2004 DAEWOO NUBIRA check engine

7B – 12IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
V5 SYSTEM AIR CONDITIONING DIAGNOSIS
INSUFFICIENT COOLING DIAGNOSIS
Test Description
The numbers below refer to steps on the diagnostic table.
13. See the Important below.
32. See the Important below.Important : Perform this test under garage conditions with
the air temperature at 21–32°C (70–90°F), and no sun
load. Follow this test carefully for accurate results.
Important : Perform this test exactly as described to ob-
tain accurate results.
Step
ActionValue(s)YesNo
1Record the customer’s complaint.
Can you verify the customer’s complaint?–Go to Step 2System OK
21. Check the A/C fuse.
2. Check the blower fan operation.
3. Check the engine cooling fan operation.
4. Check the A/C compressor belt.
5. Check the A/C condenser for restricted airflow.
6. Check the clutch coil connection.
7. Repair or replace any components as needed.
8. Check the discharge air temperature with the
A/C turned ON.
Is the discharge air temperature normal?At least 7°C
(12°F) below
ambient air
temperatureSystem OKGo to Step 3
31. Turn the ignition switch to LOCK.
2. Connect the high– and the low–pressure
gauges.
Are both pressures within the value specified?69–345 kPa
(10–50 psi)Go to Step 4Go to Step 5
41. Check the A/C system for leaks.
2. Repair any refrigerant leaks as needed.
3. Recover, evacuate, and recharge the A/C sys-
tem.
4. Observe the two pressure gauges.
Are both pressures above the value specified?345 kPa
(50 psi)Go to Step 7–
5Observe the two pressure gauges.
Are both pressures below the value specified?69 kPa
(10 psi)Go to Step 6Go to Step 7
61. Add 0.45 kg (1 pound) of refrigerant R–134a.
2. Check the A/C system for leaks.
3. Repair any refrigerant leaks, as needed.
4. Recover, evacuate, and recharge the A/C sys-
tem.
5. Observe the two pressure gauges.
Are both pressures above the value specified?345 kPa
(50 psi)Go to Step 7–
71. Start the engine and allow it to run at idle.
2. Set the A/C controls to the following positions:
S The A/C switch to the ON.
S The fresh air control switch to fresh air (in-
dicator lamp OFF).
S The blower motor to 4.
S The temperature to full cold.
Does the A/C compressor clutch engage?–Go to Step 8Go to Step 10

MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 13
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
81. Check for a knocking noise from the A/C com-
pressor.
2. Cycle the A/C compressor ON and OFF in or-
der to verify the source of the noise.
Do you hear a loud knocking noise?–Go to Step 9Go to Step 13
91. Recover the A/C system refrigerant.
2. Replace the A/C compressor.
3. Evacuate and recharge the A/C system.
4. Check the A/C system for leaks.
Is the compressor running normally?–Go to Step 13–
101. Turn the ignition switch to LOCK.
2. Disconnect the A/C compressor clutch coil con-
nector.
3. Connect a jumper wire from ground to one A/C
compressor clutch coil terminal.
4. Connect a fused jumper wire from the positive
battery terminal to the other A/C compressor
clutch coil terminal.
Does the A/C clutch engage?–Go to Step 11Go to Step 12
11Repair the electrical circuit to the A/C compressor
clutch coil.
Does the A/C clutch engage?–Go to Step 8–
12Replace the A/C compressor clutch coil.
Does the A/C clutch engage?–Go to Step 8–
131. Close all of the vehicle’s windows and doors.
2. Set the A/C controls to the following positions:
S The A/C switch to the ON position.
S The fresh air control switch to fresh air.
S The blower motor to 4.
S The temperature to full cold.
3. Start the engine and allow it to run at idle for 5
minutes.
4. Feel the evaporator inlet and outlet pipes.
Is there a noticeable difference in the temperature of
the evaporator inlet and outlet pipes?–Go to Step 15Go to Step 14
141. Turn the ignition switch to LOCK.
2. Recover the A/C system refrigerant.
3. Examine the high–pressure pipe for an ob-
struction.
4. Examine the expansion valve for an obstruction
or a malfunction.
5. Repair the obstruction or replace the expansion
valve as needed.
6. Evacuate and recharge the A/C system.
7. Check the A/C system for leaks.
8. Note the discharge air temperature with the
A/C ON.
Is the discharge temperature normal?At least 7°C
(12°F) below
ambient air
temperatureGo to Step 15Go to Step 13

