sensor NISSAN PRIMERA 1999 Electronic Repair Manual

Measure voltage between terminalsp5andp6at auto air con-
ditioner harness side, using the table below.
Input current
mAOutput voltage
V
05.00
0.14.09
0.23.18
0.32.27
0.41.36
0.50.45
lWhen checking sunload sensor, select a place where
sun shines directly on it.
A/C RELAY
The A/C relay is located on the left side of the engine room.
When the A/C remain and fan switch are ON, the A/C relay
operates and transmits A/C operation signals to ECM.
Control System Auto Amplifier (Auto amp.)
The auto amplifier has a built-in microcomputer which processes
the information sent from the various sensors needed for air
conditioner operation. The air mix door motor and blower motor
are then controlled.
Signals from the various switches and the Potentio Temperature
Control (PTC) are directly entered into the auto amplifier.
SUNLOAD INPUT PROCESS
The auto amp. also includes a processing circuit which ªaver-
agesº the variations in detected sunload over a period of time.
This prevents 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
processing circuit averages the detected sunload over a period
of time, so that the (insignificant) effect of the trees momentarily
obstructing the sunlight does not cause any change in the ATC
NHA289 Auto amplifier
Auto amp.
connectorAuto amp.
connector
NHA298
.A/C Relay
RHA024H Auto amplifier
SYSTEM DESCRIPTIONAUTO
Control System Input Components (Cont'd)
HA-87

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.
SUNLOAD COMPENSATION
The auto amplifier compensates for sunload by altering the air
mix door position and air flow volume according to the amount
of sunload detected by the sunload sensor. When the amount of
sunload is great, the air mix door is moved toward the ªCOLDº
side. Along with this air mix door movement, air flow volume will
also be changed.
YHA296 A/C control panel PTC
In-vehicle sensor
Ambient sensor
Sunload sensorSunload com-
pensation Auto amplifier
Air mix door posi-
tion arithmetic cir-
cuit
Air flow volume
arithmetic circuitAir mix door motor
LOW, MED, HIGH
and AUTO relays
SHA493CA
Air mix door position
compensation amount
Sunload kW (kcal/h, BTU/h)/m2
[kW (kcal/h,BTU/h)/sq ft]
Sunload compensation specifications0.768 (660, 2,619)
[0.0713 (61.31, 243.3)]
SYSTEM DESCRIPTIONAUTO
Control System Auto Amplifier (Auto amp.)
(Cont'd)
HA-88

A/C SWITCH COMPENSATION
The auto amplifier alters the air mix door position and air flow volume according to a signal emitted from the
A/C switch.
When the A/C switch is ªONº, the auto amplifier compensates for the PBR's input signal and moves the air
mix door toward the ªHOTº side.
YHA297 A/C control panel PTC
In-vehicle sensor
Ambient sensor
Sunload sensor
Sunload compensation Auto amplifier
Air mix door position arith-
metic circuit
Output signal pro-
cessAir mix door
motor
PBR
A/C control panel
A/C switch
KHA115
Air mix door opening ratio
(%)
100
15
0
Air mix door position arithmetic value
A/C switchcompensation specifications 0 100 (%)
SYSTEM DESCRIPTIONAUTO
Control System Auto Amplifier (Auto amp.)
(Cont'd)
HA-89

Control System Output Components
AIR MIX DOOR CONTROL (Automatic temperature control)
Component parts
Air mix door control system components are:
1) Auto amplifier
2) Ambient sensor
3) In-vehicle sensor
4) Sunload sensor
5) Air mix door motor (PBR)
6) A/C switch
System operation
The air mix door is automatically controlled so that in-vehicle temperature is maintained to the set tempera-
ture. The temperature set by the PTC (Potentio Temperature Control) and the temperature detected by the
in-vehicle sensor and ambient sensor are compensated by the sunload sensor signal. The auto amplifier then
determines the air mix door position. The air mix door position detected by the PBR is compensated by the
ON-OFF operation of the A/C switch. The air mix door position determined by the auto amplifier is compared
with that detected by the PBR. The auto amplifier then transmits the signal to the air mix door motor in order
to activate it.
KHA116 Auto amplifier
PTC
In-vehicle sensor
Ambient
sensor
sunload
sensor
PBR
A/C switchConstant voltage
transformation
Air mix door posi-
tion arithmetic cir-
cuit
Sunload compen-
sation
Air mix door posi-
tion detection
A/C switch com-
pensationAir mix
door motor
SYSTEM DESCRIPTIONAUTO
HA-90

