sensor NISSAN PATROL 1998 Y61 / 5.G Heather And Air Conditioner User Guide

SYSTEM DESCRIPTION
Component parts
Mode door control system components are:
1) Auto amp.
2) Mode door motor (LCU)
3) In-vehicle sensor
4) Ambient sensor
5) Sunload sensor
6) Intake sensor
System 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.
SHA006FA
TROUBLE DIAGNOSESAUTO
Mode Door Motor (Cont'd)
HA-76

SYSTEM DESCRIPTION
Component parts
Air mix door control system components are:
1) Auto amp.
2) Air mix door motor (LCU)
3) In-vehicle sensor
4) Ambient sensor
5) Sunload sensor
6) Intake sensor
System 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.
RHA424GB
TROUBLE DIAGNOSESAUTO
Air Mix Door Motor (Cont'd)
HA-80

SYSTEM DESCRIPTION
Component parts
Intake door control system components are:
1) Auto amp.
2) Intake door motor
3) A/C LAN system (PBR built-in mode motor and air mix door motor)
4) In-vehicle sensor
5) Ambient sensor
6) Sunload sensor
7) Intake sensor
System operation
The intake door control determines intake door position based on the ambient temperature, the intake air
temperature and the in-vehicle temperature. When the A/C, DEFROSTER, or OFF switches are pushed, the
auto ampli®er sets the intake door at the ``Fresh'' position.
RHA640G
TROUBLE DIAGNOSESAUTO
Intake Door Motor (Cont'd)
HA-83

SYSTEM DESCRIPTION
Component parts
Fan speed control system components are:
1) Auto amp.
2) Fan control amp.
3) A/C LAN system (PBR built in mode door motor and air mix door motor)
4) In-vehicle sensor
5) Ambient sensor
6) Sunload sensor
7) Intake sensor
System operation
Automatic mode
In the automatic mode, the blower motor speed is calculated by the automatic ampli®er based on inputs from
the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor. The blower motor applied
voltage ranges from approximately 5 volts (lowest speed) to 12 volts (highest speed).
The control blower speed (in the range of 5 to 12V), the automatic ampli®er supplies a gate voltage to the fan
control ampli®er. Based on this voltage, the fan control ampli®er controls the 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 50ÉC, 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 55ÉC,
at which time the blower speed will increase to the objective speed.
Start up from normal or ``HOT SOAK'' condition (Automatic mode)
The blower will begin operation momentarily after the AUTO button is pushed. 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).
SHA006FB
TROUBLE DIAGNOSESAUTO
Blower Motor (Cont'd)
HA-87

SYSTEM DESCRIPTION
Auto ampli®er controls compressor operation by ambient tempera-
ture and signal from ECM (ECCS control module).
Low temperature protection control
Auto ampli®er will turn the compressor ``ON'' or ``OFF'' as deter-
mined by a signal detected by ambient sensor.
When ambient temperatures are greater than 1ÉC, the compressor
turns ``ON''. The compressor turns ``OFF'' when ambient tempera-
tures are less than þ2ÉC.
RHA094GA
TROUBLE DIAGNOSESAUTO
Magnet Clutch (Cont'd)
HA-93

Ambient Sensor
COMPONENT DESCRIPTION
The ambient sensor is attached in front of the driver's side con-
denser. It detects ambient temperature and converts it into a resis-
tance value which is then input into the auto ampli®er.
AMBIENT TEMPERATURE INPUT PROCESS
The automatic ampli®er includes a ``processing circuit'' for the ambi-
ent sensor input. However, when the temperature detected by the
ambient sensor increases quickly, the processing circuit retards the
auto amp. function. It only allows the auto amp. to recognize an
ambient temperature increase of 0.33ÉC per 100 seconds.
As an example, consider stopping for a cup of coffee after high
speed driving. Although the actual ambient temperature has not
changed, the temperature detected by the ambient sensor will
increase. This is because the heat from the engine compartment
can radiate to the front grille area, location of the ambient sensor.
RHA670G
TROUBLE DIAGNOSESAUTO
HA-103