7B – 14IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
151. Record the low– and the high–side pressures
after the A/C system has been operating for 5
minutes or more with the engine cooling fan
ON.
2. Locate the intersection of the low– and the high
side pressures. Refer to ”Low– and High–Side
Pressure Relationship Chart” in this section.
Do the low– and the high–side pressures intersect
in the white area of the chart?–System OKGo to Step 16
16Check the high– and the low–side pressures.
Do the low– and the high–side pressures intersect
in the grey area of the chart?–Go to Step 17Go to Step 20
17Feel the liquid pipe between the condenser and the
expansion valve.
Is the pipe cold?–Go to Step 18Go to Step 19
181. Examine the condenser for any restriction of
the airflow.
2. Check the cooling fans for proper operation.
3. Remove the restriction or repair the fans, as
required.
Is the pipe temperature normal now?At least 7°C
(12°F) below
ambient air
temperatureGo to Step 13–
191. Recover, evacuate, and recharge the A/C sys-
tem.
2. Check the A/C system for leaks.
Is the system free from leaks?–Go to Step 13–
20Observe the readings on the pressure gauges.
Are the A/C compressor high– and the low–side
pressures within the specified value of each other?207 kPa
(30 psi)Go to Step 21Go to Step 26
211. Run the engine at 3,000 rpm.
2. Set the A/C controls to the following positions:
S The A/C switch to the ON.
S The fresh air control switch to fresh air.
S The blower motor to 4.
S The temperature to full cold.
3. Close all of the vehicle’s windows and doors.
4. Turn the A/C switch ON and OFF every 20
seconds for 3 minutes.
Are the A/C compressor high– and the low–side
pressures within the specified value of each other?207 kPa
(30 psi)Go to Step 22Go to Step 13
22Observe the pressure rise on both gauges and the
temperatures of both the compressor suction pipe
and the discharge pipe.
Is the pressure rise on both gauges slow and the
suction pipe warm with the discharge pipe very hot?–Go to Step 25Go to Step 23
231. Turn the ignition switch to LOCK.
2. Make sure the compressor clutch is disen-
gaged.
3. Attempt to turn the clutch driver (not the
pulley).
Can you turn the clutch driver freely by hand?–Go to Step 25Go to Step 24

MANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM 7B – 15
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
241. Start the engine.
2. Observe the low–side pressure gauge while
running the engine between 3,000 and 3,800
rpm.
Does the low–side pressure rise rapidly?–Go to Step 32Go to Step 25
251. Recover the A/C system refrigerant.
2. Replace the A/C compressor.
3. Evacuate and recharge the A/C system.
Is the compressor functioning normally?–Go to Step 13–
26Check the low–side pressure.
Is the low–side pressure within the specified value?172–241 kPa
(25–35 psi)Go to Step 27Go to Step 32
27Feel the high–side pipe leading up to the expansion
valve connecting block.
Is the pipe cold before the connecting block?–Go to Step 28Go to Step 29
281. Check for a restriction in the high–side pipe
before the expansion valve.
2. Repair or replace the high–side pipe.
Is the pipe performing normally?–Go to Step 13–
29Add the specified amount of refrigerant to the A/C
system.
Does the cooling performance improve?0.40 kg
(14 ounces)Go to Step 30Go to Step 31
301. Check the A/C system for leaks.
2. Repair any refrigerant leaks, as needed.
3. Evacuate and recharge the A/C system.
4. Check the A/C system for leaks.
Is the system free from leaks?–Go to Step 13–
311. Recover the refrigerant.
2. Check the expansion valve for obstructions.
3. Repair or replace the expansion valve, as re-
quired.
4. Evacuate and recharge the system.
5. Check the A/C system for leaks.
Is the system free from leaks?–Go to Step 13–
321. Run the engine for 5 minutes at 2,000 rpm.
2. Set the A/C controls to the following positions:
S The A/C switch to the ON position.
S The fresh air control switch to recirculate
(indicator lamp ON).
S The blower motor to 1.
S The temperature to full cold.
3. Close all of the vehicle’s windows and doors.
4. Open the vehicle hood.
Is the low–side pressure within the specified value?172–241 kPa
(25–35 psi)Go to Step 13Go to Step 33
331. Recover the A/C system refrigerant.
2. Replace the A/C compressor control valve.
3. Evacuate and recharge the A/C system.
4. Check the A/C system for leaks.
Is the system free from leaks?–Go to Step 13–

