2003 NISSAN TEANA coolant temperature

ATC-26
AIR CONDITIONER CONTROL

Stop Signal:
At the end of each transmission, a stop operation, in-operation, or internal malfunction message is delivered to
the unified meter and A/C amp. This completes one data transmission and control cycle.
AIR MIX DOOR CONTROL (AUTOMATIC TEMPERATURE CONTROL)
The air mix doors are automatically controlled so that in-vehicle temperature is maintained at a predetermined
value by the temperature setting, ambient temperature, in-vehicle temperature and amount of sunload.
FAN SPEED CONTROL
Blower speed is automatically controlled by the temperature setting, ambient temperature, in-vehicle tempera-
ture, intake temperature, amount of sunload and air mix door position.
With pressing AUTO switch, the blower motor starts to gradually increase air flow volume.
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.
INTAKE DOOR CONTROL
The intake doors are automatically controlled by the temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of sunload and ON/OFF operation of the compressor.
MODE DOOR CONTROL
The mode door is automatically controlled by the temperature setting, ambient temperature, in-vehicle temper-
ature, intake temperature and amount of sunload.
RJIA1749E

TROUBLE DIAGNOSIS
ATC-73
C
D
E
F
G
H
I
K
L
MA
B
AT C

SYSTEM DESCRIPTION
Component Parts
Fan speed control system components are:

Unified meter and A/C amp.

A/C LAN system (PBR built-in mode door motor, air mix door motor and intake motor)

Fan control amp.

In-vehicle sensor

Ambient sensor

Sunload sensor

Intake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed control signal is calculated by the unified meter and A/C amp.
based on the input from the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor.
The blower motor applied voltage ranges from approximately 3.5 volts (lowest speed) to 12 volts (highest
speed).
The control blower speed (in the range of 3.5 to 12 V), unified meter and A/C amp. supplies a gate voltage to
the fan control amp. Based on this voltage, fan control amp. controls voltage supplied to the blower motor.
Starting Fan Speed Control
Start up from COLD SOAK Condition (Automatic mode)
In a cold start up condition where the engine coolant temperature is below 56°C (133°F), the blower will not
operate for a short period of time (up to 150 seconds). The exact start delay time varies depending on the
ambient and engine coolant temperature.
In the most extreme case (very low ambient) the blower starting delay will be 150 seconds as described
above. After this delay, the blower will operate at low speed until the engine coolant temperature rises above
56°C (133°F), and then the blower speed will increase to the objective speed.
Start up from usual or HOT SOAK Condition (Automatic mode)
The blower will begin operation momentarily after the AUTO switch is pressed. The blower speed will gradu-
ally rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
RJIA3262E

CO-12
[QR]
ENGINE COOLANT

8. Warm up until opening thermostat and water control valve. Standard for warming-up time is approximately
10 minutes at 3,000 rpm.

Make sure thermostat opening condition by touching radiator hose (lower) to see a flow of warm water.
CAUTION:
Watch water temperature gauge so as not to overheat engine.
9. Stop engine and cool down to less than approximately 50°C (122°F).

Cool down using fan to reduce the time.

If necessary, refill radiator up to filler neck with engine coolant.
CAUTION:
Never adhere the engine coolant to electronic equipments (alternator etc.).
10. Refill reservoir tank to “MAX” level line with engine coolant.
11. Repeat steps 3 through 9 two or more times with radiator cap installed until engine coolant level no longer
drops.
12. Check cooling system for leaks with engine running.
13. Warm up engine, and check for sound of engine coolant flow while running engine from idle up to 3,000
rpm with heater temperature controller set at several position between “COOL” and “WARM”.

Sound may be noticeable at heater unit.
14. Repeat step 13 three times.
15. If sound is heard, bleed air from cooling system by repeating steps 3 through 9 until engine coolant level
no longer drops.
FLUSHING COOLING SYSTEM
1. Install reservoir tank if removed, and radiator drain plug.
CAUTION:
Be sure to clean drain plug and install with new O-ring.
If water drain plug on cylinder block is removed, close and tighten it. Refer to EM-81, "
CYLINDER
BLOCK" .
2. Remove air duct assembly. Refer to EM-17, "
AIR CLEANER AND AIR DUCT" .
3. Disconnect heater hose (left side of vehicle) at the position in
the figure.

