1998 NISSAN PATROL stop start

SYSTEM DESCRIPTION
Intake door motor
The intake door motor is installed on the intake unit. Using a link it
opens and closes the intake door.
When RECIRCULATION switch is at REC, the ground line of the
motor is switched from terminalj
14toj13. This starts the motor
because the position switch contacts built into it make current flow.
When RECIRCULATION switch is at FRE, the ground line is
switched from terminalj
13toj14. The contacts turn along with the
motor. When they reach the non-current ¯ow position, the motor will
stop. The motor always turns in the same direction.
RHA589G
TROUBLE DIAGNOSESMANUAL
Intake Door Motor (Cont'd)
HA-25

Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.
AC354A
+Air conditioner system does
not function and does not
cyclically cool the compart-
ment air.
+The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.Refrigerant does not discharge
cyclically.
¯
Moisture is frozen at expansion
valve outlet and inlet.
¯
Water is mixed with refrigerant.+Drain water from refrigerant
or replace refrigerant.
+Replace liquid tank.
Low-pressure side becomes
negative.
AC362A
Liquid tank or front/rear side of
expansion valve's pipe is
frosted or dewed.High-pressure side is closed
and refrigerant does not ¯ow.
¯
Expansion valve or liquid tank
is frosted.Leave the system at rest. Start
it again to check whether or not
the problem is caused by water
or foreign particles.
+If water is the cause, initially
cooling is okay. Then the
water freezes, causing a
blockage. Drain water from
refrigerant or replace refriger-
ant.
+If due to foreign particles,
remove expansion valve and
remove the particles with dry
and compressed air.
+If either of the above meth-
ods cannot correct the
problem, replace expansion
valve.
+Replace liquid tank.
+Check lubricant for contami-
nation.
TROUBLE DIAGNOSESMANUAL
Trouble Diagnoses for Abnormal Pressure
(Cont'd)
HA-38

Operation
The auto ampli®er receives data from each of the sensors. The ampli®er sends air mix door and mode door
opening angle data to the air mix door motor LCU and mode door motor LCU.
The air mix door motor and mode door motor read their respective signals according to the address signal.
Opening angle indication signals received from the auto ampli®er and each of the motor position sensors are
compared by the LCUs in each motor with the existing decision and opening angles. Subsequently, HOT/
COLD or DEFROST/VENT operation is selected. The new selection data is returned to the auto ampli®er.
Transmission data and transmission order
Ampli®er data is transmitted consecutively to each of the door motors following the form shown in ®gure below.
Start: Initial compulsory signal sent to each of the door motors.
Address: Data sent from the auto ampli®er is selected according to data-based decisions made by the air mix
door motor and mode door motor.
If the addresses are identical, the opening angle data and error check signals are received by the door motor
LCUs. The LCUs then make the appropriate error decision. If the opening angle data is normal, door control
begins.
If an error exists, the received data is rejected and corrected data received. Finally, door control is based upon
the corrected opening angle data.
Opening angle: Data that shows the indicated door opening angle of each door motor.
Error check: Procedure by which sent and received data is checked for errors. Error data is then compiled.
The error check prevents corrupted data from being used by the air mix door motor and mode door motor.
Error data can be related to the following problems.
+Abnormal electrical frequency
+Poor electrical connections
+Signal leakage from transmission lines
+Signal level ¯uctuation
Stop signal: At the end of each transmission, a stop operation, in-operation, or internal problem message is
delivered to the auto ampli®er. This completes one data transmission and control cycle.
RHA441GA
DESCRIPTIONAUTO
Features (Cont'd)
HA-50

