DAEWOO NUBIRA 2004 Service Repair Manual

ENGINE CONTROLS 1F – 95
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Turn the ignition OFF.
2. Connect a scan tool to the DLC.
3. The coolant temperature should be above
97°C (207°C).
4. Disconnect the main cooling fan connector.
5. Connect a test light between the main cooling
fan connector terminal 1 and ground.
Is the test light on?–Go to Step 28Go to Step 17
121. Turn the ignition OFF.
2. Disconnect the cooling fan relay Low.
3. Connect a test light between the cooling fan
relay Low connector terminal 85 and ground.
4. Turn the ignition ON.
Is the test light on?–Go to Step 13Go to Step 24
131. Turn the ignition OFF.
2. Connect the cooling fan relay Low.
3. Disconnect engine control module (ECM) white
connector.
4. Connect a fused jumper between the ECM
connector terminal 10 and ground.
5. Turn the ignition ON.
Do the cooling fans run at low speed?–Go to Step 30Go to Step 14
14Check for an open wire between the low speed cool-
ing fan relay connector terminal 85 and the ECM
connector terminal 10.
Is the problem found?–Go to Step 25Go to Step 15
151. Turn the ignition OFF.
2. Disconnect the cooling fan relay Low.
3. Connect a test light between the cooling fan
relay Low connector terminal 30 and ground.
Is the test light on?–Go to Step 16Go to Step 23
16Connect a fused jumper between the cooling fan
relay Low connector terminals 30 and 87.
Do the cooling fans run at low speed?–Go to Step 26Go to Step 17
171. Disconnect the cooling fan control relay.
2. Connect a fused jumper between the cooling
fan relay Low connector terminals 30 and 87.
3. Connect a fused jumper between the cooling
fan control relay connector terminals 30 and
87.
Do the cooling fans run at low speed?–Go to Step 27Go to Step 18
18Check the wire between the cooling fan relay Low
connector terminal 87 to the main cooling fan con-
nector terminal 2 for an open.
Is the problem found?–Go to Step 22Go to Step 19
19Check the wire between the main cooling fan con-
nector terminal 1 and the cooling fan control relay
connector terminal 30 for an open.
Is the problem found?–Go to Step 22Go to Step 20

1F – 96IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
20Check the wire between the cooling fan control relay
connector terminal 87A and the auxiliary cooling fan
connector terminal 2 for an open.
Is the problem found?–Go to Step 22Go to Step 21
21Check for an open wire between the auxiliary cooling
fan connector terminal 1 and ground.
Is the problem found?–Go to Step 22Go to Step 29
22Repair the open wire as needed.
Is the repair complete?–System OK–
23Repair the open between the cooling fan relay Low
connector terminal 30 and the fuse Ef11.
Is the repair complete?–System OK–
24Repair the open between the cooling fan relay Low
connector terminal 86 and the ignition switch.
Is the repair complete?–System OK–
25Repair the open wire between the cooling fan relay
Low connector terminal 85 and the ECM connector
terminal 10.
Is the repair complete?–System OK–
26Replace the cooling fan relay Low.
Is the repair complete?–System OK–
27Replace the cooling fan control relay.
Is the repair complete?–System OK–
28Replace the main cooling fan.
Is the repair complete?–System OK–
29Replace the auxiliary cooling fan.
Is the repair complete?–System OK–
30Replace the ECM.
Is the repair complete?–System OK–
311. Turn the ignition OFF.
2. Disconnect the main cooling fan connector.
3. Connect a test light between the main cooling
fan connector termina 2 and ground.
4. Turn the A/C switch ON.
5. Start the engine.
Is the test light on?–Go to Step 32Go to Step 12
321. Turn the ignition OFF.
2. Connect a test light between the main cooling
fan connector terminal 1 and battery positive.
3. Turn the A/C switch ON.
4. Start the engine.
Is the test light on?–Go to Step 28Go to Step 17
331. Turn the ignition OFF.
2. Disconnect the cooling fan relay Hi.
3. Connect a test light between the cooling fan
relay Hi connector terminal 86 and ground.
4. Turn the ignition ON.
Is the test light on?–Go to Step 34Go to Step 44

