ATC-60
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Operational CheckNJS000E1
The purpose of the operational check is to check if the individual system operates properly.
CHECKING MEMORY FUNCTION
1. Press the temperature control (UP) switch (driver side) until 32°C (90 °F) is displayed.
2. Press OFF switch.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous temperature.
7. Press OFF switch.
If NG, go to trouble diagnosis procedure for ATC-102, "
Memory Function" .
If OK, continue the check.
CHECKING BLOWER
1. Press fan (UP:+) switch. Blower should operate on low speed. The fan symbol should have one blade lit.
2. Press fan (UP:+) switch again, and continue checking blower speed and fan symbol until all speeds are checked.
3. Leave blower on max. speed.
If NG, go to trouble diagnosis procedure for AT C - 7 7 , "
Blower Motor Circuit" .
If OK, continue the check.
CHECKING DISCHARGE AIR
1. Press MODE switch and DEF switch.
2. Each position indicator should change shape.
3. Confirm that discharge air comes out according to the air distri- bution table. Refer to AT C - 3 7 , "
Discharge Air Flow" .
If NG, go to trouble diagnosis procedure for AT C - 6 8 , "
Mode Door
Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at FRE when the D/F or DEF
is selected.
CHECKING INTAKE AIR
1. Press intake switch. Recirculation indicator should illuminate.
2. Press intake switch again. Fresh indicator should illuminate.
3. Listen for intake door position change. (Slight change of blower sound can be heard.)
If NG, go to trouble diagnosis procedure for AT C - 7 4 , "
Intake Door Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual inspection) and intake door position is at FRE
when the D/F or DEF is selected.
CHECKING TEMPERATURE DECREASE
1. Press temperature control (DOWN) switch (driver side) until 18 °C (60 °F) is displayed.
2. Check for cold air at discharge air outlets.
If NG, go to trouble diagnosis procedure for AT C - 9 0 , "
Insufficient Cooling" .
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Press temperature control (UP) switch (driver side) until 32 °C (90 °F) is displayed.
Conditions : Engine running at normal operating temperature
SJIA0302E
TROUBLE DIAGNOSIS ATC-87
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AT C
Revision: 2006 July 2007 FX35/FX45
8. CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start the engine.
2. Check voltage of refrigerant pressure sensor. Refer to EC-132, "
CONSULT-II Reference Value in Data
Monitor" (VQ35DE) or EC-796, "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 and ground.
OK or NG
OK >>WITH CONSULT-II: GO TO 9.
WITHOUT CONSULT-II: GO TO 10.
NG >> Refer to EC-663, "
REFRIGERANT PRESSURE SENSOR" (VQ35DE) or EC-1345, "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 Function
(BCM)" .
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 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.
Terminals
Condition Voltage
(+)
( − )
ECM
connec-
tor Terminal
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
R J I A 1111 E
28 – 57 : Continuity should exist.
RJIA2009E
TROUBLE DIAGNOSIS ATC-95
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AT C
Revision: 2006 July 2007 FX35/FX45
TROUBLE DIAGNOSIS FOR UNUSUAL PRESSURE
Whenever system’s high and/or low side pressure(s) is/are unusual, diagnose using a manifold gauge. The
marker above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the
standard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air tempera-
ture-to-operating pressure table).
Both High- and Low-pressure Sides are Too High
High-pressure Side is Too High and Low-pressure Side is Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too high. The pressure returns to nor-
mal soon after water is
splashed on condenser. Excessive refrigerant charge
in refrigeration cycle. Reduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is
insufficient. Insufficient condenser cooling
performance.
↓
1. Condenser fins are clogged.
2. Improper fan rotation of cooling fan.
Clean condenser.
Check and repair cooling fan
as necessary.
Low-pressure pipe is not
cold.
When compressor is
stopped high-pressure
value quickly drops by
approximately 196 kPa (2
kg/cm
2 , 28 psi). It then
decreases gradually there-
after. Poor heat exchange in con-
denser
(After compressor operation
stops, high-pressure
decreases too slowly.).
↓
Air in refrigeration cycle. Evacuate repeatedly and
recharge system.
Engine tends to overheat. Engine cooling systems mal-
function. Check and repair each engine
cooling system.
An area of the low-pres-
sure pipe is colder than
areas near the evaporator
outlet.
Low-pressure pipe is
sometimes covered with
frost.
Excessive liquid refrigerant
on low-pressure side.
Excessive refrigerant dis-
charge flow.
Expansion valve is open a
little compared with the
specification.
↓
Improper expansion valve
adjustment. Replace expansion valve.
AC359A
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too high and
low-pressure side is too low.
Upper side of condenser and
high-pressure side are hot,
however, liquid tank is not so
hot. High-pressure tube or parts
located between compressor
and condenser are clogged or
crushed.
Check and repair or replace
malfunctioning parts.
Check lubricant for contami-
nation.
AC360A
TROUBLE DIAGNOSIS ATC-99
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AT C
Revision: 2006 July 2007 FX35/FX45
Insufficient HeatingNJS000EB
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-60, "Operational Check"*2ATC-71, "Air Mix Door Motor Circuit"*3AT C - 5 3 , "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 4 to
6.
