Page 145 of 1184

ENGINE CONTROLS 1F–47
DAEWOO M-150 BL2
Ignition System Check (Cont’d)
StepActionValue(s)YesNo
21
Measure the voltage between the CKP sensor
connector terminal 2 and ground.
Is the voltage within the value specified?
0.95–1.10 VGo to Step 18Go to Step 22
22
Check the wire between the CKP sensor connector
terminal 2 and the ECM connector terminal 24 for an
open or short.
Is the problem found?
–
Go to Step 23Go to Step 11
23
Repair the wire between the CKP sensor connector
terminal 2 and the ECM connector terminal 24.
Is the repair complete?
–
System OK
–
24
1. Turn the ignition OFF.
2. Connect a test light between the EI system
ignition coil connector terminal 2 and ground.
3. Turn the ignition ON.
Is the test light on?
–
Go to Step 27Go to Step 25
25
Check for an open in the wiring between the EI
system ignition coil connector, terminal 1 and the
main relay connector terminal 87.
Is the problem found?
–
Go to Step 26
Go to “Main
Relay Circuit
Check”
26
Repair the open in the wiring between the EI system
ignition coil connector terminal 1 and the main relay
connector terminal 87.
Is the repair complete?
–
System OK
–
27
Check for a damage in the terminal of the EI system
ignition coil connector and repair as needed.
Is the repair complete?
–
System OK
–
Page 146 of 1184

1F–48 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F090
ENGINE COOLING FAN CIRCUIT CHECK
Circuit Description
The engine cooling fan circuit operates the cooling fan.
The cooling fan is controlled by the engine control mod-
ule (ECM) based on input from the coolant temperature
sensor (CTS) and the A/C ON/OFF. The ECM controls
the low speed cooling fan operation by internally ground-
ing the ECM connector terminal 39. This energizes the
low speed cooling fan relay and operates the cooling fan
at low speed. The low speed cooling fan operation is
achieved by the cooling fan resistor causing a drop in
the voltage supplied to the cooling fan. The ECM con-
trols the high speed cooling fan operation by internally
grounding the ECM connector terminal 5. This ener-
gizes the high speed cooling fan relay, bypassing the ra-
diator fan resistor. This results in high speed cooling fan
operation.
Diagnostic Aids
If the owner complained of an overheating problem, it
must be determined if the complaint was due to anactual boil over, or the engine coolant temperature
gauge indicated overheating. If the engine is over-
heating and the cooling fans are on, the cooling sys-
tem should be checked.
If the engine fuse block fuse EF15 become open
(blown) immediately after installation, inspect for a
short to ground in the wiring of the appropriate circuit.
If the fuse become open (blown) when the cooling
fans are to be turned on by the Engine Control Mod-
ule (ECM), suspect a faulty cooling fan motor.
The ECM will turn the cooling fan on at low speed
when the coolant temperature is 93C (199F). The
ECM will turn the cooling fans off when the coolant
temperature is 90C (194F).
The ECM will turn the cooling fans on at high speed
when the coolant temperature is 100C (212F). The
ECM will change the cooling fans from high speed to
low speed when the coolant temperature is 97C
(207F).
Page 147 of 1184

ENGINE CONTROLS 1F–49
DAEWOO M-150 BL2
Engine Cooling Fan Circuit Check
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Was the check performed?
–
Go to Step 2
Go to “Euro
On-Board
Diagnostic
System Check.
2
1. Check the fuses EF3 and EF10 in engine fuse
block.
2. Replace the fuse(s) as needed.
Is the fuse(s) OK?
–
Go to Step 3
Go to
“Diagnostic
Aids”
3
1. Turn the ignition OFF.
2. Turn the A/C switch OFF. If equipped.
3. Connect a scan tool to the Data Link Connector
(DLC).
4. Start the engine.
5. The main cooling fan should run at low speed
when the coolant temperature reaches 96C
(205F).
Does the cooling fan run at low speed?
–
Go to Step 4Go to Step 8
4
The cooling fans should run at high speed when the
coolant temperature reaches 100C (212F).
Do the cooling fans run at high speed?
–
Go to Step 5Go to Step 19
5
1. Turn the ignition OFF.
2. Start the engine.
3. Turn the A/C switch ON.
Does the cooling fan runs at low speed?
–
Go to Step 7Go to Step 6
6
1. Diagnose the A/C compressor clutch circuit.
2. Repair the A/C compressor clutch circuit as
needed.
Is the repair complete?
–
System OK
–
7
1. Turn the ignition OFF.
2. Start the engine.
3. Turn the A/C switch ON and raise the rpm.
4. The cooling fan should run at high speed when
the high side A/C pressure reaches 2068 kPa
(300 psi).
Do the cooling fans run at high speed?
–
System OK
–
8
1. Turn the ignition OFF.
2. Disconnect the cooling fan connector.
3. Turn the ignition ON.
4. Connect a test light between terminal 1 of cooling
fan connector and ground.
Is the test light on?
–
Go to Step 9Go to Step 12
9
Connect a test light between terminal 2 of cooling
fan connector and battery positive.
Is the test light on?
–
Go to Step 11Go to Step 10
10
Repair open circuit between terminal 2 of cooling fan
connector and ground.
Is the repair complete?
–
System OK
–
11
Check for a damaged terminals in main cooling fan
connector and repair it or replace the main cooling
fan.
Is the repair complete?
–
System OK
–
Page 148 of 1184

