LOCK.
2. Disconnect the Engine Control Module (ECM)
connector.
3. Turn the ignition switch to ON.
4. Check the 5V reference circuit for the following
conditions:
S Poor connection at the ECM.
S Open between the ECM connector affected
sensors shorted to ground or voltage.
5. If a problem is found, locate and repair the
open or short circuit as needed.
Is a problem found?–Go to Step 19Go to Step 3
31. Check the sensor ground circuit for the follow-
ing conditions:
S Poor connection at the ECM or affected
sensors.
S Open between the ECM connector and the
affected sensors.
2. If a problem is found, repair it as needed.
Is a problem found?–Go to Step 19Go to Step 4
4Measure the voltage of the Exhaust Gas Recircula-
tion (EGR) Pintle Position Sensor signal circuit be-
tween ECM harness connector and ground.
Does the voltage near the specified value?0 VGo to Step 5Go to Step 9
5Measure the voltage of the Manifold Absolute Pres-
sure (MAP) sensor signal circuit between the ECM
harness connector and ground.
Does the voltage near the specified value?0 VGo to Step 6Go to Step 12
6Measure the voltage of the Throttle Position (TP)
sensor signal circuit between the ECM harness con-
nector and ground.
Does the voltage near the specified value?0 VGo to Step 7Go to Step 12
7Measure the voltage of the Intake Air Temperature
(IAT) sensor signal circuit between the ECM har-
ness connector and ground.
Does the voltage near the specified value?0 VGo to Step 8Go to Step 13
8Measure the voltage of the Engine Coolant Temper-
ature (ECT) sensor signal circuit between the ECM
harness connector and ground.
Does the voltage near the specified value?0 VGo to Step 16Go to Step 14
91. Disconnect the EGR valve connector.
2. Measure the voltage of the EGR Pintle Position
sensor signal circuit between the ECM harness
connector and ground.
Does the voltage near the specified value?0 VGo to Step 10Go to Step 15
1F – 38IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
10Replace the EGR valve.
Is the replacement complete?–Go to Step 19–
11Locate and repair the short to voltage in the MAP
sensor signal circuit.
Is the repair complete?–Go to Step 19–
12Locate and repair the short to voltage in the TP sen-
sor signal circuit.
Is the repair complete?–Go to Step 19–
13Locate and repair the short to voltage in the IAT sen-
sor signal circuit.
Is the repair complete?–Go to Step 19–
14Locate and repair the short to voltage in the ECT
sensor signal circuit.
Is the repair complete?–Go to Step 19–
15Locate and repair the short to voltage in the EGR
Pintle Position sensor circuit.
Is the repair complete?–Go to Step 19–
16Measure the voltage of the fuel tank pressure sensor
signal circuit between the ECM harness connector
and ground.
Does the voltage near the specified value?0 VGo to Step 18Go to Step 17
17Locate and repair the short to voltage in the fuel tank
pressure sensor signal circuit.
Is the replacement complete?–Go to Step 19–
18Replace the ECM.
Is the repair complete?–Go to Step 19
191. 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 DTCs as specified in the supporting
text.
Does the scan tool indicate that this diagnostic ran
and passed?–Go to Step 20Go to Step 2
22Check if any additional DTCs are set.
Are any DTCs displayed that have not been diag-
nosed?–Go to applica-
ble DTC tableSystem OK
ENGINE CONTROLS 1F – 39
DAEWOO V–121 BL4
1F – 40IENGINE CONTROLS
DAEWOO V–121 BL4
ENGINE CRANKS BUT WILL NOT RUN (1.4L/1.6L DOHC)
Test Description
The number(s) below refer to step(s) on the diagnostic
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 occurred. The information is then stored on the
scan tool for later reference.
2. By performing a compression test, it can be deter-
mined if the engine has the mechanical ability to
run.
3. It is important to check for the presence of sparkfrom all of the ignition wires. If spark is present from
one to three of the ignition coil terminals, the Crank-
shaft Position (CKP) sensor is OK.