ENGINE CONTROLS 1F – 97
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
341. Turn the ignition OFF.
2. Connect a test light between the cooling fan
relay Hi connector terminal 30 and ground.
Is the test light on?–Go to Step 35Go to Step 45
351. Disconnect the cooling fan control relay.
2. Connect a test light between the cooling fan
control relay connector terminal 85 and ground.
3. Turn the ignition ON.
Is the test light on?–Go to Step 36Go to Step 46
361. Turn the ignition OFF.
2. Connect a test light between the cooling fan
control relay connector terminal 87 and battery
positive.
Is the test light on?–Go to Step 37Go to Step 47
371. Connect the main cooling fan connector.
2. Connect the cooling fan relay Hi.
3. Connect the cooling fan control relay.
4. Disconnect the ECM connector.
5. Connect a fused jumper between the ECM
connector terminal 10 and ground.
6. Connect a fused jumper between the ECM
connector terminal 9 and ground.
7. Turn the ignition ON.
Do the cooling fans run at high speed?–Go to Step 30Go to Step 38
381. Turn the ignition OFF.
2. Check for an open wire between the cooling
fan relay Hi connector terminal 85 and the
ECM connector terminal 9.
Is the problem found?–Go to Step 22Go to Step 39
391. Disconnect the cooling fan relay Hi.
2. Connect a test light between the cooling fan
relay Hi connector terminal 87 and battery posi-
tive.
Is the test light on?–Go to Step 40Go to Step 48
401. Disconnect the ECM connector.
2. Connect a fused jumper between the ECM
connector terminal 9 and ground.
3. Disconnect the cooling fan relay Hi.
4. Connect a test light between the cooling fan
control relay connector terminal 86 and battery
positive.
Is the test light on?–Go to Step 41Go to Step 49

1F – 98IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
411. Connect the cooling fan control relay.
2. Connect a fused jumper between the ECM
connector terminal 9 and ground.
3. Disconnect the cooling fan relay Hi.
4. Connect a fused jumper between the cooling
fan relay Hi connector terminals 30 and 87.
5. Disconnect the low speed cooling fan relay.
6. Connect a fused jumper between the low
speed cooling fan relay connector terminals 30
and 87.
7. Turn the ignition ON.
Do the cooling fans run at high speed?–Go to Step 43Go to Step 42
421. Turn the ignition OFF.
2. Connect a fused jumper between the ECM
connector terminal 9 and ground.
3. Disconnect the cooling fan control relay.
4. Connect a fused jumper between the cooling
fan control relay connector terminals 30 and
87.
5. Connect a fused jumper between the low
speed cooling fan relay connector terminals 30
and 87.
6. Turn the ignition ON.
Do the cooling fans run at high speed?–Go to Step 27–
43Replace the cooling fan relay Hi.
Is the repair complete?–System OK–
44Repair the open wire between the cooling fan relay
Hi connector terminal 86 and the ignition switch.
Is the repair complete?–System OK–
45Repair the open wire between the cooling fan relay
Hi connector terminal 30 and the battery.
Is the repair complete?–System OK–
46Repair the open wire between the cooling fan control
relay connector terminal 85 and the ignition switch
Is the repair complete?–System OK–
47Repair the open wire between the cooling fan control
relay connector terminal 87 and ground.
Is the repair complete?–System OK–
48Repair the open wire between the cooling fan relay
Hi connector terminal 87 and the auxiliary cooling
fan connector terminal 2.
Is the repair complete?–System OK–
49Repair the open wire between the cooling fan control
relay connector terminal 85 and the ECM connector
terminal 9.
Is the repair complete?–System OK–