Air mix door control specifications
SENSOR INPUT PROCESS
The auto amplifier detects the voltage produced by each sensor,
the PBR and fixed resistor. The fixed resistor is built into the auto
amplifier. 12-volt power voltage is first converted to approxi-
mately 5 volts by the constant voltage circuit where it is then
applied to the ground line of the auto amplifier via the fixed
resistor and the sensor. In this manner, the auto amplifier moni-
tors the voltages of the fixed resistor, each sensor and the PBR
to determine sensor input.
SHA497CB A/C switch OFF
A/C switch ON
Voltage (V)
ConditionPTC: 25ÉC (77ÉF)
Fan switch Auto
Withoutsunload
Ambient
temperature ÉC (ÉF)
Air mix door opening angle In vehicle temperature ÉC (ÉF)
0.5 1.0 1.5 2.0 2.5 3.0
PBRresistance (kW)2.4
2.3
2.2
2.1
2.0
1.9
(59) (68) (77) (86) (95) (104)-20 (-4)
-10 (-4)
0 (32)
10(50)
20 (68)
25 (77)
30(86)
40 (104)
54.5
RHA790A Auto amplifier
Constant-voltage
circuit
Fixed resistor
Detection of sen-
sor voltage
Each sensor
SYSTEM DESCRIPTIONAUTO
Control System Output Components (Cont'd)
HA-91

FAN SPEED CONTROL
Component parts
Fan speed control system components are:
1) Auto amplifier
2) In-vehicle sensor
3) Ambient sensor
4) Sunload sensor
5) A/C switch relay
6) A/C switch
7) Fan switch
8) Blower motor
9) Resistance
10) HI, MH, ML and LO relays
System operation
Blower fan speed is automatically controlled so that the in-vehicle temperature is maintained to the set tem-
perature.
The temperature set by the PTC (Potentio Temperature Control) and the temperature detected by the in-
vehicle sensor and ambient sensor are compensated by the sunload sensor signal. The auto amplifier then
determines fan speed from the ON-OFF operation of the A/C switch. The fan speed decision by the auto
amplifier activates the fan relay and the blower fan motor rotates. When the A/C switch is ON, fan speed is
activated in 4 steps, HI, MH, ML, and LO. When the A/C switch is OFF, fan speed is activated in 3 steps,
MH, ML, and LO.
KHA130 Auto amplifier
In-vehicle
sensor
Ambient
sensor
Sunload
sensor
A/C switchConstant voltage
transformation
Air mix door posi-
tion arithmetic cir-
cuit
Sunload compen-
sationA/C operation
signal detection
Air flow volume
arithmetic circuitHI relay
MH
relay
ML
relayBlower
motor
Resistor
LO relay
Fan switch
(AUTO)
SYSTEM DESCRIPTIONAUTO
Control System Output Components (Cont'd)
HA-95

Signals from each sensor, PTC, A/C switch etc. are sent to the
air flow volume arithmetic circuit in the auto amplifier. Air flow
volume is determined by this circuit.
(1) When the air flow volume is set to ML
The air flow volume arithmetic circuit gives current to Tr
p3,
which turns the ML relay on. Thus, the blower motor rotates
in the ML condition.
SHA573CC
SHA574CA
Air flows
volume
arithmetic
circuitHI
relay
MH relay
ML relayBlower
motor
Resistor
Fan switch
(AUTO)
A/C (LO) relay
SYSTEM DESCRIPTIONAUTO
Control System Output Components (Cont'd)
HA-96

