Page 511 of 4449
ATC-82
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
1. CHECK POWER SUPPLY FOR BLOWER MOTOR
1. Disconnect blower motor connector.
2. Turn ignition switch ON.
3. Check voltage between blower motor harness connector M78
terminal 1 (L/W) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 15A fuses [Nos. 10 and
11, located in the fuse block (J/B)]. Refer to PG-83,
"FUSE BLOCK - JUNCTION BOX (J/B)" .
If OK, check for open circuit in wiring harness. Repair or replace if necessary.
If NG, replace fuse and check wiring harness for short circuit. Repair or replace if necessary.
2. CHECK BLOWER MOTOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between blower motor harness connector M78
terminal 3 (B) and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK CIRCUIT CONTINUITY BETWEEN BLOWER MOTOR AND UNIFIED METER AND A/C AMP.
1. Disconnect unified meter and A/C amp. connector.
2. Check continuity between blower motor harness connector M78
terminal 2 (G) and unified meter and A/C amp. harness connec-
tor M57 terminal 53 (G).
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK UNIFIED METER AND A/C AMP. OUTPUT SIGNAL
1. Reconnect blower motor connector and unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Vary the fan speed between Lo and Hi and confirm the duty
ratios between blower motor harness connector M78 terminal 21 – Ground : Battery voltage
RJIA1997E
3 – Ground : Continuity should exist.
RJIA1998E
2 – 53 : Continuity should exist.
RJIA1999E
RJIA2000E
Page 512 of 4449
TROUBLE DIAGNOSIS
ATC-83
C
D
E
F
G
H
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K
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MA
B
AT C
Revision: 2004 November 2004 FX35/FX45
(G) and ground using an oscilloscope. Usual No. 2 terminal drive signal duty ratios are shown in the table
below.
OK or NG
OK >> GO TO 5.
NG >> Replace unified meter and A/C amp.
5. CHECK BLOWER MOTOR DRIVE SIGNAL
If the fan air flow does not change, usual No. 2 (G) terminal drive signal duty ratios are shown in the table
above.
OK or NG
OK >> Replace blower motor.
NG >> INSPECTION END
COMPONENT INSPECTION
Blower Motor
Confirm smooth rotation of the blower motor.
Ensure that there are no foreign particles inside the blower unit.
RJIA2001E
RJIA0905E
Page 516 of 4449
TROUBLE DIAGNOSIS
ATC-87
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D
E
F
G
H
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K
L
MA
B
AT C
Revision: 2004 November 2004 FX35/FX45
5. CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal. Refer to AT C - 4 0 , "
CONSULT-II" .
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
6. CHECK CIRCUIT CONTINUITY BETWEEN BCM 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
27 (R/Y) and unified meter and A/C amp. harness connector
M57 terminal 42 (R/Y).
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 (R/Y) and ground.
OK or NG
OK >> GO TO 8.
NG-1 >> If the voltage is approx. 5V when A/C switch is ON: Replace unified meter and A/C amp.
NG-2 >> If the voltage is approx. 0V when A/C switch is OFF: Replace BCM.A/C SW ON : AIR COND SW ON
A/C SW OFF : AIR COND SW OFF
R J I A 1111 E
27 – 42 : Continuity should exist.
RJIA2006E
Terminals
Condition Voltage (+)
(−) Unified meter
and A/C amp.
connectorTerminal No.
(wire color)
M57 42 (R/Y) GroundA/C switch: ON Approx. 0V
A/C switch: OFF Approx. 5V
RJIA2007E
Page 517 of 4449
ATC-88
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
8. CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start the engine.
2. Check voltage of refrigerant pressure sensor. Refer to EC-125, "
CONSULT-II Reference Value in Data
Monitor" (VQ35DE) or EC-775, "CONSULT-II Reference Value in Data Monitor" (VK45DE).
WITHOUT CONSULT-II
1. Start the engine.
2. Check voltage between ECM harness connector F101 terminal
70 (L/R) and ground.
OK or NG
OK >>WITH CONSULT-II
GO TO 9.
WITHOUT CONSULT-II
GO TO 10.
NG >> Refer to EC-609, "
REFRIGERANT PRESSURE SENSOR" (VQ35DE) or EC-1287, "REFRIGER-
ANT PRESSURE SENSOR" (VK45DE).
9. CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to AT C - 4 0 , "
CONSULT-II" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10. CHECK CIRCUIT CONTINUITY BETWEEN BCM 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 (BR/Y) and unified meter and A/C amp. harness connector
M57 terminal 57 (BR/Y).
OK or NG
OK >> GO TO 11.
NG >> Repair harness or connector.
