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ATC-72
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
3. Check continuity between BCM harness connector M3 terminal27 and unified meter and A/C amp. harness connector M57 ter-
minal 42.
OK or NG
OK >> GO TO 7.
NG >> Repair harness or connector.
7.CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (COMPRESSOR ON SIGNAL)
1. Reconnect BCM connector and unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Check voltage between unified meter and A/C amp. harness connector M57 terminal 42 and ground using an oscilloscope.
OK or NG
OK >> GO TO 8.
NG-1 >> If the voltage is approx. 5 V when A/C switch is ON: Replace unified meter and A/C amp.
NG-2 >> If the voltage is approx. 0 V w hen A/C switch is OFF: Replace BCM.
8.CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-III
1. Start the engine.
2. Check voltage of refrigerant pressure sensor in “Data monitor”. Refer to EC-127, "
CONSULT-III Reference
Value in Data Monitor Mode" (VQ35DE) or EC-705, "CONSULT-III Reference Value in Data Monitor
Mode" (VK45DE).
WITHOUT CONSULT-III
1. Start the engine. 27 – 42 : Continuity should exist.
RJIA2006E
RJIA2007E
Te r m i n a l s
Condition Voltage
(+)
(− )
Unified meter
and A/C amp.
connector Te r m i n a l
No.
M57 42 Ground A/C switch: ON
(Blower motor operates.)
Approx. 0 V
OFF switch: ON
(A/C system: OFF)
SJIA1423J
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TROUBLE DIAGNOSISATC-73
< SERVICE INFORMATION >
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2. Check voltage between ECM harness connector F101 terminal 70 and ground.
OK or NG
OK >> WITH CONSULT-III: GO TO 9. WITHOUT CONSULT-III: GO TO 10.
NG >> Refer to EC-581
(VQ35DE) or EC-1177 (VK45DE).
9.CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal in “Data monitor”. Refer to ATC-32, "
CONSULT-III Function".
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10.CHECK CIRCUIT CONTINUITY BETWEEN BC M AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect BCM connector and unified meter and A/C amp. connector.
3. Check continuity between BCM harness connector M3 terminal 28 and unified meter and A/C amp. harness connector M57 ter-
minal 57.
OK or NG
OK >> GO TO 11.
NG >> Repair harness or connector.
11 .CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (FAN ON SIGNAL)
1. Reconnect BCM connector and unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Check voltage between unified meter and A/C amp. harness connector M57 terminal 57 and ground using an oscilloscope.
Te r m i n a l s
Condition Voltage
(+)
(− )
ECM
connec- tor Te r m i n a l
No.
F101 70 Ground A/C switch: ON
(Blower motor operates.)Approx. 1.0 - 4.0
V
PBIB1188E
FAN SW ON : FAN ON SIG ON
FAN SW OFF : FAN ON SIG OFF
28 – 57 : Continuity should exist.
RJIA2009E
RJIA2010E
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ATC-74
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
OK or NG
OK >> GO TO 12.
NG-1 >> If the voltage is approx. 5 V when blower motor is ON: Replace unified meter and A/C amp.
NG-2 >> If the voltage is approx. 0 V when blower motor is OFF: Replace BCM.
12.CHECK CAN COMMUNICATION
Check CAN communication. Refer to BCS-13, "
U1000 CAN Communication Circuit".
BCM – ECM
ECM – IPDM E/R
ECM – Unified meter and A/C amp.
OK or NG
OK >> Replace ECM
NG >> Repair or replace malfunctioning part(s).
COMPONENT INSPECTION
Refrigerant Pressure Sensor
The refrigerant pressure sensor is attached to the condenser.
Make sure that the A/C refrigerant pressure and the sensor output
voltage are within the specified r ange as shown in the A/C operating
condition figure. Refer to EC-581
(VQ35DE) or EC-1177 (VK45DE).
Te r m i n a l s
Condition Voltage
(+)
(− )
Unified meter
and A/C amp.
connector Te r m i n a l N o .
M57 57 Ground A/C switch: ON
(Blower motor operates.)