7B – 22IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
Successful Transfer Complete
1. Close the high–side valve on the unit’s control pan-
el. Both valves should be closed.
2. Start the vehicle and the A/C system.
3. Let the engine run until the readings on the high–
side gauge and the low–side gauge stabilize.
4. Compare the readings to the system specifications.
5. Check the evaporator outlet temperature to ensure
that the A/C system is operating within the system
specifications.
6. Keep the A/C running.
7. Close the high–side coupler valve.
8. Disconnect the high–side hose from the vehicle.
9. Open the high–side and low–side valves on the
control panel. The system will quickly draw in refrig-
erant from both hoses through the low–side hose.
10. Close the low–side coupler valve.
11. Disconnect the low–side hose from the vehicle.
Unsuccessful Transfer
Sometimes the total charge does not transfer into the A/C
system. There are two reasons why this may occur:
1. The pressure in the unit’s tank and the pressure in
the A/C system are roughly equal.
S This will cause the transfer to proceed too slow-
ly.
S Refer to the manufacturer’s instructions for the
charging station in use.
2. There was not enough refrigerant in the unit’s tank
to transfer the full charge.
S It is necessary to recover the partial charge of
refrigerant from the vehicle and then evacuate
the A/C system and charge it again.
S Refer to the manufacturer’s instructions for the
charging station in use.

7D – 8IAUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
NO HOT AIR FROM BLOWER
StepActionValue(s)YesNo
1Check the coolant level.
Is the coolant level correct?–Go to Step 3Go to Step 2
2Add coolant as needed.
Is the heater operating?–System OKGo to Step 3
31. Turn the ignition to ON.
2. Observe the temperature indication screen of
the controller.
Does the digit flash on and off?–Go to Step 4Go to Step 5
4Run a self–diagnosis circuit check.
Does the display indicate a defect code?–Go to the table
for the code
that flashesGo to Step 7
5Observe the blower motor operation.
Is the blower motor functioning at all?–Go to Step 6Go to ”Blower
Motor Does
Not Run at All”
6Use the blower push switch to cycle the blower
through its different speeds.
Does the motor function at different speeds?–Go to Step 7Go to ”Code 6
– Power Tran-
sistor Error”
71. Run the blower and operate the MODE push
switch manually.
2. Check for airflow out the various outlets.
Does the air flow from the different outlets as it
should?–Go to Step 9Go to Step 8
81. Remove the heater outlet and check for ob-
structions.
2. Remove any obstructions found.
Is the heater operating?–System OKGo to Step 9
9Observe the air mix door (AMD) motor while chang-
ing the temperature setting from 18 to 32°C (64 to
90°F) and then from 32 to 18°C (90 to 64°F).
Is the AMD motor functioning properly?–Go to Step 10Go to”Code 4 –
Air Mix Door
Error”
10Check the coolant hoses for leaks or kinks.
Are the coolant hoses in good condition?–Go to Step 12Go to Step 11
11Repair any problem with the coolant hoses.
Is the heater operating?–System OKGo to Step 12
12Check the surge tank cap.
Is the surge tank cap in good condition?–Go to Step 14Go to Step 13
13Repair or replace the surge tank cap as needed.
Is the heater operating?–System OKGo to Step 14
141. Set the A/C switch to OFF.
2. Set the temperature control to 32°C (90°F).
3. Set the blower motor speed to full high (all seg-
ments illuminated on the display).
4. Remove the surge tank cap.
5. Start the vehicle and run the engine at idle.
6. Watch for the flow of the coolant when the ther-
mostat opens.
Does the coolant flow?–Go to Step 16Go to Step 15

