2006 NISSAN PATROL Service Manual

DIAGNOSTIC PROCEDURE
SYMPTOM: Magnet clutch does not engage when A/C switch
and fan switch are ON.
CHECK POWER SUPPLY FOR COM-
PRESSOR.
Disconnect compressor harness connector.
Do approx. 12 volts exist between compres-
sor harness terminal No.j
1and body
ground?
No
cYe s
Check magnet clutch coil.
NG
Replace magnet clutch.
Refer to HA-123.
Disconnect A/C relay.
Note
CHECK CIRCUIT CONTINUITY
BETWEEN A/C RELAY HARNESS TERMI-
NAL NO.j
7AND COMPRESSOR HAR-
NESS TERMINAL NO.j1.
Continuity should exist.
If OK, check harness for short.
OK
CHECK POWER SUPPLY FOR A/C
RELAY.
Disconnect A/C relay.
Do approx. 12 volts exist between A/C
relay harness terminal Nos.j
1,j6and
body ground?
Ye s
cNo
CHECK POWER SUPPLY
CIRCUIT AND 10A (No.
) FUSES AT FUSE
BLOCK.
Refer to EL section (``Wiring
Diagram'', ``POWER SUP-
PLY ROUTING'').
CHECK A/C RELAY AFTER DISCON-
NECTING IT.
Refer to HA-47.
OK
cNG
Replace A/C relay.
jA(Go to next page.)
Note:
If the result is NG or No after checking circuit continuity, repair harness or
connector.
RHA747FE
RHA607GA
RHA608G
.
.
.
.
.
.
TROUBLE DIAGNOSESMANUAL
Magnet Clutch (Cont'd)
HA-44

jA
Reconnect A/C relay.
CHECK COIL SIDE CIRCUIT OF A/C
RELAY.
Do approx. 12 volts exist between ECM
(ECCS control module) harness terminal
No.j
9and body ground?
Ye s
cNo
Disconnect A/C relay.
Disconnect ECM (ECCS
control module) harness
connector.
Note
CHECK CIRCUIT CONTI-
NUITY BETWEEN A/C
RELAY HARNESS TERMI-
NAL NO.j
2AND ECM
(ECCS CONTROL MOD-
ULE) HARNESS TERMI-
NAL NO.j
9.
Continuity should exist.
If OK, check harness for
short.
CHECK VOLTAGE FOR ECM (ECCS con-
trol module).
Do approx. 12 volts exist between ECM
(ECCS control module) harness terminal
No.j
46and body ground?
Ye s
cNo
CHECK ECM (ECCS con-
trol module). Refer to EC
section.
Disconnect ECM (ECCS control module)
harness connector.
Disconnect dual-pressure switch harness
connector.
Note
CHECK CIRCUIT CONTINUITY
BETWEEN ECM (ECCS CONTROL MOD-
ULE) HARNESS TERMINAL NO.j
46AND
DUAL-PRESSURE SWITCH HARNESS
TERMINAL NO.j
2.
Continuity should exist.
If OK, check harness for short.
OK
CHECK DUAL-PRESSURE SWITCH.
Refer to HA-47.
OK
cNG
Check refrigerant charge
amount.
OK
Disconnect thermo control amp. switch
harness connector.
Replace dual-pressure
switch.
Note
CHECK CIRCUIT CONTINUITY
BETWEEN DUAL-PRESSURE SWITCH
HARNESS TERMINAL NO.j
1AND
THERMO CONTROL AMP. HARNESS
TERMINAL NO.j
3.
Continuity should exist.
If OK, check harness for short.
OK
j
B
Note:
If the result is NG or No after checking circuit continuity, repair harness or
connector.
RHA749FA
RHA609G
RHA610G
RHA611G
RHA612G
.
.
.
.
.
.
.
..
.
.
TROUBLE DIAGNOSESMANUAL
Magnet Clutch (Cont'd)
HA-45

