2005 INFINITI QX4 check engine

ATC-4Revision: October 20052005 QX56 INSTALLATION ..................................................183
Removal and Installation for High-pressure Flexible
Hose .....................................................................183
REMOVAL .........................................................183
INSTALLATION ..................................................183
Removal and Installation for High-pressure Pipe . 183
REMOVAL .........................................................183
INSTALLATION ..................................................183
Removal and Installation for Low-pressure Pipe ..184
REMOVAL .........................................................184
INSTALLATION ..................................................184
Removal and Installation for Underfloor Rear A/C
Pipes .....................................................................184
REMOVAL .........................................................184
INSTALLATION ..................................................184
Removal and Installation for Rear A/C Pipes .......184
REMOVAL .........................................................184
INSTALLATION ..................................................184
Removal and Installation for Refrigerant Pressure
Sensor ..................................................................185
REMOVAL .........................................................185
INSTALLATION ..................................................185
Removal and Installation for Condenser ...............185
REMOVAL .........................................................185
INSTALLATION ..................................................185
Removal and Installation for Front Evaporator .....186REMOVAL .......................................................... 186
INSTALLATION .................................................. 187
Removal and Installation for Rear Evaporator ...... 187
REMOVAL .......................................................... 188
INSTALLATION .................................................. 188
Removal and Installation for Front Expansion Valve . 188
REMOVAL .......................................................... 188
INSTALLATION .................................................. 188
Removal and Installation for Rear Expansion Valve . 188
REMOVAL .......................................................... 188
INSTALLATION .................................................. 189
Checking for Refrigerant Leaks ............................ 189
Checking System for Leaks Using the Fluorescent
Dye Leak Detector ................................................ 189
Dye Injection ......................................................... 189
Electronic Refrigerant Leak Detector .................... 190
PRECAUTIONS FOR HANDLING LEAK
DETECTOR ....................................................... 190
CHECKING PROCEDURE ................................ 191
SERVICE DATA AND SPECIFICATIONS (SDS) .... 193
Service Data and Specifications (SDS) ................ 193
COMPRESSOR ................................................. 193
LUBRICANT ....................................................... 193
REFRIGERANT ................................................. 193
ENGINE IDLING SPEED ................................... 193
BELT TENSION ................................................. 193

PRECAUTIONS
ATC-11
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After connecting line, conduct leak test and make sure that there is no leakage from connections.
When the gas leaking point is found, disconnect that line and replace the O-ring. Then tighten con-
nections of seal seat to the specified torque.
Precautions for Servicing CompressorEJS003WV

Plug all openings to prevent moisture and foreign matter from entering.

When the compressor is removed, store it in the same position as it is when mounted on the car.

When replacing or repairing compressor, follow “Maintenance of Lubricant Quantity in Compres-
sor” exactly. Refer to ATC-22, "
Maintenance of Lubricant Quantity in Compressor" .

Keep friction surfaces between clutch and pulley clean. If the surface is contaminated with lubri-
cant, wipe it off by using a clean waste cloth moistened with thinner.

After compressor service operation, turn the compressor shaft by hand more than 5 turns in both
directions. This will equally distribute lubricant inside the compressor. After the compressor is
installed, let the engine idle and operate the compressor for 1 hour.

After replacing the compressor magnet clutch, apply voltage to the new one and check for normal
operation. Refer to ATC-180, "
Removal and Installation for Compressor Clutch"
Precautions for Service EquipmentEJS003WW
RECOVERY/RECYCLING EQUIPMENT
Follow the manufacturer's instructions for machine operation and machine maintenance. Never introduce any
refrigerant other than that specified into the machine.
ELECTRONIC LEAK DETECTOR
Follow the manufacturer's instructions for tester operation and tester maintenance.
RHA861F

