1F – 50IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
35While cranking the engine, measure the voltage at
the EI system ignition coil connector terminal 3 .
Does the voltage fluctuate within the values speci-
fied?0.2–2.0 vGo to Step 39Go to Step 37
36Check for an open in the wire from the EI system
ignition coil connector terminal 1 to the ECM connec-
tor terminal M51.
Is the problem found?–Go to Step 38Go to Step 40
37Check for an open in the wire from the EI system
ignition coil connector terminal 3 to the ECM connec-
tor terminal M1.
Is the problem found?–Go to Step 38Go to Step 40
381. Repair the wiring as needed.
2. Connect the EI system ignition coil connector.
3. Check for the presence of spark from all of the
ignition wires.
Is spark present from all of the ignition wires?–Go to Step 3Go to Step 39
39Replace the EI system ignition coil.
Is the repair complete?–Go to Step 3–
401. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?–Go to Step 3–
411. Turn the ignition OFF.
2. Connect a fuel pressure gauge.
3. Crank the engine.
Is any fuel pressure present?–Go to Step 44Go to Step 42
421. Turn the ignition OFF.
2. Disconnect the electrical connector at the fuel
pump.
3. Connect a test light between the fuel pump
connector terminals 3 and 2.
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 secGo to Step 43Go to Step 53
43Replace the fuel pump.
Is the repair complete?–Go to Step 3–
44Is the fuel pressure within the value specified?283–324 kPa
(41–47 psi)Go to Step 48Go to Step 45
451. Check the fuel filter for a restriction.
2. Inspect the fuel lines for kinks and restrictions.
Is the problem found?–Go to Step 46Go to Step 47
461. Disconnect the vacuum line from the fuel pres-
sure 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?283–324 kPa
(41–47 psi)Go to Step 3Go to Step 47
ENGINE CONTROLS 1F – 51
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
471. Disconnect the vacuum line from the fuel pres-
sure 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 presen–Go to Step 50Go to Step 51
48Check the fuel for contamination.
Is the fuel contaminated?–Go to Step 49Go to Step 65
491. Remove the contaminated fuel from the fuel
tank.
2. Clean the fuel tank as needed.
Is the repair complete?–Go to Step 3–
50Replace the fuel pressure regulator.
Is the repair complete?–Go to Step 3–
511. 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 a restriction.
Is the problem found?–Go to Step 52Go to Step 43
52Replace the fuel pump sender, the in–tank fuel filter,
and/or the fuel coupling hoses as needed.
Is the repair complete?–Go to Step 3–
531. Turn the ignition OFF.
2. Disconnect the electrical connector at the fuel
pump.
3. Connect a test light between the fuel pump
connector terminal 3 and a known good
ground.
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 secGo to Step 54Go to Step 55
54Repair the open wire between the fuel pump connec-
tor terminal 2 and ground.
Is the repair complete–Go to Step 3–
551. Turn the ignition OFF.
2. Disconnect the fuel pump relay.
3. Connect a test light between the fuel pump
relay connector terminal 85 and ground.
4. Turn the ignition ON.
Is the test light on?2 secGo to Step 56Go to Step 62
561. Turn the ignition OFF.
2. Connect a test light between the fuel pump
relay connector terminal 86 and battery posi-
tive.
3. Turn the ignition ON.
4. With the ignition ON, the test light should light
for the time specified.
Is the test light on?–Go to Step 57Go to Step 61
1F – 52IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
571. Turn the ignition OFF.
2. Connect a test light between the fuel pump
relay connector terminal 30 and ground.
Is the test light on?–Go to Step 58Go toStep 63
581. Turn the ignition OFF.
2. Check the wire between the fuel pump relay
connector terminal 87 and the fuel pump con-
nector terminal 3 for an open or short to
ground.
Is the repair complete?–Go to Step 2–
59Replace the fuel pump relay.