Maintenance of Lubricant Quantity in
Compressor
The lubricant used to lubricate the compressor circulates through
the system with the refrigerant. Add lubricant to compressor when
replacing any component or after a large gas leakage occurred. It
is important to maintain the speci®ed amount.
If lubricant quantity is not maintained properly, the following mal-
functions may result:
+Lack of lubricant: May lead to a seized compressor
+Excessive lubricant: Inadequate cooling (thermal exchange
interference)
LUBRICANT
Name: Nissan A/C System Oil Type S
Part number: KLH00-PAGS0
CHECKING AND ADJUSTING
Adjust the lubricant quantity according to the ¯owchart shown
below.
START
Can lubricant return operation be per-
formed?
+A/C system works properly.
+There is no evidence of a large amount of
lubricant leakage.
No
cYe s
Perform lubricant return operation, proceeding as follows:
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1. Start engine, and set the following conditions:
+Test condition
Engine speed: Idling to 1,200 rpm
A/C or AUTO switch: ON
Blower speed: Max. position
Temp. control: Optional [Set so that intake air temperature is
25 to 30ÉC (77 to 86ÉF).]
2. Perform lubricant return operation for about 10 minutes.
3. Stop engine.
CAUTION:
If excessive lubricant leakage is noted, do not perform the lubricant
return operation.
Should the compressor be replaced?
No Yes
b
jA(Go to next page.)
Is there any part to be replaced?
(Evaporator, condenser, liquid tank or in
case there is evidence of a large amount of
lubricant leakage.)
No
cYe s
After replacing any of the following major components, add the correct
amount of lubricant to the system.
Amount of lubricant to be added
*1: If compressor is replaced, addition of lubricant is included in the ¯ow
chart.
*2: If refrigerant leak is small, no addition of lubricant is needed.
Carry out the A/C performance test.b
Part replacedLubricant to be added to sys-
tem
Remarks
Amount of lubricant
m!(Imp ¯ oz)
Evaporator 75 (2.6) Ð
Condenser 75 (2.6) Ð
Liquid tank 5 (0.2)Add if compressor is not
replaced. *1
In case of refrigerant leak30 (1.1) Large leak
Ð Small leak*2
.
.
.
.
.
SERVICE PROCEDURESMANUAL AND AUTO
HA-114

3. Move probe along component approximately 25 to 50 mm (1 to
2 in)/sec.
CHECKING PROCEDURE
To prevent inaccurate or false readings, make sure there is no
refrigerant vapor or tobacco smoke in the vicinity of the
vehicle. Perform the leak test in calm area (low air/wind move-
ment) so that the leaking refrigerant is not dispersed.
1. Turn engine off.
2. Connect a suitable A/C manifold gauge set to the A/C service
ports.
3. Check if the A/C refrigerant pressure is at least 345 kPa (3.452
bar, 3.52 kg/cm
2, 50 psi) above 16ÉC (61ÉF). If less than
speci®cation, evacuate and recharge the system with the speci-
®ed amount of refrigerant.
NOTE: At temperatures below 16ÉC (61ÉF), leaks may not be
detected since the system may not reach 345 kPa
(3.452 bar, 3.52 kg/cm
2, 50 psi).
4. Conduct the leak test from the high side to the low side at points
in alphabetical order (j
a,jb......). Refer to HA-117.
Perform a leak check for the following areas carefully. Clean the
component to be checked and move the leak detector probe
completely around the connection/component.
+Compressor
Check the ®tting of high and low pressure hoses, relief valve
and shaft seal.
+Liquid tank
Check the pressure switch, tube ®tting, weld seams and the
fusible plug mounts.
+Service valves
Check all around the service valves. Ensure service valve caps
are secured on the service valves (to prevent leaks).
NOTE: After removing A/C manifold gauge set from service
valves, wipe any residue from valves to prevent any
false readings by leak detector.
+Cooling unit (Evaporator)
Turn blower fan on ``High'' for at least 15 seconds to dissipate
any refrigerant trace in the cooling unit. Insert the leak detector
probe into the drain hose immediately after stopping the
engine. (Keep the probe inserted for at least ten seconds.)
5. If a leak detector detects a leak, verify at least once by blowing
compressed air into area of suspected leak, then repeat check.
6. Do not stop when one leak is found. Continue to check for
additional leaks at all system components.
7. Start engine.
8. Set the heater A/C control as follows:
a. A/C switch ON
b. Face mode
c. Recirculation switch ON
d. Max cold temperature
e. Fan speed high
SHA708EA
SERVICE PROCEDURESMANUAL AND AUTO
Checking Refrigerant Leaks (Cont'd)
HA-120