*4 ATC-53, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13. *5
ATC-64, "
LAN System Circuit"*6AT C - 7 7 , "Blower Motor Circuit"
*7 EC-209, "DTC P0117, P0118 ECT
SENSOR" (VQ35DE) or EC-880,
"DTC P0117, P0118 ECT SEN-
SOR" (VK45DE) *8
CO-11, "
Changing Engine Coolant"
(VQ35DE) or CO-38, "
Changing
Engine Coolant" (VK45DE) *9
CO-15, "
Checking Radiator Cap"
(VQ35DE) or CO-43, "
Checking
Radiator Cap" (VK45DE)
SJIA1593E
TROUBLE DIAGNOSIS ATC-103
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AT C
Revision: 2006 July 2007 FX35/FX45
Ambient Sensor CircuitNJS000EF
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor is attached on the hood lock stay. It detects
ambient temperature and converts it into a resistance value which is
then input into the unified meter and A/C amp.
AMBIENT TEMPERATURE INPUT PROCESS
The unified meter and A/C amp. includes a processing circuit for the ambient sensor input. However, when the
temperature detected by the ambient sensor increases quickly, the processing circuit retards the unified meter
and A/C amp. function. It only allows the unified meter and A/C amp. to recognize an ambient temperature
increase of 0.33 °C (0.6 °F) per 100 seconds.
As an example, consider stopping for a few minutes after high speed driving. Although the actual ambient tem-
perature 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.
DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR
SYMPTOM: Ambient sensor circuit is open or shorted. (21 or −21 is
indicated on unified meter and A/C amp. as a result of performing
self-diagnosis STEP-2.)
1. CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND
1. Disconnect ambient sensor connector.
2. Turn ignition switch ON.
3. Check voltage between ambient sensor harness connector E34 terminal 1 and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA2016E
RJIA1461E
1 – Ground : Approx. 5 V
RJIA2017E
HEATER & COOLING UNIT ASSEMBLY ATC-127
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AT C
Revision: 2006 July 2007 FX35/FX45
Insert piping securely until a click is heard.
After piping connection is completed, pull male-side piping by hand to make sure that connection
does not come loose.
When recharging refrigerant, check for leaks.
NOTE:
When filling radiator with coolant, refer to CO-11, "Changing Engine Coolant" (VQ35DE) or CO-38,
"Changing Engine Coolant" (VK45DE).
Recharge the refrigerant.
Heater & cooling unit assembly mounting bolt : 6.8 N·m (0.69 kg-m, 60 in-lb)
Steering member mounting nut and bolt : 12 N·m (1.2 kg-m, 9 fl-lb)
Steering column mounting nut and bolt : 16.7 N·m (1.7 kg-m, 12 fl-lb)
ATC-148
REFRIGERANT LINES
Revision: 2006 July 2007 FX35/FX45
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:
Replace O-rings of high-pressure flexible hose with new ones, and then apply compressor oil to it
when installing it.
Female-side piping connection is thin and easy to deform. Slowly insert the male-side piping
straight in axial direction.
Insert piping securely until a click is heard.
After piping connection is completed, pull male-side piping by hand to make sure that connection
does not come loose.
When recharging refrigerant, check for leaks.
Removal and Installation of Low-pressure Pipe 1 (Engine Compartment)NJS000F6
REMOVAL
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Remove cowl top cover. Refer to EI-23, "
COWL TOP" .
3. Remove low-pressure pipe 1 bracket and low-pressure flexible hose bracket mounting bolts.
4. Disconnect one-touch joints.
a. Set a disconnector (SST: 9253089916) on A/C piping.
b. Slide a disconnector toward vehicle front until it clicks.
c. Slide A/C piping toward vehicle front and disconnect it.
RJIA2067E
High-pressure flexible hose bracket mounting bolt
: 5.5 N·m (0.56 kg-m, 49 in-lb)
RJIA2068E
RJIA2069E
REFRIGERANT LINES ATC-149
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AT C
Revision: 2006 July 2007 FX35/FX45
5. Remove low-pressure pipe 1.
CAUTION:
Cap or wrap the joint of low-pressure pipe 1 and 2 with suit-
able material such as vinyl tape to avoid the entry of air.
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:
Replace O-rings of low-pressure pipe 1 with new ones, and then apply compressor oil to it when
installing it.
Female-side piping connection is thin and easy to deform. Slowly insert the male-side piping
straight in axial direction.
Insert piping securely until a click is heard.
After piping connection is completed, pull male-side piping by hand to make sure that connection
does not come loose.
When recharging refrigerant, check for leaks.
Removal and Installation of High-pressure Pipe 1 and 2 (Engine Compartment)NJS000F7
REMOVAL
1. Remove low-pressure pipe 1. Refer to ATC-148, "Removal and Installation of Low-pressure Pipe 1
(Engine Compartment)" .
2. Remove high-pressure flexible hose and low-pressure flexible hose. Refer to ATC-147, "
Removal and
Installation of High-pressure Flexible Hose" and ATC-146, "Removal and Installation of Low-pressure
Flexible Hose" .
3. Remove high-pressure pipe 1 and 2 from clips.
4. Disconnect one-touch joint between condenser and high-pres- sure pipe 1.
a. Set a disconnector (SST: 9253089908) on A/C piping.
b. Slide a disconnector upward until it clicks.
c. Slide A/C piping upward and disconnect it. CAUTION:
Cap or wrap the joint of condenser and high-pressure pipe
1 with suitable material such as vinyl tape to avoid the entry
of air.
RJIA2037E
Low-pressure pipe 1 bracket and low-pressure flexible hose bracket mounting bolts
: 5.5 N·m (0.56 kg-m, 49 in-lb)
RJIA2070E
RJIA2071E