1F–50 ENGINE CONTROLS
DAEWOO M-150 BL2
Engine Cooling Fan Circuit Check (Cont’d)
StepActionValue(s)YesNo
12
1. Turn the ignition ON.
2. Connect a test light between terminals 86 and 30
of low speed cooling fan relay and ground.
Does the test light on for both case?
–
Go to Step 14Go to Step 13
13
Repair power supply circuit.
Fuse EF15 and terminal 30 of low speed cooling
fan relay.
Is the repair complete?
–
System OKGo to Step 14
14
1. Turn the ignition OFF.
2. Disconnect Engine Control Module (ECM)
connectors.
3. Turn the ignition ON.
4. Connect a jump wire between terminal 5 and
ground.
Does the cooling fan run at low speed?
–
Go to Step 15Go to Step 16
15Replace the ECM.
Is the repair complete?–System OK–
16
1. Turn the ignition OFF.
2. Measure the resistance between following
terminals:
Terminal 85 of low speed cooling fan relay and
terminal 39 of ECM connector.
Are the resistance within the value specified?
0 ΩGo to Step 18Go to Step 17
17Repair open circuit.
Is the repair complete?–System OK–
18Replace the low speed cooling fan relay.
Is the repair complete?–System OK–
Page 149 of 1184
ENGINE CONTROLS 1F–51
DAEWOO M-150 BL2
BLANK
Page 150 of 1184

1F–52 ENGINE CONTROLS
DAEWOO M-150 BL2
MAA1F010
DATA LINK CONNECTOR DIAGNOSIS
Circuit Description
The provision for communicating with the Engine Con-
trol Module (ECM) is the Data Link Connector (DLC). It
is located under the instrument panel. The DLC is used
to connect the scan tool. Battery power and ground is
supplied for the scan tool through the DLC. The Key-
word 2000 serial data circuit to the DLC allows the ECM
to communicate with the scan tool. A Universal Asyn-
chronous Receiver Transmitter (UART) serial data line
is used to communicate with the other modules such as
the Electronic Brake Control Module (EBCM), the Sup-
plemental Inflatable Restraint (SIR) system. and the In-
strument Panel Cluster.
Diagnostic Aids
Ensure that the correct application (model line, car year,
etc.) has been selected on the scan tool. If communica-
tion still cannot be established, try the scan tool onanother vehicle to ensure that the scan tool or cables
are not the cause of the condition.
An intermittent may be caused by a poor connection,
rubbed through wire insulation, or a broken wire inside
the insulation.
Any circuitry that is suspected of causing an intermittent
complaint should be thoroughly checked for the follow-
ing conditions:
Backed-out terminals.
Improper mating of terminals.
Broken locks.
Improperly formed or damaged terminals.
Poor terminal-to-wiring connection.
Physical damage to the wiring harness.
Corrosion.
Page 151 of 1184

