2003 DAEWOO MATIZ Service Repair Manual

ENGINE CONTROLS 1F–295
DAEWOO M-150 BL2
Cuts Out, Misses (Cont’d)
StepActionValue(s)YesNo
12
1. Repair or replace the faulty injector drive circuit
harness, the connector, or the connector terminal.
2. If the connections and the harnesses are good,
replace the Engine Control Module (ECM).
Is the repair complete?
–
System OK
–
13
Measure the resistance of each fuel injector.
Is the injector resistance within the value specified
(the resistance will increase slightly at higher
temperatures)?
11.6–12.4 ΩGo to Step 15Go to Step 14
14
Replace any fuel injectors with a resistance that is
out of specifications.
Is the repair complete?
–
System OK
–
15Perform an injector diagnosis.
Is the problem found?–Go to Step 16Go to Step 17
16Replace any restricted or leaking fuel injectors.
Is the repair complete?–System OK–
17
1. Check for electromagnetic interference.
2. Monitor the engine rpm with a scan tool.
Does the scan tool rpm change greatly with little
change in actual engine rpm?
–
Go to Step 18
–
18
1. Inspect the routing of the ignition wires.
2. Inspect all of the ignition system grounds.
3. Correct the routing or repair the ground
connections as needed.
Are all checks and needed repairs complete?
–
System OK
–

1F–296 ENGINE CONTROLS
DAEWOO M-150 BL2
POOR FUEL ECONOMY
Definition: Fuel economy, as measured by an actual
road test, is noticeably lower than expected. Also, fuel
economy is noticeably lower than it was on this vehicle
at one time, as previously shown by an actual road test.
Important: Driving habits affect fuel economy. Check
the owner’s driving habits by asking the following ques-
tions:1. Is the A/C system (i.e. defroster mode) turned on all
the time?
2. Are the tires at the correct air pressure?
3. Have excessively heavy loads been carried?
4. Does the driver accelerate too much and too often?
Suggest the driver read the section in the owner’s
manual about fuel economy.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
1. Inspect the air filter for excessive contamination.
2. Inspect for fuel system leaks.
Are all needed checks complete?
–
Go to Step 3
–
3
1. Inspect the spark plugs for excessive wear,
insulation cracks, improper gap, or heavy
deposits.
2. Replace any faulty spark plugs.
3. Inspect the ignition wires for cracking, hardness,
and proper connections.
Are all needed checks and repairs complete?
–
Go to Step 4
–
4
1. Inspect the engine coolant level.
2. Check the thermostat for being always open or for
an incorrect heat range.
3. Replace the thermostat as needed.
Are all needed checks and repairs complete?
–
Go to Step 4
–
5
1. Check the transaxle shift pattern. Ensure all
transaxle gears are functioning.
2. Check for proper calibration of the speedometer.
3. Check the brakes for dragging.
4. Check the cylinder compression.
5. Repair, replace, or adjust any components as
needed.
Are all checks and needed repairs complete?
–
System OK
–

