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ENGINE CONTROLS 1F–31
DAEWOO M-150 BL2
No Malfunction Indicator Lamp
StepActionValue(s)YesNo
1
Attempt to start the engine.
Does the engine start?
–
Go to Step 2
Go to “Engine
Cranks But
Will Not Run”
2
1. Turn the ignition OFF.
2. Disconnect the engine control module (ECM)
connector.
3. Turn the ignition ON.
4. Connect a test light between terminal 68 of ECM
connector and ground.
Is the test light on?
–
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
4
Replace ECM
Is the repair complete?
–
Go to “On
Board
Diagnostic
System Check”
–
5
Repair any damaged terminals or poor connection.
Is the repair complete?
–
Go to “On
Board
Diagnostic
System Check”
–
6Check the fuse F1.
Is the fuse blown?–Go to Step 7Go to Step 8
7
1. Check for a short to ground in the circuit and
repair as needed.
2. Replace the blown fuse.
Is the repair complete?
–
Go to “On
Board
Diagnostic
System Check”
–
8
1. Check for an open circuit between fuse F16 and
terminal 68 of ECM connector and repair as
needed.
2. Check the MIL bulb and replace if blown.
Is the repair complete?
–
Go to “On
Board
Diagnostic
System Check”
–
Page 130 of 1184
1F–32 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F030
MALFUNCTION INDICATOR LAMP ON STEADY
Circuit Description
When the ignition is turned ON, the Malfunction Indica-
tor Lamp (MIL) will be turned ON and remain ON until
the engine is running, if no Diagnostic Trouble Codes
(DTCs) are stored. Battery voltage is supplied throughthe ignition switch directly to the MIL telltale. The Engine
Control Module (ECM) controls the MIL by providing a
ground path through the MIL control circuit to turn ON
the MIL.
Page 131 of 1184

ENGINE CONTROLS 1F–33
DAEWOO M-150 BL2
Malfunction Indicator Lamp On Steady
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the check complete.
–
Go to Step 2
Go to “Euro
On-Board
Diagnostic
System Check”
2
1. Turn the ignition OFF.
2. Install the scan tool.
3. Command the Malfunction Indicator Lamp (MIL)
on and off.
Does the MIL turn on and off when commanded?
–
Go to Step 7Go to Step 3
3
1. Turn the ignition OFF.
2. Disconnect the engine control module (ECM)
connector.
3. Turn the ignition ON.
Is the MIL off?
–
Go to Step 6Go to Step 4
4
Check the MIL control circuit for a short to ground
and repair as needed.
Is a repair necessary?
–
Go to Step 7Go to Step 5
5
Replace the instrument panel cluster. Refer to
Section 9E, Instrumentation/Driver Information.
Is the repair complete?
–
Go to Step 7
–
6Replace the ECM.
Is the repair complete?–Go to Step 7–
7
1. Using the scan tool, clear the Diagnostic Trouble
Codes(DTCs).
2. Attempt to start the engine.
Does the engine start and continue to run?
–
Go to Step 8Go to Step 1
8
Allow the engine to idle until normal operating
temperature is reached.
Check if any DTCs are set.
Are any DTCs displayed that have not been
diagnosed?
–
Go to applicable
DTC table
System OK
Page 132 of 1184

1F–34 ENGINE CONTROLS
DAEWOO M-150 BL2
FUEL SYSTEM DIAGNOSIS
Circuit Description
The fuel pump is an in-tank type mounted to a fuel send-
er assembly. The fuel pump will remain on as long as the
engine is cranking or running and the Engine Control
Module (ECM) is receiving reference pulses from the
crankshaft position (CKP) sensor. If there are no refer-
ence pulses, the ECM will turn off the fuel pump two sec-
onds after the ignition switch is turned ON or two
seconds after the engine stops running. The fuel pump
delivers fuel to the fuel rail and the fuel injectors, where
the fuel system pressure is controlled from 380 kPa (55
psi) by the fuel pressure regulator. The excess fuel is re-
turned to the fuel tank.
Caution: The fuel system is under pressure. To
avoid fuel spillage and the risk of personal injury orfire, it is necessary to relieve the fuel system pres-
sure before disconnecting the fuel lines.
Caution: Do not pinch or restrict nylon fuel lines.
Damage to the lines could cause a fuel leak, result-
ing in possible fire or personal injury.
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump fuse EF23 from the engine
fuse block.
3. Start the engine and allow the engine to stall.
4. Crank the engine for an additional 10 seconds.
Fuel System Pressure Test
Step Action Value(s) Yes No
1
1. Relieve the fuel system pressure.
2. Install a fuel pressure gauge.
3. Turn the ignition ON.
Is the fuel pressure around the values specified and
holding steady?
380 kPa
(55 psi)
System OK
Go to Step 2
2
1. Relieve the fuel system pressure.
2. Install a fuel pressure gauge.
3. Turn the ignition ON.
Is the fuel pressure around the values specified but
not holding steady?
380 kPa
(55 psi)
Go to Step 13
Go to Step 3
3
Inspect the fuel lines for a leak.
Is the problem found?
–
Go to Step 4
Go to Step 5
4
1. Replace the fuel line(s) as needed.
2. Install a fuel pressure gauge.
3. Turn the ignition ON.
Is the fuel pressure around the values specified and
holding steady?
380 kPa
(55 psi)
System OK
–
5
1. Remove the fuel pump assembly.
2. With the fuel pump under pressure, inspect the
fuel pump coupling hoses for leaking.
Is the problem found?
–
Go to Step 6
Go to Step 7
6
1. Tighten or replace the fuel pump coupling hoses
as needed.
2. Install a fuel pressure gauge.
3. Turn the ignition ON.
Is the fuel pressure around the values specified and
holding steady?
380 kPa
(55 psi)
System OK
Go to Step 8
7
With the fuel system under pressure, inspect the fuel
return outlet for leaking.
Is the problem found?
–
Go to Step 8
Go to Step 9
Page 133 of 1184