ENGINE CONTROLS 1F – 99
DAEWOO V–121 BL4

1F – 100IENGINE CONTROLS
DAEWOO V–121 BL4
ENGINE COOLING FAN CIRCUIT CHECK – DUAL FAN
(1.8L DOHC)
Circuit Description
The engine cooling fan circuit operates the main cooling
fan and the auxiliary cooling fan. The cooling fans are con-
trolled by the engine control module (ECM) based on in-
puts from the Engine Coolant Temperature (ECT) sensor
and the Air Conditioning Pressure (ACP) sensor. The
ECM controls the low speed cooling fan operation by inter-
nally grounding the ECM connector terminal K28. This en-
ergizes the low speed cooling fan relay and operates the
main cooling fan and the auxiliary cooling fan at low speed
as the cooling fans are connected in a series circuit. The
ECM controls the high speed cooling fan operation by in-
ternally grounding the ECM connector terminal K28 and
the ECM connector terminal K12 at the same time. This
energizes the low speed cooling fan relay, the high speed
cooling fan relay, and the series/parallel cooling fan relay
resulting in high speed fan operation as the cooling fans
are now connected in a parallel circuit.
Diagnostic Aids
S If the owner complained of an overheating problem,
it must be determined if the complaint was due to
an actual boil over, or the engine coolant tempera-
ture gauge indicated overheating. If the engine is
overheating and the cooling fans are on, the cooling
system should be checked.
S If the engine fuse block fuses Ef21, Ef6, Ef8 be-
come open (blown) immediately after installation,
inspect for a short to ground in the wiring of the ap-
propriate circuit. If the fuses become open (blown)
when the cooling fans are to be turned on by the
ECM, suspect a faulty cooling fan motor.
S The ECM will turn the cooling fans on at low speed
when the coolant temperature is 97°C (207°F). The
ECM will turn the cooling fans off when the coolant
temperature is 94°C(201°F).
S The ECM will turn the cooling fans on at high speed
when the coolant temperature is 101°C (214°F).
The ECM will change the cooling fans from high
speed to low speed when the coolant temperature
is 98°C (208°F).S The ECM will turn the cooling fans on at low speed
when the A/C system is on. The ECM will change
the cooling fans from low speed to high speed
when the high side A/C pressure is 1882 kPa (273
psi) then return to low speed when the high side
A/C pressure is 1448 kPa (210 psi). When the A/C
system is on, the ECM will change the cooling fans
from low to high speed when the coolant tempera-
ture reaches 117°C (244°F) then return to low
speed when the coolant temperature reaches
11 4°C (237°F).
S The cooling fan circuit can be checked quickly by
disconnecting the ECM connector 2 and grounding
the connector terminal K28. This should create low
speed cooling fan operation with the ignition ON. By
grounding the ECM connector terminals K28 and
K12 and turning the ignition ON, high speed cooling
fan operation should be achieved.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
4. This step, along with step 5, checks for the ability of
the ECM to operate the cooling fans.
8. This step, along with step 9, checks for the ability of
the ECM to operate the cooling fans in response to
A/C pressure readings.
16. After confirming battery voltage and the ECM sup-
plying a ground to the coil side of the cooling fan
relay A, by jumpering connector terminals 30 and
87 it will be determined if the relay is at fault or a
wiring problem is present.
31. This step checks for the presence of battery volt-
age to the main cooling fan when the A/C is on. If
battery voltage is present and the cooling fans are
not operating, the problem is in the ground side of
the cooling fan circuit.
37. By directly grounding the ECM connector terminals
K28 and K12, the main and auxiliary cooling fans
should run at high speed.
Engine Cooling Fan Circuit Check – Dual Fan (1.8L DOHC)
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) system
check.
Is the check completed?–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Check the I/P fuse block fuse F2.
2. Replace the fuse as needed.
Is the fuse OK?–Go to Step 3Go to
”Diagnostic
Aids”