7D – 12IAUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
BLOWER MOTOR DOES NOT RUN AT ALL
StepActionValue(s)YesNo
11. Turn the ignition to ON.
2. Observe the temperature indication screen of
the controller.
Does the digit go on and off?–Go to Step 2Go to Step 3
2Run a self–diagnosis circuit check.
Does the display indicate a defect code?–Go to the table
for the code
that flashes.–
3Check fuse F7 in the I/P fuse block.
Is this fuse in good condition?–Go to Step 5Go to Step 4
4Replace fuse F7.
Is the repair complete?–System OK–
5Check fuse EF3 in the engine fuse block.
Is this fuse in good condition?–Go to Step 7Go to Step 6
6Replace fuse EF3.
Is the repair complete?–System OK–
71. Turn the ignition switch to ON.
2. Measure the voltage between ground and ter-
minal 87(Violet) of the blower relay.
Is the voltage within the specified value?11–14 vGo to Step 15Go to Step 8
8Measure the voltage between ground and terminal
86 (Brown) at the blower relay.
Is the voltage within the specified value?11–14 vGo to Step 10Go to Step 9

AUTOMATIC TEMPERATURE CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM 7D – 13
DAEWOO V–121 BL4
StepNo Yes Value(s) Action
91. Turn the ignition switch to OFF.
2. Check circuit (Brown) between terminal 86 of
the blower relay to F7 in the I/P fuse block.
3. Repair any problem found in the wiring or ter-
minals at the relay socket or connector C203.
Is the repair complete?–System OK–
10Measure the voltage between ground and terminal
30 (Red) at the blower relay.
Is the voltage within the specified value?11–14 vGo to Step 12Go to Step 11
111. Turn the ignition switch to OFF.
2. Check circuit (Red) between terminal 30 of the
blower relay to EF3 in the engine fuse block.
3. Repair any problem found in the wiring or ter-
minals at the fuse block connector C105, con-
nector C202, or at the relay socket.
Is the repair complete?–System OK–
121. Turn the ignition switch to OFF.
2. Check the continuity in the wiring harness be-
tween the blower relay terminal 85 (Black) and
ground.
Does the ohmmeter show the specified value?
0 ΩGo to Step 14Go to Step 13
13Repair any problem found in terminal 85 at the relay
connector, circuit (Black), Connector C201, or
ground G201.
Is the repair complete?–System OK–
14Replace the blower relay.
Is the repair complete?–System OK–
151. Turn the ignition switch to OFF.
2. Disconnect the wiring harness at the blower
motor.
3. Turn the ignition switch to ON.
4. Measure voltage between ground and blower
connector 1 (Yellow).
Is the voltage within the specified value?11–14 vGo to Step 17Go to Step 16
161. Turn the ignition switch to OFF.
2. Check circuit (Yellow) between blower connec-
tor terminal 1 and blower relay terminal 87.
3. Repair any problem found in the wiring or a
connector terminal at the blower connector,
connector C208, or the blower relay socket.
Is the repair complete?–System OK–
17Measure the resistance between the connector ter-
minals on the blower motor.
Does the resistance match the specified value?
5 ΩGo to Step 19Go to Step 18
18Replace the blower motor.
Is the repair complete?–System OK–
19Measure the resistance of circuit (Violet) between
terminal 2 of the blower connector and terminal 30
of the Max HI relay and terminal 6 of the power tran-
sistor.
Does the resistance match the specified value?
0 ΩGo to Step 21Go to Step 20