Is the repair complete?–Go to Step 3–
601. Check for an open in the wiring between the
fuel pump relay connector terminal 86 and
ground.
Is the problem found?–Go to Step 71–
61Check the wire between the fuel pump relay connec-
tor terminal 85 to the ECM connector terminal K54
for an open.
Is the problem found?–Go to Step 62Go to Step 40
62Repair the wire between the fuel pump relay connec-
tor terminal 85 to the ECM connector terminal K54.
Is the repair complete?–Go to Step 3–
63Repair the wire between the fuel pump relay connec-
tor terminal 30 and the fuse Ef18.
Is the repair complete?–Go to Step 3–
641. Turn the ignition OFF.
2. Disconnect the fuel injector harness connectors
from all of the fuel injectors.
3. Turn the ignition ON.
4. Connect a test light between the fuel injector
harness connector 2 and ground.
5. Repeat step 4 for each of the remaining fuel
injectors.
Is the test light on at all of the fuel injectors?–Go to Step 65Go to Step 68
651. Turn the ignition OFF.
2. Connect a test light between the fuel injector
harness connector terminal 1 and battery posi-
tive.
3. Crank the engine.
4. Repeat steps two and three for each of the re-
maining fuel injectors.
Does the test light flash for all of the fuel injectors?–Go to Step 66Go to Step 69
66Measure the resistance of each fuel injector.
Is the resistance within the value specified (the re-
sistance will increase slightly at higher tempera-
tures)?11.6–12.4 WSystem OKGo to Step 67
67Replace any of the fuel injectors with a resistance
out of specification.
Is the repair complete?–Go to Step 3–
ENGINE CONTROLS 1F – 53
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
68Repair the open wire(s) between the fuel injector
harness connector(s) terminal 2 and the engine har-
ness C103 terminal 10.
Is the repair complete?–Go to Step 3–
691. Check for an open between the #1 fuel injector
harness connector terminal 1 and the connec-
tor terminal M25.
2. Check for an open between the #2 fuel injector
harness connector terminal 1 and the connec-
tor terminal M22.
3. Check for an open between the #3 fuel injector
harness connector terminal 1 and the connec-
tor terminal M24.
4. Check for an open between the #4 fuel injector
harness connector terminal 1 and the connec-
tor terminal M11.
Is the problem found?–Go to Step 70Go to Step 72
70Repair the open fuel injector harness wire(s).
Is the repair complete?–Go to Step 3–
71Replace the fuse or repair the wiring as needed.
Is the repair complete?–Go to Step 3–
721. Inspect the I/P fuse F2.
2. Check for an open between the circuits from
terminal 2 for each of the four fuel injectors and
the ignition switch.
Is the problem found?–Go to Step 71–
1F – 54IENGINE CONTROLS
DAEWOO V–121 BL4
NO MALFUNCTION INDICATOR LAMP (1.4L/1.6L DOHC)
Circuit Description
When the ignition is turned ON, the Malfunction Indicator
Lamp (MIL) will be turned ON and remain ON until the en-
gine is running, if no Diagnostic Trouble Codes (DTCs) are
stored. Battery voltage is supplied through the ignition
switch directly to the MIL telltale. The Engine Control Mod-
ule (ECM) controls the MIL by providing a ground path
through the MIL control circuit to turn ON the MIL.
Diagnostic Aids
An open ignition fuse F4 will cause the entire cluster to beinoperative.
Check the battery and ignition feed circuits for poor con-
nections if the MIL is intermittent.
Any circuitry, that is suspected as causing an intermittent
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.
ENGINE CONTROLS 1F – 55
DAEWOO V–121 BL4
No Malfunction Indicator Lamp (1.4L/1.6L DOHC)
StepActionValue(s)YesNo
1Attempt to start the engine.
Does the engine start?–Go to Step 2Go to
”Engine Cranks
But Will Not
Run”
21. Turn the ignition switch to LOCK.
2. Disconnect the Engine Control Module (ECM)
connector.