ATC-22
LUBRICANT
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LUBRICANTPFP:KLG00
Maintenance of Lubricant Quantity in CompressorEJS003X4
The lubricant in the compressor circulates through the system with the refrigerant. Add lubricant to compres-
sor when replacing any component or after a large refrigerant leakage has occurred. It is important to maintain
the specified amount.
If lubricant quantity is not maintained properly, the following malfunctions may result:

Lack of lubricant: May lead to a seized compressor

Excessive lubricant: Inadequate cooling (thermal exchange interference)
LUBRICANT
Name: NISSAN A/C System Lubricant Type S or equivalent
CHECKING AND ADJUSTING
CAUTION:
If excessive lubricant leakage is noted, do not perform the lubricant return operation.
Start the engine and set the following conditions:
Test Condition

Engine speed: Idling to 1,200 rpm

A/C switch: On

Blower speed: Max. position

Temp. control: Optional [Set so that intake air temperature is 25° to 30° C (77° to 86°F)]

Intake position: Recirculation ( )

Perform lubricant return operation for about ten minutes
Adjust the lubricant quantity according to the following table.
Lubricant Adjusting Procedure for Components Replacement Except Compressor
After replacing any of the following major components, add the correct amount of lubricant to the system.
Amount of lubricant to be added:

*1: If refrigerant leak is small, no addition of lubricant is needed.
Lubricant Adjustment Procedure for Compressor Replacement
1. Before connecting recovery/recycling equipment to vehicle, check recovery/recycling equipment gauges.
No refrigerant pressure should be displayed. If NG, recover refrigerant from equipment lines.
2. Connect recovery/recycling equipment to vehicle. Confirm refrigerant purity in supply tank using recovery/
recycling equipment and refrigerant identifier. If NG, refer to AT C - 5 , "
Contaminated Refrigerant" .
3. Confirm refrigerant purity in vehicle A/C system using recovery/recycling equipment and refrigerant identi-
fier. If NG, refer to AT C - 5 , "
Contaminated Refrigerant" .
4. Discharge refrigerant into the refrigerant recovery/recycling equipment. Measure lubricant discharged into
the recovery/recycling equipment.
5. Drain the lubricant from the “old” (removed) compressor into a graduated container and recover the
amount of lubricant drained.
6. Drain the lubricant from the “new” compressor into a separate, clean container.
7. Measure an amount of new lubricant installed equal to amount drained from “old” compressor. Add this
lubricant to “new” compressor through the suction port opening.
Part replacedLubricant to be added to system
Remarks
Amount of lubricant
m (US fl oz, Imp fl oz)
Front evaporator 75 (2.5, 2.6) —
Rear evaporator 75 (2.5, 2.6) —
Condenser 75 (2.5, 2.6) —
Liquid tank 5 (0.2, 0.2) Add if compressor is not replaced.
In case of refrigerant leak30 (1.0, 1.1) Large leak
— Small leak *1

