2004 DAEWOO LACETTI fuse

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”–

1F – 62IENGINE CONTROLS
DAEWOO V–121 BL4
FUEL SYSTEM DIAGNOSIS
Circuit Description
The fuel pump is an in–tank type mounted to a fuel sender
assembly. The fuel pump will remain on as long as the en-
gine is cranking or running and the Engine Control Module
(ECM) is receiving reference pulses from the crankshaft
position (CKP) sensor. If there are no reference pulses,
the ECM will turn off the fuel pump two seconds after the
ignition switch is turned ON or two seconds after the en-
gine stops running. The fuel pump delivers fuel to the fuel
rail and the fuel injectors, where the fuel system pressure
is controlled from 284 to 325 kPa (41 to 47 psi) by the fuel
pressure regulator. The excess fuel is returned to the fuel
tank.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
2. When the engine is idling, the intake manifold vacu-
um is high. This vacuum is applied to the fuel pres-
sure regulator diaphragm, offsetting the spring
pressure inside the fuel pressure regulator and low-
ering the fuel pressure.10. If there is fuel bleeding back through the fuel return
outlet, this is due to a faulty fuel pressure regulator.
14. Another symptom often present when the fuel injec-
tors are leaking is hard starting. Leaking fuel injec-
tors can cause a flooding condition.
23. Fuel leaking from the fuel pump inlet is due to a
faulty one–way check valve in the fuel pump.
CAUTION : The fuel system is under pressure. To
avoid fuel spillage and the risk of personal injury or
fire, it is necessary to relieve the fuel system pressure
before disconnecting the fuel lines.
CAUTION : Do not pinch or restrict nylon fuel lines to
avoid damage that could cause a fuel leak, resulting
in possible fire or personal injury.
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump fuse EF18 from the engine
fuse box.
3. Start the engine and allow the engine to stall.
4. Crank the engine for an additional 10 seconds.
Fuel System Diagnosis
StepActionValue(s)YesNo
11. Relieve the fuel system pressure.
2. Install a fuel pressure gauge.
3. Turn the ignition ON.
Is the fuel pressure within the values specified and
holding steady?284~325 kPa
(41~47psi)Go to Step 2Go to Step 4
21. Allow the engine to idle.
2. Disconnect the vacuum hose from the fuel
pressure regulator.
3. Connect a vacuum pump with a gauge to the
fuel pressure regulator vacuum port.
4. Apply 41~47 kPa (12~14 in. Hg) of vacuum to
the fuel pressure regulator.
Does the fuel pressure decrease?–Go to Step 3Go to Step 15
31. Locate and correct the cause of the vacuum
restriction to the fuel pressure regulator.
2. Confirm the operation of the fuel pressure reg-
ulator.
Is the repair complete?–System OK–
41. Relieve the fuel system pressure.
2. Install a fuel pressure gauge.
3. Turn the ignition ON.
Is the fuel pressure within the values specified but
not holding steady?284~325 kPa
(41~47psi)Go to Step 5Go to Step 16
5Inspect the fuel lines for a leak.
Is the problem found?–Go to Step 6Go to Step 7

ENGINE CONTROLS 1F – 67
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Replace the fuse F2 or repair the wire between
the fuel pump relay connector terminal 30 and
the battery.
2. Install the fuel pump relay.
3. Turn the ignition OFF for 10 seconds.
4. Turn the ignition ON.
Does the fuel pump operate for the time specified?2 secSystem OK–
121. Turn the ignition OFF.
2. Replace the ECM.
3. Turn the ignition ON.
Does the fuel pump operate for the time specified?2 secSystem OK–
131. Replace the fuse F2 or repair the wire between
the fuel pump relay connector terminal 30 and
the ignition system
2. Install the fuel pump relay.
3. Turn the ignition OFF for 10 seconds.
4. Turn the ignition ON.
Does the fuel pump operate for the time specified?2 secSystem OK–

1F – 70IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Replace the fuse Ef18 or repair the wire be-
tween the fuel pump relay connector terminal
30 and the battery.
2. Install the fuel pump relay.
3. Turn the ignition OFF for 10 seconds.
4. Turn the ignition ON.
Does the fuel pump operate for the time specified?2 secSystem OK–
121. Turn the ignition OFF.
2. Replace the ECM.
3. Turn the ignition ON.
Does the fuel pump operate for the time specified?2 secSystem OK–
131. Replace the fuse Ef18 or repair the wire be-
tween the fuel pump relay connector terminal
30 and the ignition system
2. Install the fuel pump relay.
3. Turn the ignition OFF for 10 seconds.
4. Turn the ignition ON.
Does the fuel pump operate for the time specified?2 secSystem OK–