jB
CHECK POWER SUPPLY FOR THERMO
CONTROL AMP.
Disconnect thermo control amp. harness
connector.
Do approx. 12 volts exist between thermo
control amp. harness terminal No.j
1and
body ground?
Ye s
cNo
CHECK POWER SUPPLY
CIRCUIT AND 10A FUSES
AT FUSE BLOCK.
Refer to EL section (``Wiring
Diagram'', ``POWER SUP-
PLY ROUTING'').
CHECK BODY GROUND CIRCUIT FOR
THERMO CONTROL AMP.
Turn A/C switch ON.
Does continuity exist between thermo
control amp. harness terminalj
2and
body ground?
Ye s
cNo
CHECK THERMO CON-
TROL AMP.
Refer to HA-47.
Disconnect A/C switch harness connector.
CHECK A/C SWITCH.
Refer to HA-47.
OK
cNG
Replace A/C switch.
Disconnect fan switch harness connector.
Note
CHECK CIRCUIT CONTINUITY
BETWEEN A/C SWITCH HARNESS
TERMINAL NO.j
2AND FAN SWITCH
HARNESS TERMINAL NO.j
6.
Continuity should exist.
If OK, check harness for short.
OK
Note
CHECK BODY GROUND CIRCUIT FOR
FAN SWITCH.
Does continuity exist between fan switch
harness terminal No.j
5and body
ground?
Ye s
CHECK FAN SWITCH.
Refer to HA-31.
cNG
Replace fan switch.
Note:
If the result is NG or No after checking circuit continuity, repair harness or
connector.
RHA615G
RHA616G
RHA613G
RHA614G
.
.
.
.
.
.
.
.
TROUBLE DIAGNOSESMANUAL
Magnet Clutch (Cont'd)
HA-46

ELECTRICAL COMPONENTS INSPECTION
A/C switch
Check continuity between terminals at each switch position.
Switch condition Terminal No.
Continuity
A/C (+) (þ)
ON
j
2j1Ye s
OFF No
A/C relay
Check continuity between terminalsj3andj5,j6andj7.
Condition Continuity
12V direct current supply between
terminalsj
1andj2Ye s
No current supply No
Dual-pressure switch
ON
kPa (bar, kg/cm2, psi)OFF
kPa (bar, kg/cm2, psi)
Low-pressure sideIncreasing to 157 - 216
(1.57 - 2.16, 1.6 - 2.2,
23 - 31)Decreasing to 157 - 196
(1.57 - 1.96, 1.6 - 2.0,
23 - 28)
High-pressure sideDecreasing to 1,863 -
2,256 (18.6 - 22.6,
19 - 23, 270 - 327)Increasing to 2,452 -
2,844 (24.5 - 28.4,
25 - 29, 356 - 412)
Thermo control amp.
Evaporator outlet air
temperature
ÉC (ÉF)Thermo amp. operation Tester
Decreasing to 0.1 - 0.9
(32 - 34)Turn OFF Approx. 12V
Increasing to 2.5 - 3.5
(37 - 38)Turn ON Approx. 0V
RHA626G
SEC202B
RHA628G
RHA736G
TROUBLE DIAGNOSESMANUAL
Magnet Clutch (Cont'd)
HA-47

Noise
TROUBLE DIAGNOSIS PROCEDURE FOR NOISE
SYMPTOM:
+Noise
Inspection ¯ow
*1: HA-123 *2: HA-125 *3: HA-120
SHA909E
TROUBLE DIAGNOSESMANUAL
HA-48

Introduction
AIR CONDITIONER LAN SYSTEM OVERVIEW CONTROL SYSTEM
The LAN system consists of auto amp., air mix door motor and mode door motor.
A con®guration of these components is shown in the diagram below.
Features
SYSTEM CONSTRUCTION (LAN)
A small network is constructed between the auto ampli®er, air mix door motor and mode door motor. The auto
ampli®er and motors are connected by data transmission lines and motor power supply lines. The LAN net-
work is built through the ground circuits of the two motors.
Addresses, motor opening angle signals, motor stop signals and error checking messages are all transmitted
through the data transmission lines connecting the auto ampli®er and two motors.
The following functions are contained in LCUs built into the air mix door motor and the mode door motor.
+Address
+Motor opening angle signals
+Data transmission
+Motor stop and drive decision
+Opening angle sensor (PBR function)
+Comparison
+Decision (Auto ampli®er indicated value and motor opening angle comparison)
RHA439G
RHA440GA
DESCRIPTIONAUTO
HA-49

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

Air mix door control (Automatic temperature control)
The air mix door is 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 based on temperature setting, ambient temperature, in-vehicle
temperature, intake temperature, amount of sunload and air mix door position.
With FAN switch set to ``AUTO'', the blower motor starts to gradually increase air ¯ow volume.
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from ¯ow-
ing.
Intake door control
The intake doors are automatically controlled by: The temperature setting, ambient temperature, in-vehicle
temperature, intake temperature, amount of sunload and ON-OFF operation of the compressor.
Outlet door control
The outlet door is automatically controlled by: The temperature setting, ambient temperature, in-vehicle
temperature, intake temperature and amount of sunload.
Magnet clutch control
The ECM (ECCS control module) controls compressor operation using input signals from the throttle position
sensor and auto ampli®er.
Self-diagnostic system
The self-diagnostic system is built into the auto ampli®er (LCU) to quickly locate the cause of problems.
RHA442G
DESCRIPTIONAUTO
Features (Cont'd)
HA-51