TROUBLE DIAGNOSIS
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Operational Check (Front)EJS003XL
The purpose of the operational check is to confirm that the system operates properly.
CHECKING MEMORY FUNCTION
1. Set the temperature to 90°F or 32°C.
2. Turn front blower control dial counterclockwise until system
shuts OFF.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous tempera-
ture.
7. Turn front blower control counterclockwise until system shuts
OFF.
If NG, go to trouble diagnosis procedure for ATC-133, "
Memory
Function" .
If OK, continue with next check.
CHECKING BLOWER
1. Press the AUTO switch. Blower should operate on low speed.
The blower symbol should have one blade lit (on display).
2. Turn the front blower control dial again, and continue checking
blower speed and blower symbol until all speeds are checked.
3. Leave blower on MAX speed.
If NG, go to trouble diagnosis procedure for AT C - 9 5 , "
DIAGNOSTIC
PROCEDURE FOR BLOWER MOTOR"ATC-95, "DIAGNOSTIC
PROCEDURE FOR BLOWER MOTOR" .
If OK, continue with next check.Conditions : Engine running and at normal operating temperature
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ATC-60
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
Operational Check (Rear)EJS003XM
The purpose of the operational check is to confirm that the system operates properly.
CHECKING BLOWER
1. Turn the rear blower control dial to switch position "1". Blower
should operate on low speed.
2. Turn the rear blower control dial counterclockwise to switch
position "2", "3", and "4" until all speeds are checked.
3. Leave blower on MAX speed.
If NG, go to trouble diagnosis procedure for ATC-101, "
Rear Blower
Motor Circuit" .
If OK, continue the check.
CHECKING TEMPERATURE DECREASE
1. Rotate temperature and mode dial fully counterclockwise.
2. Check for cold air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation if OK, go to
trouble diagnosis procedure for ATC-121, "
Insufficient Cooling" . If
air mix door motor appears to be malfunctioning, go to ATC-79,
"DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR
(REAR)" .
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Rotate temperature and mode dial clockwise.
2. Check for hot air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation. If OK, go to
trouble diagnosis procedure for ATC-128, "
Insufficient Heating" . If
air mix door motor appears to be malfunctioning, go to ATC-79,
"DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR
(REAR)" .
If OK, continue the check.Conditions : Engine running and at normal operating temperature
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TROUBLE DIAGNOSIS
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8. CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start engine.
2. Check voltage of refrigerant pressure sensor. Refer to ATC-33, "
CONSULT-II Function (HVAC)" .
WITHOUT CONSULT-II
1. Start engine.
2. Check voltage between ECM harness connector F54 terminal
70 (B/W) and ground.
OK or NG
OK >>
WITH CONSULT-II
GO TO 9.

WITHOUT CONSULT-II
GO TO 10.
NG >> Refer to EC-643, "
REFRIGERANT PRESSURE SENSOR" .
9. CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to ATC-33, "
CONSULT-II Function
(HVAC)" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10. CHECK CIRCUIT CONTINUITY BETWEEN BCM AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect BCM connector and front air control connector.
3. Check continuity between BCM harness connector M18 terminal
28 (L/R) and front air control harness connector M49 terminal 10
(L/R).
OK or NG
OK >> GO TO 11.
NG >> Repair harness or connector.
Te r m i n a l s
Condition Voltage (+)
(-)
ECM con-
nectorTe r m i n a l N o .
(Wire color)
F54 70 (B/W) Ground A/C switch: ON Approx. 0.36 - 3.88V
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FRONT BLOWER CONTROL
DIAL ON: FAN ON SIG ON
FRONT BLOWER CONTROL
DIAL OFF: FAN ON SIG OFF
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28 - 10 Continuity should exist.
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TROUBLE DIAGNOSIS
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TROUBLE DIAGNOSES FOR UNUSUAL PRESSURE
Whenever system′s high and/or low side pressure is unusual, diagnose using a manifold gauge. The marker
above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the stan-
dard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air temperature-
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.Pressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge
in refrigeration cycleReduce 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
if 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 cycleEvacuate and recharge sys-
tem.
Engine tends to overheat.Engine cooling systems mal-
function.Check and repair engine cool-
ing system.

An area of the low-pres-
sure pipe is colder than
areas near the evaporator
outlet.

Plates are sometimes cov-
ered 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
adjustmentReplace 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
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Revision: October 20052005 QX56
Memory FunctionEJS003Y0
SYMPTOM: Memory function does not operate.
INSPECTION FLOW
Water Valve CircuitEJS003Y1
COMPONENT DESCRIPTION
Water Valve
The water valve cuts the flow of engine coolant to the front and rear
heater cores to allow for maximum cooling during A/C operation. It is
controlled by the front air control through the water valve relay.
*1ATC-61, "Power Supply and Ground
Circuit for Front Air Control"
*2AT C - 5 7 , "Operational Check (Front)"*3AT C - 5 5 , "A/C System Self-diagnosis
Function"
*4ATC-56, "SELF-DIAGNOSIS CODE
CHART"
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