3. Turn the ignition switch to ON.
4. Connect a test light between the ECM connec-
tor terminal 39 and ground.
Is the test light illuminate?–Go to Step 3Go to Step 6
3Check terminals for damage or poor connection.
Does any problem found?–Go to Step 5Go to Step 4
4Replace the ECM.
Is the replacement complete?–Go to
”On–Board
Diagnostic Sys-
tem Check”–
5Repair any damaged terminals or poor connection.
Is the repair complete?–Go to
”On–Board
Diagnostic Sys-
tem Check”–
6Check the fuse F4.
Is the fuse open?Go to Step 7Go to Step 8
71. Check for a short to ground in the circuit and
repair as needed.
2. Replace the fuse F4.
Is the repair or replacement complete?–Go to
”On–Board
Diagnostic Sys-
tem Check”–
81. Check for an open circuit between fuse F4 and
the ECM connector terminal 39 and repair as
needed.
2. Check the MIL bulb and replace if open.
Is the repair or replacement complete?–Go to
”On–Board
Diagnostic Sys-
tem Check”–
1F – 56IENGINE CONTROLS
DAEWOO V–121 BL4
NO MALFUNCTION INDICATOR LAMP (1.8L DOHC)
Circuit Description
When the ignition is turned ON, the Malfunction Indicator
Lamp (MIL) will be turned ON and remain ON until the en-
gine is running, if no Diagnostic Trouble Codes (DTCs) are
stored. Battery voltage is supplied through the ignition
switch directly to the MIL telltale. The Engine Control Mod-
ule (ECM) controls the MIL by providing a ground path
through the MIL control circuit to turn ON the MIL.
Diagnostic Aids
An open ignition fuse F4 will cause the entire cluster to be
inoperative.
Check the battery and ignition feed circuits for poor con-
nections if the MIL is intermittent.Any circuitry, that is suspected as causing an intermittent
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.
Test Description
Number(s) below refer to the step(s) on the diagnostic
table.
1. If the engine fails to start and the MIL is inopera-
tive, then the fault can be isolated to either the
ECM ignition feed. The battery feed, or a poor
ground at the engine block, or the ECM.
2. Probing the MIL circuit with a test light to ground
stimulates the ECM’s control of the MIL. If the MIL
illuminates, then the malfunction can be isolated to
the control of the MIL or a poor connection at the
MIL terminal to the ECM.
ENGINE CONTROLS 1F – 57
DAEWOO V–121 BL4
No Malfunction Indicator Lamp (1.8L DOHC)
StepActionValue(s)YesNo
1Attempt to start the engine.
Does the engine start?–Go to Step 2Go to
”Engine Cranks
But Will Not
Run”
21. Turn the ignition switch to LOCK.
2. Disconnect the Engine Control Module (ECM)
connector.
3. Turn the ignition switch to ON.
4. Connect a test light between the ECM connec-
tor terminal K64 and ground.
Is the test light illuminate?–Go to Step 3Go to Step 6
3Check terminals for damage or poor connection.
Does any problem found?–Go to Step 5Go to Step 4
4Replace the ECM.
Is the replacement complete?–Go to
”On Board
Diagnostic Sys-
tem Check”–
5Repair any damaged terminals or poor connection.
Is the repair complete?–Go to
”On Board
Diagnostic Sys-
tem Check”–
6Check the fuse F4.
Is the fuse open?Go to Step 7Go to Step 8
71. Check for a short to ground in the circuit and
repair as needed.
2. Replace the fuse F4.
Is the repair or replacement complete?–Go to
”On Board
Diagnostic Sys-
tem Check”
81. Check for an open circuit between fuse F4 and
the ECM connector terminal K64 and repair as
needed.
2. Check the MIL bulb and replace if open.
Is the repair or replacement complete?–Go to
”On Board
Diagnostic Sys-
tem Check”–