ENGINE CONTROLS 1F – 101
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
31. Check the engine fuse block fuse Ef21, Ef6,
Ef8.
2. Replace the fuse as needed.
Is the fuse OK?–Go to Step 4Go to
”Diagnostic
Aids”
41. Turn the ignition OFF.
2. Turn the A/C switch OFF.
3. Connect a scan tool to the data link connector
(DLC).
4. The cooling fans should run at low speed when
the coolant temperature reaches 97°C
(207°F).
Do the cooling fans run at low speed?–Go to Step 5Go to Step 10
51. Turn the ignition OFF.
2. Turn the A/C switch OFF.
3. Connect a scan tool to the DLC.
4. Start the engine.
5. The cooling fans should run at high speed
when the coolant temperature reaches 101°C
(214°F).
Do the cooling fans run at high speed?–Go to Step 6Go to Step 33
61. Turn the ignition OFF.
2. Start the engine.
3. Turn the A/C switch ON.
Does the A/C compressor clutch engage?–Go to Step 8Go to Step 7
71. Diagnose the A/C compressor clutch circuit.
2. Repair the A/C compressor clutch circuit as
needed.
3. Start the engine.
4. Turn the A/C switch ON.
Does the A/C compressor clutch engage?–Go to Step 8–
8Do the cooling fans run at low speed?–Go to Step 9Go to Step 31
91. Turn the ignition OFF.
2. Connect the A/C pressure gauges.
3. Start the engine.
4. Turn the A/C switch ON.
5. The cooling fans should run at high speed
when the high side A/C pressure reaches 1
882 kPa (273 psi).
Do the cooling fans run at high speed?–Go to Step 10–
101. Turn the ignition OFF.
2. Connect a scan tool to the DLC.
3. The coolant temperature should be above
97°C (207°C).
4. Disconnect the main cooling fan connector.
5. Turn the ignition ON.
6. Connect a test light between the main cooling
fan connector terminal 2 and ground.
Is the test light on?–Go to Step 11Go to Step 12

1F – 102IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
111. Turn the ignition OFF.
2. Connect a scan tool to the DLC.
3. The coolant temperature should be above
97°C (207°C).
4. Disconnect the main cooling fan connector.
5. Connect a test light between the main cooling
fan connector terminal 1 and ground.
Is the test light on?–Go to Step 28Go to Step 17
121. Turn the ignition OFF.
2. Disconnect the cooling fan relay Low.
3. Connect a test light between the cooling fan
relay Low connector terminal 85 and ground.
4. Turn the ignition ON.
Is the test light on?–Go to Step 13Go to Step 24
131. Turn the ignition OFF.
2. Connect the cooling fan relay Low.
3. Disconnect engine control module (ECM) white
connector.
4. Connect a fused jumper between the ECM
connector terminal K28 and ground.
5. Turn the ignition ON.
Do the cooling fans run at low speed?–Go to Step 30Go to Step 14
14Check for an open wire between the low speed cool-
ing fan relay connector terminal 85 and the ECM
connector terminal K28.
Is the problem found?–Go to Step 25Go to Step 15
151. Turn the ignition OFF.
2. Disconnect the cooling fan relay Low.
3. Connect a test light between the cooling fan
relay Low connector terminal 30 and ground.
Is the test light on?–Go to Step 16Go to Step 23
16Connect a fused jumper between the cooling fan
relay Low connector terminals 30 and 87.
Do the cooling fans run at low speed?–Go to Step 26Go to Step 17
171. Disconnect the cooling fan control relay.
2. Connect a fused jumper between the cooling
fan relay Low connector terminals 30 and 87.
3. Connect a fused jumper between the cooling
fan control relay connector terminals 30 and
87.
Do the cooling fans run at low speed?–Go to Step 27Go to Step 18
18Check the wire between the cooling fan relay Low
connector terminal 87 to the main cooling fan con-
nector terminal 2 for an open.
Is the problem found?–Go to Step 22Go to Step 19
19Check the wire between the main cooling fan con-
nector terminal 1 and the cooling fan control relay
connector terminal 30 for an open.
Is the problem found?–Go to Step 22Go to Step 20