DIAGNOSTIC PROCEDURE
SYMPTOM: Ambient sensor circuit is open or shorted. (orA/C LEDis indicated on auto amp. as a result of conducting
Self-diagnosis STEP 2.)
CHECK AMBIENT SENSOR CIRCUIT
BETWEEN AMBIENT SENSOR AND
AUTO AMP.
Disconnect ambient sensor harness con-
nector.
Do approx. 5 volts exist between ambient
sensor harness terminal No.j
9and body
ground?
Ye s
cNo
Disconnect auto amp. har-
ness connector.
Note
Check circuit continuity
between ambient sensor
harness terminal No.j
9
and auto amp. harness
terminal No.j
9.
OK
Disconnect auto amp. harness connector.
Replace auto amp.
Note
Check circuit continuity between ambient
sensor harness terminal No.j
24and auto
amp. harness terminal No.j
24.
OK
CHECK AMBIENT SENSOR.
(Refer to HA-105.)
OK
cNG
Replace ambient sensor.
Replace auto amp.
Note:
If the result is NG or No after checking circuit continuity, repair harness
or connector.
RHA051GC
RHA671G
RHA672G
RHA673G
.
..
.
.
.
TROUBLE DIAGNOSESAUTO
Ambient Sensor (Cont'd)
HA-104

COMPONENT INSPECTION
Ambient sensor
After disconnecting ambient sensor harness connector, measure
resistance between terminalsj
9andj24at sensor harness side,
using the table below.
Temperature ÉC (ÉF) Resistance kW
þ15 (5) 12.73
þ10 (14) 9.92
þ5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27
45 (113) 1.07
In-vehicle Sensor
COMPONENT DESCRIPTION
In-vehicle sensor
The in-vehicle sensor is located on instrument lower panel. It con-
verts variations in temperature of compartment air drawn from the
aspirator into a resistance value. It is then input into the auto ampli-
®er.
Aspirator
The aspirator is located in front of heater unit. It produces vacuum
pressure due to air discharged from the heater unit, continuously
taking compartment air in the aspirator.
RHA674G
RHA675G
RHA636F
RHA482A
TROUBLE DIAGNOSESAUTO
Ambient Sensor (Cont'd)
HA-105

DIAGNOSTIC PROCEDURE
SYMPTOM: In-vehicle sensor circuit is open or shorted.
(
orA/C LEDis indicated on auto amp. as a result of con-
ducting Self-diagnosis STEP 2.)
CHECK IN-VEHICLE SENSOR CIRCUIT
BETWEEN IN-VEHICLE SENSOR AND
AUTO AMP.
Disconnect in-vehicle sensor harness con-
nector.
Do approx. 5 volts exist between in-ve-
hicle sensor harness terminal No.j
8and
body ground?
Ye s
cNo
Disconnect auto amp. har-
ness connector.
Note
Check circuit continuity
between in-vehicle sensor
harness terminal No.j
8
and auto amp. harness
terminal No.j
8.
OK
Disconnect auto amp. harness connector.
Replace auto amp.
Note
Check circuit continuity between in-vehicle
sensor harness terminal No.j
24and auto
amp. harness terminal No.j
24.
OK
CHECK IN-VEHICLE SENSOR.
(Refer to HA-107.)
OK
cNG
Replace in-vehicle sensor.
Replace auto amp.
Note:
If the result is NG or No after checking circuit continuity, repair harness
or connector.
RHA056GE
RHA676G
RHA677G
RHA678G
.
..
.
.
.
TROUBLE DIAGNOSESAUTO
In-vehicle Sensor (Cont'd)
HA-106

COMPONENT INSPECTION
In-vehicle sensor
After disconnecting in-vehicle sensor harness connector, measure
resistance between terminalsj
8andj24at sensor harness side,
using the table below.
Temperature ÉC (ÉF) Resistance kW
þ15 (5) 12.73
þ10 (14) 9.92
þ5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27
45 (113) 1.07
Sunload Sensor
COMPONENT DESCRIPTION
The sunload sensor is located on the right defroster grille. It detects
sunload entering through windshield by means of a photo diode.
The sensor converts the sunload into a current value which is then
input into the auto ampli®er.
SUNLOAD INPUT PROCESS
The auto amp. also includes a processing circuit which ``average''
the variations in detected sunload over a period of time. This pre-
vents drastic swings in the ATC system operation due to small or
quick variations in detected sunload.
For example, consider driving along a road bordered by an occa-
sional group of large trees. The sunload detected by the sunload
sensor will vary whenever the trees obstruct the sunlight. The pro-
cessing circuit averages the detected sunload over a period of time,
so that the (insigni®cant) effect of the trees momentarily obstruct-
ing the sunlight does not cause any change in the ATC system
operation. On the other hand, shortly after entering a long tunnel,
the system will recognize the change in sunload, and the system
will react accordingly.
RHA679G
RHA682G
TROUBLE DIAGNOSESAUTO
In-vehicle Sensor (Cont'd)
HA-107