Enhance heater hose as high as possible.
4. Fill radiator and reservoir tank with water and reinstall radiator cap.

When engine coolant overflows disconnected heater hose, connect heater hose, and continue filling the
engine coolant.
5. Install air duct assembly. Refer to EM-17, "
AIR CLEANER AND AIR DUCT" .
6. Run engine and warm it up to normal operating temperature.
7. Rev engine two or three times under no-load.
8. Stop engine and wait until it cools down.
9. Drain water from the system. Refer to CO-10, "
DRAINING ENGINE COOLANT" .
10. Repeat steps 1 through 9 until clear water begins to drain from radiator.Radiator drain plug:
: 1.2 N·m (0.12 kg-m, 11 in-lb)
1 : Heater hose
: Vehicle front
PBIC4679E

CO-24
[QR]
THERMOSTAT AND WATER CONTROL VALVE

THERMOSTAT AND WATER CONTROL VALVEPFP:21200
Removal and InstallationBBS005AB
REMOVAL
1. Drain engine coolant from radiator drain plug at the bottom of radiator and from water drain plug on engine
cylinder block. Refer to CO-10, "
Changing Engine Coolant" and EM-81, "CYLINDER BLOCK" .
CAUTION:

Perform this step when engine is cold.

Do not spill engine coolant on drive belt.
2. Disconnect radiator hose (lower) at water inlet side. Refer to CO-13, "
RADIATOR" .
3. Remove water inlet and thermostat.
4. Remove water control valve with the following procedure:
a. Disconnect radiator hose (upper) at water control valve housing (water outlet) side.
b. Disconnect harness connector from engine coolant temperature sensor.
c. Remove heater pipe and heater hose.
d. After removing water control valve housing (water outlet), remove water control valve.
1. Thermostat 2. O-ring 3. Water inlet
4. Water control valve 5. O-ring 6. Gasket
7. Water control valve housing (water outlet) 8. Washer 9. Engine coolant temperature sensor
10. Heater hose 11. O-ring 12. Heater pipe
13. Heater hose
PBIC3519E

THERMOSTAT AND WATER CONTROL VALVE
CO-25
[QR]
C
D
E
F
G
H
I
J
K
L
MA
CO

INSPECTION AFTER REMOVAL

Place a string so that it is caught in the valves of thermostat and
water control valve. Immerse fully in a container filled with water.
Heat while stirring. (The example in the figure shows thermo-
stat.)

The valve opening temperature is the temperature at which the
valve opens and falls from the thread.

Continue heating. Check the maximum valve lift amount.
NOTE:
The maximum valve lift amount standard temperature for water
control valve is the reference value.

After checking the maximum valve lift amount, lower the water
temperature and check the valve closing temperature.
Standard:

If out of the standard, replace either or both thermostat and water control valve.
INSTALLATION
Note the following, and install in the reverse order of removal.
Thermostat and Water Control Valve

Install thermostat with making rubber ring groove fit to thermo-
stat flange with the whole circumference. (The example in the
figure shows thermostat.)
NOTE:
Same procedure is applied for installation of water control valve.

Install thermostat with jiggle valve facing upwards. (The position
deviation may be within the range of 20 degrees as shown in the
figure.)

Install water control valve with the arrow facing up and the frame
center part facing upwards. (The position deviation may be
within the range of 20 degrees as shown in the figure.)
Heater Pipe Installation
Apply a neutral detergent to O-ring, then quickly insert the insertion part of heater pipe into cylinder block.
INSPECTION AFTER INSTALLATION

Check for leaks of engine coolant using radiator cap tester adapter [SST: EG17650301] and a radiator cap
tester (commercial service tool). Refer to CO-10, "
LEAK CHECK" .

Start and warm up engine. Visually check if there is no leaks of engine coolant and A/T fluid.
SLC252B
Items Thermostat Water control valve
Valve opening temperature 80.5 - 83.5°C (177 - 182°F) 93.5 - 96.5°C (200 - 206°F)
Maximum valve lift 8 mm/ 95°C (0.315 in/ 203°F) 8 mm/ 108°C (0.315 in/ 226°F)
Valve closing temperature 77°C (171°F) 90°C (194°F)
PBIC0157E
PBIC0158E

CO-26
[QR]
SERVICE DATA AND SPECIFICATIONS (SDS)

SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Standard and LimitBBS005AC
ENGINE COOLANT CAPACITY (APPROXIMATE)
Unit: (lmp qt)
THERMOSTAT
WATER CONTROL VALVE
*: Reference data
RADIATOR
Unit: kPa (bar, kg/cm2 , psi)
Engine coolant capacity (With reservoir tank at “MAX” level) 7.4 (6-1/2)
Reservoir tank engine coolant capacity (At “MAX” level) 0.8 (3/4)
Valve opening temperature 80.5 - 83.5°C (177 - 182°F)
Maximum valve lift 8 mm/ 95°C (0.315 in/ 203°F)
Valve closing temperature 77°C (171°F)
Valve opening temperature 93.5 - 96.5°C (200 - 206°F)
Maximum valve lift 8 mm/ 108°C (0.315 in/ 226°F)*
Valve closing temperature 90°C (194°F)
Cap relief pressureStandard 78 - 98 (0.78 - 0.98, 0.8 - 1.0, 11- 14)
Limit 59 (0.59, 0.6, 9)
Leakage test pressure 157 (1.57, 1.6, 23)

CO-36
[VQ]
ENGINE COOLANT

8. Warm up until opening thermostat. Standard for warming-up time is approximately 10 minutes at 3000
rpm.

Make sure thermostat opening condition by touching radiator hose (lower) to see a flow of warm water.
CAUTION:
Watch water temperature gauge so as not to overheat engine.
9. Stop engine and cool down to less than approximately 50°C (122°F).

Cool down using fan to reduce the time.

If necessary, refill radiator up to filler neck with engine coolant.
10. Refill reservoir tank to “MAX” level line with engine coolant.
11. Repeat steps 3 through 9 two or more times with radiator cap installed until engine coolant level no longer
drops.
12. Check cooling system for leaks with engine running.
13. Warm up engine, and check for sound of engine coolant flow while running engine from idle up to 3,000
rpm with heater temperature controller set at several position between “COOL” and “WARM”.

Sound may be noticeable at heater unit.
14. Repeat step 13 three times.
15. If sound is heard, bleed air from cooling system by repeating step 3 through 9 until engine coolant level no
longer drops.
FLUSHING COOLING SYSTEM
1. Install reservoir tank if removed, and radiator drain plug.
CAUTION:
Be sure to clean drain plug and install with new O-ring.
If cylinder block water drain plugs are removed, close and tighten them. Refer to EM-233, "
ASSEM-
BLY" .
2. Remove air duct assembly. Refer to EM-131, "
AIR CLEANER AND AIR DUCT" .
3. Disconnect heater hose (left side of vehicle) at the position in
the figure.

Enhance heater hose as high as possible.
4. Fill radiator and reservoir tank with water and install radiator cap.

When engine coolant overflows disconnected heater hose, connect heater hose, and continue filling the
engine coolant.
5. Install air duct assembly. Refer to EM-131, "
AIR CLEANER AND AIR DUCT" .
6. Run engine and warm it up to normal operating temperature.
7. Rev engine two or three times under no-load.
8. Stop engine and wait until it cools down.
9. Drain water from the system. Refer to CO-34, "
DRAINING ENGINE COOLANT" .
10. Repeat steps 1 through 9 until clear water begins to drain from radiator.Radiator drain plug:
: 1.2 N·m (0.12 kg-m, 11 in-lb)
PBIC2810E

WATER INLET AND THERMOSTAT ASSEMBLY
CO-51
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
CO

INSPECTION AFTER REMOVAL
1. Check valve seating condition at ordinary room temperature. It should seat tightly.
2. Check valve operation.

If the malfunctioning condition, when valve seating at ordinary
room temperature, or measured values are out of the standard,
replace water inlet and thermostat assembly.
INSTALLATION
Note the following, and install in the reverse order of removal.

Be careful not to spill engine coolant over engine room. Use rag to absorb engine coolant.
INSPECTION AFTER INSTALLATION

Check for leaks of engine coolant using radiator cap tester adapter [SST: EG17650301] and radiator cap
tester (commercial service tool). Refer to CO-34, "
LEAK CHECK" .

Start and warm up engine. Visually check if there is no leaks of engine coolant.
Thermostat Standard
Valve opening temperature 80.5 - 83.5°C (177 - 182°F)
Maximum valve lift 8.6 mm / 95°C (0.339 in / 203°F)
Valve closing temperature 77°C (171°F)
SLC949A