STARTING FAN SPEED CONTROL
The starting fan control system is so designed to prevent excess cold air from being expelled after the engine
is started when the engine coolant temperature is low.
The component parts related to this system are the water temperature sensor microswitch, HI, MH, ML and
LO relays, blower motor, resistance and auto amplifier.
When the fan switch is set to AUTO, the mode is selected either B/L, FOOT or FOOT/DEF and the engine
coolant temperature is below 56ÉC (133ÉF), the speed of the blower motor is fixed in the LO position.
LO, ML, MH AND HI RELAYS
The LO and ML relays are located on the auto amplifier bracket,
and the MH and HI relays are installed on the back side of the
audio unit. Each fan relay operates according to the air flow vol-
ume determined by the auto amplifier. The blower motor then
operates accordingly.
SHA188DA
Blower speed
1.0
0 (32) 50 (122) ÉC (ÉF)
Auto amp.
.Constant voltage
transformation
Sensor voltage
.Air mix door
position arithmetic
circuit
Air flow volume
arithmetic cir-
cuit
Mode switch
Water temperature meter
Thermal
transmitterFan switch (AUTO)LO relay ML relay MH relay HI relay
.Blower motor
Resistor
NHA304
.LO relay
.ML relay.HI relay
.MH relay
SYSTEM DESCRIPTIONAUTO
Control System Output Components (Cont'd)
HA-98

Checking Refrigerant Leaks
PRELIMINARY CHECK
Perform a visual inspection of all refrigeration parts, fittings,
hoses, and components for signs of A/C lubricant leakage, dam-
age and corrosion.
PRECAUTIONS FOR HANDLING LEAK DETECTOR
When performing a refrigerant leak check, use an A/C leak
detector or equivalent. Ensure that the instrument is calibrated
and set properly per the operating instructions.
The leak detector is a delicate device. In order to use the leak
detector properly, read the operating instructions and perform
any specified maintenance.
Other gases in the work area or substances on the A/C
components, for example, anti-freeze, windshield washer
fluid, solvents and cleaners, may falsely trigger the leak
detector. Make sure the surfaces to be checked are clean.
Do not allow the sensor tip of the detector to come into
contact with any substance. This can also cause false read-
ings and may damage the detector.
1. Position probe approximately 5 mm (3/16 in) away from point
to be checked.
2. When testing, circle each fitting completely with probe.
SHA705EB A/C leak
detector
SHA707E
SHA706E
SERVICE PROCEDURESAUTO
HA-106