ENGINE CONTROLS 1F–297
DAEWOO M-150 BL2
ROUGH, UNSTABLE, OR INCORRECT IDLE, STALLING
Definition: The engine runs unevenly at idle. If the condi-
tion is bad enough, the vehicle may shake. Also, the idle
varies in rpm (called “hunting”). Either condition may be
severe enough to cause stalling. The engine idles at in-
correct idle speed.Important: Before diagnosing the symptom, check ser-
vice bulletins for updates.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
1. Connect the scan tool to the Data Link Connector
(DLC).
2. Monitor the oxygen sensor (O2S) reading at
different throttle positions.
Does the O2S change quickly from rich to lean at
the different throttle positions?
–
Go to Step 5Go to Step 3
3
Check the O2S for contamination from fuel or
improper use of room temperature vulcanizing
sealant.
Is the O2S contaminated?
–
Go to Step 4Go to Step 5
4Replace the contaminated O2S as needed.
Is the repair complete?–System OK–
5
1. Check for a sticking throttle shaft or binding
throttle linkage that may cause incorrect Throttle
Position (TP) sensor voltage.
2. Check the TP sensor voltage reading with the
throttle closed.
Is the TP sensor voltage within the value specified?
0.4–0.8 VGo to Step 6
Go to
“Diagnostic
Aids for DTC
P0123”
6
1. Check the Engine Coolant Temperature (ECT)
sensor voltage reading using the scan tool.
2. Compare the ECT sensor reading with the
ambient temperature when the engine is cold.
Does the ECT sensor temperature reading differ
from the ambient temperature by more than the
value specified?
3
C (5
F)Go to Step 7Go to Step 9
7
Check for high resistance in the ECT sensor circuit
or the sensor itself.
Is the problem found?
–
Go to Step 8Go to Step 9
8
Replace the ECT sensor or repair the circuit as
needed.
Is the repair complete?
–
System OK
–
9
Check the Manifold Absolute Pressure (MAP)
sensor for response and accuracy.
Is the problem found?
–
Go to Step 10Go to Step 11
10
Replace the MAP sensor or repair the MAP sensor
circuit as needed.
Is the repair complete?
–
System OK
–
11
1. Road test the vehicle at the speed of the
complaint.
2. Monitor the long term fuel trim reading using the
scan tool.
Is the long term fuel trim reading within the value
specified?
–20–25%Go to Step 14Go to Step 12

1F–298 ENGINE CONTROLS
DAEWOO M-150 BL2
Rough, Unstable, or Incorrect Idle, Stalling (Cont’d)
StepActionValue(s)YesNo
12
Is the long term fuel trim reading below the value
specified?
–20%
Go to
“Diagnostic Aids
for DTC P0172”
Go to Step 13
13
Is the long term fuel trim reading above the value
specified?
25%
Go to
“Diagnostic Aids
for DTC P0171”
–
14
1. Disconnect all of the fuel injector harness
connectors at the fuel injectors.
2. Connect an injector test light between the
harness terminals of each fuel injector connector.
3. Note the test light while cranking the engine.
Does the test light blink for all of the fuel injectors?
–
Go to Step 16Go to Step 15
15
1. Repair or replace the faulty injector drive circuit
harness, the connector, or the connector
terminals as needed.
2. If the harness, the connectors, and the terminals
are OK, replace the Engine Control Module
(ECM).
Is the repair complete?
–
System OK
–
16
Measure the resistance of each of the fuel injectors.
Is the resistance within the value specified (the
resistance will increase slightly at higher
temperatures)?
11.6–12.4 ΩGo to Step 18Go to Step 17
17
Replace any fuel injectors with a resistance that is
out of specifications.
Is the repair complete?
–
System OK
–
18Perform an injector diagnosis.
Is the problem found?–Go to Step 19Go to Step 20
19Replace any leaking or restricted fuel injectors.
Is the repair complete?–System OK–
20
1. With the engine OFF, disconnect the fuel
pressure regulator vacuum hose.
2. Thoroughly inspect the fuel pressure regulator
vacuum port and the fuel pressure regulator
vacuum hose for the presence of fuel.
Is the problem found?
–
Go to Step 21Go to Step 22
21Replace the fuel pressure regulator as needed.
Is the repair complete?–System OK–
22
1. Check the ignition system output voltage for all of
the cylinders using a spark tester.
2. Inspect the spark plugs for excessive wear,
insulation cracks, improper gap, or heavy
deposits.
3. Inspect the ignition wires for cracking, hardness,
or improper connections.
4. Replace any ignition wires with a resistance over
the value specified.
Is the problem found?
30000 ΩGo to Step 23Go to Step 24
23
Repair or replace any ignition system components
as needed.
Is the repair complete?
–
System OK
–