19. In checking the engine control module (ECM) out-
puts for the electronic spark timing signal, it recom-
mended to use an oscilloscope to view the varying
voltage signals. In measuring these outputs with a
voltmeter, intermittent errors may occur that cannot
be seen by a voltmeter.
35. This step checks for proper operation of the ECM’s
control of the fuel pump circuit.
59. This step checks for a ground signal being supplied
by the ECM to operate the fuel injectors. If there is
no ground present during the cranking of the en-
gine, and the fuel injector wiring is OK, the ECM is
at fault.
Engine Cranks But Will Not Run (1.4L/1.6L DOHC)
CAUTION : Use only electrically insulated pliers when
handling ignition wires with the engine running to
prevent an electrical shock.
CAUTION : Do not pinch or restrict nylon fuel lines.Damage to the lines could cause a fuel leak, resulting
in possible fire or personal injury.
Step
ActionValue(s)YesNo
1Perform an Euro On–Board Diagnostic (EOBD)
System Check.
Is the check complete.–Go to Step 2Go to
”Euro On–
Board Diagnos-
tic System
Check”
2Crank the engine.
Does the engine start and continue to run?–System OKGo to Step 3
3Perform a cylinder compression test.
Is the cylinder compression for all of the cylinders at
or above the value specified?689 kPa
(100 psi)Go to Step 7Go to Step 4
4Inspect the timing belt alignment.
Is the timing belt in alignment?–Go to Step 6Go to Step 5
5Align or replace the timing belt as needed.
Is the repair complete?–Go to Step 2–
6Repair internal engine damage as needed.
Is the repair complete?–Go to Step 2–
7Inspect the fuel pump fuse.
Is the problem found?–Go to Step 8Go to Step 9
8Replace the fuse.
Is the repair complete?–Go to Step 2–
9Check for the presence of spark from all of the igni-
tion wires while cranking the engine.
Is spark present from all of the ignition wires?–Go to Step 23Go to Step 10
101. Measure the resistance of the ignition wires.
2. Replace any of the ignition wire(s) with a resist-
ance above the value specified.
3. Check for the presence of spark from all of the
ignition wire.
Is spark present from all of the ignition wires?30000 WGo to Step 2Go to Step 11
ENGINE CONTROLS 1F – 41
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Turn the ignition OFF.
2. Disconnect the crankshaft position (CKP) sen-
sor connector.
3. Turn the ignition ON.
4. Measure the voltage between following termi-
nals:
S Terminal 1 and 3 of the CKP sensor con-
nector.
S Terminal 2 and 3 of the CKP sensor con-
nector.
S Terminal 1 of the CKP sensor connector
and ground.
S Terminal 2 of the CKP sensor connector
and ground.
Are the voltage measure within the value specified? 1.4 VGo to Step 13Go to Step 12
12Check for an open or short in the wires between CKP
sensor connector and ECM connector and repair as
need.
Is the repair complete?–Go to Step 2–
131. Disconnect electronic Ignition (EI) system igni-
tion coil connector to prevent the vehicle from
starting.
2. Measure the voltage at ECM connector termi-
nal 85 and 54 by backprobing the ECM con-
nector.
Are the voltage readings near the value specified?1.4V with
ignition ON,
1.6V during
crankingGo to Step 15Go to Step 14
14Replace the CKP sensor.
Is the repair complete?–Go to Step 2–
151. Turn the ignition OFF.
2. Disconnect the electrical connector at EI sys-
tem ignition coil.
3. Connect a test light between terminal 2 of the
EI system ignition coil connector and ground.
4. Turn the ignition ON.
Is the test light on?–Go to Step 17Go to Step 16
16Check for open in wire between the battery and EI
system ignition coil connector terminal 2 and repair
as needed.
Is the repair complete?–Go to Step 2–
171. Turn the ignition OFF.
2. Disconnect ECM connect and EI system igni-
tion coil connector.
3. Measure the resistance between following ter-
minals:
S Terminal 1 of ignition coil and terminal 31 of
ECM connector.
S Terminal 1 of ignition coil and terminal 32 of
ECM connector.
Are the resistance within the value specified?0 WGo to Step 19Go to Step 18
18Check for open circuit and repair as needed.