ENGINE CONTROLS 1F–53
DAEWOO M-150 BL2
Data Link Connector Diagnosis
StepActionValue(s)YesNo
1
Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Was the check performed?
–
Go to Step 2
Go to “Euro
On-Board
Diagnostic
System Check.
2
With a test light connected to the ground, probe the
Data Link Connector (DLC) battery feed terminal 16.
Is the test light on?
–
Go to Step 4Go to Step 3
3
Repair an open or short to ground in the DLC battery
feed circuit .
Is the repair complete?
–
Go to Step 4
–
4
With a test light connected to the battery, probe the
Data Link Connector (DLC) ground terminal 4 and 5.
Is the test light on?
–
Go to Step 6Go to Step 5
5Repair an open circuit .
Is the repair complete?–Go to Step 6–
6
1. Turn the ignition OFF.
2. Connect a scan tool to the Data Link Connector
(DLC).
3. Turn the ignition ON.
Does the scan tool power up?
–
Go to Step 8Go to Step 7
7
Check for damages in the terminal of DLC and scan
tool, and repair as needed.
Is the repair complete?
–
Go to Step 8
–
8
Using a scan tool, request engine data of Engine
Control Module (ECM).
Does the scan tool display any data?
–
Go to Step 12Go to Step 9
9
Install the scan tool on another vehicle and check for
proper operation.
Does the scan tool work properly on a different
vehicle.
–
Go to Step 11Go to Step 10
10
The scan tool is malfunctioning.
Refer to the scan tool’s manual for repair.
Is the repair complete?
–
Go to Step 12
–
11
Repair communication circuit between ECM and
DLC.
Is the repair complete?
–
Go to Step 12
–
12
1. Using a scan tool, clear the Diagnostic Trouble
Codes(DTCs).
2. Attempt to start the engine.
Does the engine and continue to run?
–
Go to Step 13Go to Step 1
13
1. Allow the engine to idle until normal operation
temperature reached.
2. Check if any DTCs are set?
Are any DTCs displayed that have not been
diagnosed?
–
Go to applicable
DTC table
System OK
Page 152 of 1184

1F–54 ENGINE CONTROLS
DAEWOO M-150 BL2
FUEL INJECTOR BALANCE TEST
A fuel injector tester is used to energize the injector for a
precise amount of time, thus spraying a measured
amount of fuel into the intake manifold. This causes adrop in the fuel rail pressure that can be recorded and
used to compare each of the fuel injectors. All of the fuel
injectors should have the same pressure drop.
Fuel Injector Balance Test Example
Cylinder123
First Reading380 kPa
(55 psi)380 kPa
(55 psi)380 kPa
(55 psi)
Second Reading215 kPa
(31 psi)201 kPa
(29 psi)230 kPa
(33 psi)
Amount Of Drop165 kPa
(24 psi)179 kPa
(26 psi)151 kPa
(22 psi)
Average Range: 156-176 kPa
(22.5-25.5 psi)Injector OKFaulty Injector –
Too Much
Pressure DropFaulty Injector –
Too Little
Pressure Drop
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 pres-
sure before disconnecting the fuel lines.
Caution: Do not pinch or restrict fuel lines. Damage
to the lines could cause a fuel leak, resulting in pos-
sible fire or personal injury.
Notice: In order to prevent flooding of the engine, do not
perform the Injector Balance Test more than once (in-
cluding any retest on faulty fuel injectors) without run-
ning the engine.
Test
Notice: An engine cool down period of 10 minutes is
necessary in order to avoid irregular readings due to hot
soak fuel boiling.
1. Connect the fuel pressure gauge carefully to avoid
any fuel spillage.
2. The fuel pump should run about 2 seconds after the
ignition is turned to the ON position.
3. Insert a clear tube attached to the vent valve of the
fuel pressure gauge into a suitable container.
4. Bleed the air from the fuel pressure gauge and hose
until all of the air is bled from the fuel pressure gauge.
5. The ignition switch must be in the OFF position at
least 10 seconds in order to complete the electronic
control module (ECM) shutdown cycle.6. Turn the ignition ON in order to get the fuel pressure
to its maximum level.
7. Allow the fuel pressure to stabilize and then record
this initial pressure reading. Wait until there is no
movement of the needle on the fuel pressure gauge.
8. Follow the manufacturer’s instructions for the use of
the adapter harness. Energize the fuel injector test-
er once and note the fuel pressure drop at its lowest
point. Record this second reading. Subtract it from
the first reading to determine the amount of the fuel
pressure drop.
9. Disconnect the fuel injector tester from the fuel in-
jector.
10. After turning the ignition ON, in order to obtain maxi-
mum pressure once again, make a connection at
the next fuel injector. Energize the fuel injector test-
er and record the fuel pressure reading. Repeat this
procedure for all the injectors.
11. Retest any of the fuel injectors that the pressure
drop exceeds the 10 kPa (1.5 psi) specification.
12. Replace any of the fuel injectors that fail the retest.
13. If the pressure drop of all of the fuel injectors is with-
in 10 kPa (1.5 psi), then the fuel injectors are flowing
normally and no replacement should be necessary.
14. Reconnect the fuel injector harness and review the
symptom diagnostic tables.