Approx. 0 V
OFF switch: ON
(A/C system: OFF)
SJIA1474J
RJIA2011E
RJIA2954E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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TROUBLE DIAGNOSISATC-75
< SERVICE INFORMATION >
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Insufficient CoolingINFOID:0000000001328191
SYMPTOM: Insufficient cooling
INSPECTION FLOW
*1 AT C - 4 3 , "Self-Diagnosis Function",
see No. 4 to 6. *2
AT C - 5 9 , "Air Mix Door Motor Circuit"*3 "Test Reading"
*4 AT C - 4 3 , "
Self-Diagnosis Function"*5 AT C - 4 3 , "Self-Diagnosis Function",
see No. 13. *6
AT C - 5 4 , "LAN System Circuit"
*7AT C - 6 4 , "Blower Motor Circuit"*8 AT C - 6 9 , "Magnet Clutch Circuit"*9 "PERFORMANCE TEST DIAGNO-
SIS"
SJIA1592E
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TROUBLE DIAGNOSISATC-77
< SERVICE INFORMATION >
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PERFORMANCE CHART
Test Condition
Testing must be performed as follows:
*1 ATC-125, "Removal and Installation
of Compressor Clutch"
*2AT C - 6 4 , "Blower Motor Circuit"*3 EM-14, "Checking Drive Belts"
(VQ35DE) or EM-170, "
Checking
Drive Belts" (VK45DE)
SJIA1642E
Vehicle condition Indoors or in the shade (in a well-ventilated place)
Doors Closed
Door windows Open
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ATC-80
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too low. There is a big temperature
difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.
Liquid tank inlet and expan-
sion valve are frosted. Liquid tank inside is slightly
clogged.
Replace liquid tank.
Check lubricant for contami-
nation.
Temperature of expansion valve inlet is extremely low
as compared with areas
near liquid tank.
Expansion valve inlet is frosted.
Temperature difference oc- curs somewhere in high-
pressure side. High-pressure pipe located be-
tween liquid tank and expan-
sion valve is clogged.
Check and repair malfunc-
tioning parts.
Check lubricant for contami- nation.
Expansion valve and liquid
tank are warm or slightly cool
when touched. Low refrigerant charge.
↓
Leaking fittings or compo-
nents.
Check refrigerant for leaks.
Refer to
ATC-138, "
Checking
of Refrigerant Leaks".
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted. Expansion valve closes a little
compared with the specifica-
tion.
↓
1. Improper expansion
valve adjustment.
2. Malfunctioning expansion
valve.
3. Outlet and inlet may be clogged. Remove foreign particles by
using compressed air.
Replace expansion valve.
Check lubricant for contami-
nation.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet. Low-pressure pipe is clogged
or crushed. Check and repair malfunc-
tioning parts.
Check lubricant for contami- nation.
Air flow volume is not enough
or is too low. Evaporator is frozen. Check intake sensor circuit.
Refer to AT C - 9 4 , "
Intake
Sensor Circuit".
Replace compressor.
Repair evaporator fins.
Replace evaporator.
Refer to AT C - 6 4 , "
Blower
Motor Circuit".
AC353A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes be-
comes negative. Air conditioning system does
not function and does not cy-
clically 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 expan-
sion valve outlet and inlet.
↓
Water is mixed with refrigerant.
Drain water from refrigerant
or replace refrigerant.
Replace liquid tank.
AC354A
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TROUBLE DIAGNOSISATC-83
< SERVICE INFORMATION >
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NoiseINFOID:0000000001328193
SYMPTOM: Noise
INSPECTION FLOW
*1 AT C - 5 0 , "Operational Check"*2AT C - 5 9 , "Air Mix Door Motor Circuit"*3AT C - 4 3 , "Self-Diagnosis Function",
see No. 4 to 6.
*4 AT C - 4 3 , "
Self-Diagnosis Function",
see No. 13. *5
AT C - 5 4 , "LAN System Circuit"*6AT C - 6 4 , "Blower Motor Circuit"
*7 EC-193 (VQ35DE) or EC-779
(VK45DE) *8
CO-10, "Changing Engine Coolant"
(VQ35DE) or CO-37, "
Changing En-
gine Coolant" (VK45DE) *9
CO-14, "
Checking Radiator Cap"
(VQ35DE) or CO-42, "
Checking Ra-
diator Cap" (VK45DE)
SJIA1593E
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BLOWER UNITATC-103
< SERVICE INFORMATION >
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BLOWER UNIT
Removal and InstallationINFOID:0000000001328206
REMOVAL
1. Remove instrument passenger lower panel. Refer to IP-10.
2. Remove mounting nut, and then remove ECM with bracket attached.
3. Disconnect intake door motor connector and blower fan motor connector.
4. Remove harness clip from blower unit.
5. Remove mounting bolt and screws from blower unit. CAUTION:
Move blower unit rightward, and remove locating pin (1
part) and joint. Then remove blower unit downward.
6. Remove blower unit.
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:
Make sure locating pin (1 part) and joint are securely inserted.
RJIA2039E
RJIA0943E
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