Te r m i n a l s
Condition Voltage (+)
(−)
ECM con-
nectorTerminal No.
(wire color)
F101 70 (L/R) Ground A/C switch: ON Approx. 1 - 4V
PBIB1188E
FAN SW ON :FAN ON SIG ON
FAN SW OFF :FAN ON SIG OFF
R J I A 1111 E
28 – 57 : Continuity should exist.
RJIA2009E
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TROUBLE DIAGNOSIS
ATC-89
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AT C
Revision: 2004 November 2004 FX35/FX45
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 (BR/Y) and ground.
OK or NG
OK >> GO TO 12.
NG-1 >> If the voltage is approx. 5V when blower motor is ON: Replace unified meter and A/C amp.
NG-2 >> If the voltage is approx. 0V when blower motor is OFF: Replace BCM. Refer to BCS-15, "
Removal
and Installation of BCM" .
12. CHECK CAN COMMUNICATION
Check CAN communication. Refer to BCS-14, "
CAN Communication Inspection Using CONSULT-II (Self-
Diagnosis)" .
BCM – ECM
ECM – IPDM E/R
ECM – Unified meter and A/C amp.
OK or NG
OK >> INSPECTION END
NG >> Repair or replace malfunctioning part(s).
Terminals
Condition Voltage (+)
(-) Unified meter
and A/C amp.
connectorTerminal No.
(wire color)
M57 57 (BR/Y) GroundA/C switch: ON
(Blower motor
operates)Approx. 0V
OFF switch: ON
(A/C system:
OFF)Approx. 5V
RJIA2010E
Page 527 of 4449
ATC-98
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
DIAGNOSTIC PROCEDURE FOR INSUFFICIENT COOLING
SYMPTOM: Insufficient cooling
1. CHECK POWER SUPPLY FOR ECV (ELECTRONIC CONTROL VALVE)
1. Disconnect compressor (ECV) connector.
2. Turn ignition switch ON.
3. Check voltage between compressor harness connector F6 ter-
minal 2 (G) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 10A fuse [No. 12,
located in the fuse block (J/B)]. Refer to PG-83, "
FUSE
BLOCK - JUNCTION BOX (J/B)" .
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.
Air conditioning system
does not function and does
not cyclically cool the com-
partment air.
The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.Refrigerant does not dis-
charge cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refriger-
ant.
Drain water from refrigerant
or replace refrigerant.
Replace liquid tank.
AC354A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side becomes nega-
tive.
Liquid tank or front/rear side of
expansion valve′s pipe is
frosted or dewed.High-pressure side is closed
and refrigerant does not flow.
↓
Expansion valve or liquid tank
is frosted.Leave the system at rest until
no frost is present. Start it
again to check whether or not
the malfunction 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 refrig-
erant.
If due to foreign particles,
remove expansion valve
and remove the particles
with dry and compressed air
(not shop air).
If either of the above meth-
ods cannot correct the mal-
function, replace expansion
valve.
Replace liquid tank.
Check lubricant for contami-
nation.
AC362A
2 – ground : Battery voltage
RJIA2294E
Page 531 of 4449
ATC-102
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Self-diagnosisAJS00152
SYMPTOM: Self-diagnosis cannot be performed.
INSPECTION FLOW
*1 Compressor Clutch, ATC-143,
"REMOVAL" .*2 Compressor Clutch, ATC-145, "INSTALLATION" .*3AT C - 2 7 , "
Maintenance of Lubricant
Quantity in Compressor".
*4ATC-61, "
Operational Check".*5EM-15, "Checking Drive Belts"
(VQ35DE) or EM-169, "
Checking
Drive Belts" (VK45DE).
*1ATC-63, "
Power Supply and Ground
Circuit for Auto Amp.".*2ATC-104, "
Ambient Sensor Circuit".*3ATC-107, "In-vehicle Sensor Circuit".
*4ATC-110, "
Sunload Sensor Circuit".*5ATC-113, "Intake Sensor Circuit".*6AT C - 7 5 , "Air Mix Door Motor PBR
Circuit".
*7ATC-61, "
Operational Check".*8ATC-42, "SYMPTOM TABLE".
RJIA2014E
Page 532 of 4449
TROUBLE DIAGNOSIS
ATC-103
C
D
E
F
G
H
I
K
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MA
B
AT C
Revision: 2004 November 2004 FX35/FX45
Memory FunctionAJS00153
SYMPTOM: Memory function does not operate.
INSPECTION FLOW
*1AT C - 6 3 , "Power Supply and Ground
Circuit for Auto Amp.".*2ATC-61, "
Operational Check".*3AT C - 5 4 , "FUNCTION CONFIRMA-
TION PROCEDURE".
RJIA2015E