A
AAC/V - Wiring diagram....EC-QG-276, EC-SR-265
ABS (anti-lock brake system).........................BR-50
A/C control linkage adjustment (manual
A/C) .............................................................HA-82
A/C control operation (auto A/C) ....................HA-19
A/C diagnostic work flow (auto A/C) ..............HA-26
A/C performance chart ...................................HA-35
A/C performance test diagnoses....................HA-33
A/C relay.........................................................HA-78
A/C service data specification ......................HA-118
A/C switch ......................................................HA-78
A/C symptom chart (auto A/C) .......................HA-28
A/C trouble diagnoses (auto A/C) ..................HA-26
Accelerator control system ...............................FE-3
Accelerator position sensor ...................EC-CD-108
Accelerator position switch ....................EC-CD-108
Accelerator wire adjustment .............................FE-4
A/CCUT - Wiring diagram ......................EC-CD-127
Air bag disposal..............................................RS-27
Air bag precautions ...........................................GI-3
Air bleeding for brake system ..........................BR-8
Air cleaner filter replacement ............MA-23, 34, 44
Air conditioner cut
control .....EC-QG-24, EC-SR-26, EC-CD-20, 126
Air flow meter - See Mass air flow
sensor ............................EC-QG-110, EC-SR-120
Air mix. door motor.........................................HA-92
Alternator ..................................................EL-53, 56
Ambient sensor ..............................................HA-86
Antenna .........................................................EL-229
Anti-lock brake system - See ABS .................BR-50
APS - Wiring diagram ............................EC-CD-109
A/T - Wiring diagram - AT - FTS .....................AT-56
A/T - Wiring diagram - AT - MAIN ...................AT-45
A/T - Wiring diagram - AT - PNP/SW..............AT-50
A/T - Wiring diagram - AT - VSS A/T ..............AT-64
A/T diagnosis communication line .........EC-SR-295
A/T fluid temperature sensor...........................AT-54
A/T trouble diagnoses ...............................AT-29, 30
A/T Wiring diagram - AT - ENG SS ................AT-67
A/T Wiring diagram AT - LPSV .......................AT-76
A/T Wiring diagram AT - TCV .........................AT-71
A/T Wiring diagram AT - TPS..........................AT-81
ATDIAG - Wiring diagram ......................EC-SR-296
Audio .............................................................EL-216
AUDIO - Wiring diagram ...............................EL-219
Audio and A/C control removal and
installation - See Instrument panel .............BT-15
Auto air conditioner - Wiring diagram ............HA-42
Automatic amplifier .........................................HA-87
Automatic transaxle number............................GI-44
Automatic transmission fluid
replacement..........................................MA-49, 50
Auxiliary air control (AAC)
valve ..............................EC-QG-274, EC-SR-263BBack door opener - See Back door ............BT-9, 11
Back door trim.................................................BT-30
Back door window ....................................BT-35, 56
Back-up lamp ................................................EL-107
BACK/L - Wiring diagram..............................EL-107
Ball joint front axle ....................................FA-32, 33
Base idle air volume
initialiging ...........................EC-QG-33, EC-SR-46
Basic inspection ....................EC-QG-72, EC-SR-84
Battery .............................................................EL-29
Body alignment ...............................................BT-60
Brake booster .................................................BR-18
Brake control valve (Proportioning
valve)...........................................................BR-11
Brake fluid change ...........................................BR-7
Brake fluid level .............................................MA-51
Brake fluid level and line check .......................BR-7
Brake hydraulic line ..........................................BR-9
Brake inspection ............................................MA-51
Brake lining wear temporary checking ..........MA-51
Brake pedal ....................................................BR-13
Bulb specifications ........................................EL-137
Bumper, front ....................................................BT-5
Bumper, rear .......................................BT-5, 7, 9, 11
BUZZER - Wiring diagram ............................EL-181
C
Camshaft inspection ...............EM-35, 91, 138, 147,
183, 192, 196
Camshaft position sensor
(CMPS) ..........................EC-QG-238, EC-SR-239
Camshaft position sensor (PHASE) ......EC-QG-238
Canister-See EVAP
canister ..............................EC-QG-25, EC-SR-27
CHARGE - Wiring diagram .............................EL-53
Charging system .............................................EL-53
Chassis and body maintenance ....................MA-48
CHIME - Wiring diagram ...............................EL-181
Cigarette lighter.............................................EL-203
Circuit breaker.................................................EL-22
CKPS - Wiring diagram....EC-QG-234, EC-SR-236,
292, EC-CD-115
Clock .............................................................EL-203
Closed throttle position switch ...............EC-SR-271
Clutch cover ....................................................CL-13
Clutch damper ................................................CL-10
Clutch disc ......................................................CL-13
Clutch fluid level.............................................MA-48
Clutch master cylinder ......................................CL-8
Clutch operating cylinder ..................................CL-9
Clutch release mechanism..............................CL-11
CMPS - Wiring diagram ....EC-QG-240, EC-SR-242
Coil spring (rear) .............................................RA-11
Collision diagnosis..........................................RS-57
Combination meter........................................EL-138
ALPHABETICAL INDEX
IDX-2