Is the repair complete?–Go to Step 2–
1F – 42IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
191. Measure the resistance between following ter-
minals:
S Terminal 1 and 2 of ignition coil.
S Terminal 2 and 1 of ignition coil.
Are the resistance within the value specified.
1. Remove the high tension cable.
2. Measure the resistance between second coil.
S Between 1 and 4
S Between 2 and 3
Are the resistance within the value specified.0.9 W
5.3 kWGo to Step 21Go to Step 20
20Replace the EI system ignition coil.
Is the repair complete?–Go to Step 2–
211. Check for any damages or poor connection in
ignition wires and repair as needed.
2. Connect the EI system ignition coil connector
and ECM connector.
3. Check for the presence of spark from all of the
ignition wires.
Is the spark present from all of the ignition wires?–Go to Step 2Go to Step 22
22Replace ECM.
Is the repair complete?–Go to Step 2–
231. Turn the ignition OFF.
2. Connect a fuel pressure gauge.
3. Crank the engine.
Is any fuel pressure present?–Go to Step 26Go to Step 24
241. Turn the ignition OFF.
2. Disconnect the electrical connector at the fuel
pump.
3. Connect a test light between the fuel pump ter-
minals 2 and 3.
4. Turn the ignition ON.
5. With the ignition ON, the test light should light
for the time specified.
Is the test light on?2 sec.Go to Step 25Go to 34
25Replace the fuel pump.
Is the repair complete?–Go to Step 2–
26Is the fuel pressure within the value specified?283–324 kPa
(41–47 psi)Go to Step 27Go to Step 29
27Check the fuel for contamination.
Is the fuel contaminated?–Go to Step 28Go to Step 41
281. Remove the contaminated fuel from the fuel
tank.
2. Clean the fuel tank as needed.
Is the repair complete?–Go to Step 2–
291. Check the fuel filter for restriction.
2. Inspect the fuel lines for kinks and restrictions.
3. Repair or replace as needed.
4. Measure the fuel pressure.
Is the fuel pressure within the value specified?283–324 kPa
(41–47 psi)Go to Step 2Go to Step 30
ENGINE CONTROLS 1F – 43
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
301. Disconnect vacuum line from the fuel pressure
regulator.
2. Inspect the vacuum line for the presence of
fuel.
3. Inspect the fuel pressure regulator vacuum port
for the presence of fuel.
Is any fuel present?–Go to Step 31Go to Step 32
31Replace the fuel pressure regulator.
Is the repair complete?–Go to Step 2–
321. Remove the fuel pump assembly from the fuel
tank.
2. Inspect the fuel pump sender and the fuel cou-
pling hoses for a restriction.
3. Inspect the in–tank fuel filter for restriction.
Is the problem found?–Go to Step 33Go to Step 25
33Replace the fuel pump sender, the in–tank fuel filter,
and/or the fuel coupling hoses as needed.
Is the repair complete?–Go to Step 2–
341. Turn the ignition OFF.
2. Disconnect the electric connector at the fuel
pump.
3. Connect a test light between fuel pump con-
nector terminal 3 and ground.
4. Turn the ignition ON.
5. With the ignition ON, the test light should illumi-
nate for the time specified.
Is the test light on?2 secGo to Step 35Go to Step 36
35Repair the open circuit between the fuel pump con-
nector terminal 2 and ground.
Is the repair complete?–Go to Step 2–
361. Turn the ignition OFF.
2. Disconnect the fuel pump relay.
3. Turn the ignition ON.
4. Measure the voltage at terminal 30 and 86 of
fuel pump relay.
Is the voltage within the value specified?11–14 VGo to Step 38Go to Step 37
37Repair open or short circuit for power supply.
Is the repair complete?–Go to Step 2–
381. Turn the ignition OFF.
2. Disconnect ECM connector.
3. Using an ohmmeter, measure the resistance
between following terminals.
S Terminal 6 of ECM and terminal 85 of fuel
pump relay.
S Terminal 87 of fuel pump relay and terminal
3 of fuel pump.
Does the resistance within the value specified?0 WGo to Step 40Go to Step 39