ENGINE CONTROLS 1F – 103
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
20Check the wire between the cooling fan control relay
connector terminal 87A and the auxiliary cooling fan
connector terminal 2 for an open.
Is the problem found?–Go to Step 22Go to Step 21
21Check for an open wire between the auxiliary cooling
fan connector terminal 1 and ground.
Is the problem found?–Go to Step 22Go to Step 29
22Repair the open wire as needed.
Is the repair complete?–System OK–
23Repair the open between the cooling fan relay Low
connector terminal 30 and the fuse Ef21.
Is the repair complete?–System OK–
24Repair the open between the cooling fan relay Low
connector terminal 86 and the ignition switch.
Is the repair complete?–System OK–
25Repair the open wire between the cooling fan relay
Low connector terminal 85 and the ECM connector
terminal K28.
Is the repair complete?–System OK–
26Replace the cooling fan relay Low.
Is the repair complete?–System OK–
27Replace the cooling fan control relay.
Is the repair complete?–System OK–
28Replace the main cooling fan.
Is the repair complete?–System OK–
29Replace the auxiliary cooling fan.
Is the repair complete?–System OK–
30Replace the ECM.
Is the repair complete?–System OK–
311. Turn the ignition OFF.
2. Disconnect the main cooling fan connector.
3. Connect a test light between the main cooling
fan connector termina 2 and ground.
4. Turn the A/C switch ON.
5. Start the engine.
Is the test light on?–Go to Step 32Go to Step 12
321. Turn the ignition OFF.
2. Connect a test light between the main cooling
fan connector terminal 1 and battery positive.
3. Turn the A/C switch ON.
4. Start the engine.
Is the test light on?–Go to Step 28Go to Step 17
331. Turn the ignition OFF.
2. Disconnect the cooling fan relay Hi.
3. Connect a test light between the cooling fan
relay Hi connector terminal 86 and ground.
4. Turn the ignition ON.
Is the test light on?–Go to Step 34Go to Step 44

1F – 104IENGINE CONTROLS
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
341. Turn the ignition OFF.
2. Connect a test light between the cooling fan
relay Hi connector terminal 30 and ground.
Is the test light on?–Go to Step 35Go to Step 45
351. Disconnect the cooling fan control relay.
2. Connect a test light between the cooling fan
control relay connector terminal 85 and ground.
3. Turn the ignition ON.
Is the test light on?–Go to Step 36Go to Step 46
361. Turn the ignition OFF.
2. Connect a test light between the cooling fan
control relay connector terminal 87 and battery
positive.
Is the test light on?–Go to Step 37Go to Step 47
371. Connect the main cooling fan connector.
2. Connect the cooling fan relay Hi.
3. Connect the cooling fan control relay.
4. Disconnect the ECM connector.
5. Connect a fused jumper between the ECM
connector terminal K28 and ground.
6. Connect a fused jumper between the ECM
connector terminal K12 and ground.
7. Turn the ignition ON.
Do the cooling fans run at high speed?–Go to Step 30Go to Step 38
381. Turn the ignition OFF.
2. Check for an open wire between the cooling
fan relay Hi connector terminal 85 and the
ECM connector terminal K12.
Is the problem found?–Go to Step 22Go to Step 39
391. Disconnect the cooling fan relay Hi.
2. Connect a test light between the cooling fan
relay Hi connector terminal 87 and battery posi-
tive.
Is the test light on?–Go to Step 40Go to Step 48
401. Disconnect the ECM connector.
2. Connect a fused jumper between the ECM
connector terminal K12 and ground.
3. Disconnect the cooling fan relay Hi.
4. Connect a test light between the cooling fan
control relay connector terminal 86 and battery
positive.
Is the test light on?–Go to Step 41Go to Step 49