ENGINE CONTROLS 1F–299
DAEWOO M-150 BL2
Rough, Unstable, or Incorrect Idle, Stalling (Cont’d)
StepActionValue(s)YesNo
24
1. Inspect for vacuum leaks.
2. Check for proper Positive Crankcase Ventilation
(PCV) operation.
3. Check the Idle Air Control (IAC) valve operation.
4. Inspect the ECM ground connections.
Is the problem found?
–
Go to Step 25Go to Step 26
25Repair or replace any components as needed.
Is the repair complete?–System OK–
26
1. Check the Electric Exhaust Gas Recirculation
(EEGR) valve for proper operation.
2. Inspect the battery cables and the ground straps
for proper connections.
3. Check the generator voltage output. Repair or
replace the generator if the voltage output is not
within the value specified.
Is the problem found?
12–16 VGo to Step 27Go to Step 28
27Repair or replace any components as needed.
Is the repair complete?–System OK–
28
1. Inspect for broken engine mounts.
2. Check for proper valve timing.
3. Perform a cylinder compression test.
4. Inspect for bent pushrods, worn rocker arms,
broken or weak valve springs, and a worn
camshaft.
5. Perform repairs as needed.
Are all of the checks and needed repairs complete?
–
System OK
–

1F–300 ENGINE CONTROLS
DAEWOO M-150 BL2
EXCESSIVE EXHAUST EMISSIONS OR ODORS
Definition: A vehicle fails an emission test. The vehicle
has an excessive rotten egg smell. Excessive odors do
not necessarily indicate excessive emissions.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2
1. Run the engine until it reaches operating
temperature.
2. Perform an emission test.
Did the vehicle pass the emission test?
–
System OKGo to Step 3
3
1. Connect the scan tool to the Data Link Connector
(DLC).
2. Road test the vehicle.
3. Monitor the long term fuel trim memory.
Is the long term fuel trim memory within the value
specified?
–20 – 25 %Go to Step 6Go to Step 4
4
Is the long term fuel trim memory below the value
specified?
–20 %
Go to
“Diagnostic Aids
for DTC P0172”
Go to Step 5
5
Is the long term fuel trim memory above the value
specified?
25 %
Go to
“Diagnostic Aids
for DTC P0171”
–
6
1. Check for a properly installed fuel cap.
2. Check the fuel system pressure.
3. Perform an injector diagnosis.
Is the problem found?
–
Go to Step 7Go to Step 8
7
1. Repair or replace any fuel system components as
needed.
2. Perform an emission test.
Did the vehicle pass the emission test?
–
System OK
–
8
1. Check the ignition system for proper operation.
2. Inspect the spark plugs for excessive wear,
insulation cracks, improper gap, or heavy
deposits.
3. Check the ignition wires for cracking, hardness, or
improper connections.
Is the problem found?
–
Go to Step 9Go to Step 10
9
1. Repair or replace any ignition system components
as needed.
2. Perform an emission test.
Did the vehicle pass the emission test?
–
System OK
–

ENGINE CONTROLS 1F–301
DAEWOO M-150 BL2
Excessive Exhaust Emissions or Odors (Cont’d)
StepActionValue(s)YesNo
10
1. Inspect for vacuum leaks.
2. Inspect the catalytic converter for contamination.
3. Inspect for carbon buildup on the throttle body
and the throttle plate and inside the engine.
Remove with a top engine cleaner.
4. Check the Electric Exhaust Gas Recirculation
(EEGR) valve for not opening.
5. Check for proper Positive Crankcase Ventilation
(PCV) operation.
Are all checks and needed repairs complete?
–
System OK
–

1F–302 ENGINE CONTROLS
DAEWOO M-150 BL2
DIESELING, RUN-ON
Definition: An engine continues to run after the ignition
switch is turned OFF.
StepActionValue(s)YesNo
1
Were the Important Preliminary Checks performed?
–
Go to Step 2
Go to
“Important
Preliminary
Checks”
2Does the engine run smoothly after the ignition
switch is turned OFF?–Go to Step 3Go to Step 4
3
1. Check the ignition switch and the ignition switch
adjustment.
2. Replace the ignition switch if needed.
Is the repair complete?
–
System OK
–
4
1. Check the evaporative emission system.
2. Check for leaking fuel injectors.
3. Check the Idle Air Control (IAC) valve operation.
4. Inspect for vacuum leaks.
5. Check for the proper base idle setting.
Are all checks and repairs complete?
–
System OK
–