2005 INFINITI QX4 heater

ATC-192
REFRIGERANT LINES
Revision: October 20052005 QX56
NOTE:
Keep the probe inserted for at least 10 seconds. Use caution not to contaminate the probe tip with
water or dirt that may be in the drain hose.
5. If a leak is detected, verify at least once by blowing compressed air into the area of the suspected leak,
then repeat the leak check.
6. Do not stop when one leak is found. Continue to check for additional leaks at all system components and
connections.
7. If no leaks are found, perform steps 8 - 11.
8. Start the engine.
9. Set the heater A/C controls as follows:
NOTE:
For the automatic system, turn OFF the automatic controls and set the heater A/C controls manually.
a. A/C switch to ON
b. Air flow to VENT mode
c. Intake position to RECIRCULATION mode
d. Temperature to MAX cold
e. Blower speed to HIGH
10. Run the engine at 1,500 rpm for at least 2 minutes.
11. Turn the engine OFF and perform the leak check again following
steps 4 through 6 above.
Refrigerant leaks should be checked immediately after turning
the engine OFF. Begin with the leak detector at the compressor.
The pressure on the high pressure side will gradually drop after
the refrigerant circulation stops and pressure on the low pres-
sure side will gradually rise, as shown in the graph. Some leaks
are more easily detected when the pressure is high.
12. Before connecting the recovery/recycling recharging equipment to the vehicle, check the recovery/recy-
cling recharging equipment gauges. No refrigerant pressure should be displayed. If pressure is displayed,
recover the refrigerant from the equipment lines and then check the refrigerant purity.
13. Confirm refrigerant purity in supply tank using recovery/recycling recharging equipment and refrigerant
identifier equipment (J-41810-NI).
14. Confirm the refrigerant purity in the vehicle's A/C system using recovery/recycling recharging equipment
and refrigerant identifier equipment (J-41810-NI).
15. Discharge the A/C system using recovery/recycling recharging equipment. Repair the leaking fitting or
component as necessary.
16. Evacuate and recharge the A/C system and perform the leak test to confirm that there are no refrigerant
leaks.
17. Conduct the Operational Check to ensure system works properly. Refer to AT C - 5 7 , "
Operational Check
(Front)" and ATC-60, "Operational Check (Rear)" .
SHA8 39 E

AUDIO
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Revision: October 20052005 QX56
NOTE:
1. The following noise results from variations in field strength, such as fading noise and multi-path noise, or
external noise from trains and other sources. It is not a malfunction.

Fading noise: This noise occurs because of variations in the field strength in a narrow range due to moun-
tains or buildings blocking the signal.

Multi-path noise: This noise results from the waves sent directly from the broadcast station arriving at the
antenna at a different time from the waves which reflect off mountains or buildings.
FOR CD ONLY
Noise InspectionEKS00BIH
The vehicle itself can be a source of noise if noise prevention parts or electrical equipment is malfunctioning.
Check if noise is caused and/or changed by engine speed, ignition switch turned to each position, and opera-
tion of each piece of electrical equipment, and determine the cause.
NOTE:
The source of the noise can be found easily by listening to the noise while removing the fuses of electrical
components, one by one.
TYPE OF NOISE AND POSSIBLE CAUSE
Symptom Possible cause
CD cannot be inserted.

CD

Audio unit CD cannot be ejected.
The CD cannot be played.
The sound skips, stops suddenly, or is distorted.
Occurrence condition Possible cause
Occurs only when engine is ON.A continuous growling noise occurs. The speed of
the noise varies with changes in the engine speed.

Ignition components
A whistling noise occurs while the engine speed is
high. A booming noise occurs while the engine is
running and the lighting switch is ON.

Generator
The occurrence of the noise is linked with the operation of the fuel pump.

Fuel pump condenser
Noise only occurs when various
electrical components are oper-
ating.A cracking or snapping sound occurs with the
operation of various switches.

Relay malfunction, audio unit malfunction
The noise occurs when various motors are operat-
ing.

Motor case ground

Motor
The noise occurs constantly, not just under certain conditions.

Rear defogger coil malfunction

Open circuit in printed heater

Poor ground of antenna amplifier or
antenna feeder line
A cracking or snapping sound occurs while the vehicle is being driven, especially
when it is vibrating excessively.

Ground wire of body parts

Ground due to improper part installation

Wiring connections or a short circuit

THERMOSTAT AND WATER PIPING
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Revision: October 20052005 QX56
THERMOSTAT AND WATER PIPINGPFP:21200
Removal and InstallationEBS00LND
REMOVAL
Removal of Thermostat
1. Drain engine coolant from the radiator. Refer to MA-13, "DRAINING ENGINE COOLANT" .
CAUTION:
Perform when engine is cold.
2. Remove the air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
3. Remove the engine room cover using power tools.
4. Disconnect the water suction hose from the water inlet.
5. Remove the water inlet and thermostat.
Removal of Thermostat Housing, Water Outlet and Heater Pipe
1. Remove the intake manifold. Refer to EM-15, "REMOVAL" .
2. Remove the thermostat housing, water outlet and heater pipe.
Removal of Water Cut Valve
1. Drain the engine coolant from the radiator. Refer to MA-13, "DRAINING ENGINE COOLANT" .
KBIA2501E
1. Heater pipe 2. Gasket 3. Water outlet
4. Gasket 5. O-ring 6. O-ring
7. Thermostat housing 8. Rubber ring 9. Thermostat
10. Water inlet 11. Water suction hose 12. Water suction pipe
13. Gasket 14. Heater pipe

CO-20Revision: October 2005
THERMOSTAT AND WATER PIPING
2005 QX56
CAUTION:
Perform when the engine is cold.
2. Remove the air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
3. Remove the engine room cover using power tool.
4. Disconnect the heater hose (heater core side).
5. Remove the heater hose bracket.
6. Disconnect the water cut valve connector.
7. Remove the water cut valve.
INSPECTION AFTER REMOVAL

Place a thread so that it is caught in the valve of the thermostat.
Immerse fully in a container filled with water. Heat while stirring.

The valve opening temperature is the temperature at which the
valve opens and falls from the thread.

Continue heating. Check the full-open lift amount.

After checking the full-open lift amount, lower the water temper-
ature and check the valve closing temperature.
Standard values:
INSTALLATION
Installation is in the reverse order of removal.
Installation of Thermostat

Install the thermostat with the whole circumference of each
flange part fit securely inside the rubber ring as shown.

Install the thermostat with the jiggle valve facing upwards.
Installation of Water Outlet Pipe and Heater Pipe
First apply a neutral detergent to the O-rings, then quickly insert the insertion parts of the water outlet pipe and
heater pipe into the installation holes.
INSPECTION AFTER INSTALLATION

Check for leaks of the engine coolant. Refer to CO-10, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up the engine. Visually check for leaks of the engine coolant.
SL C2 52 B
Thermostat
Valve opening temperature 80 - 84°C (176 - 183° F)
Full-open lift amount More than 10 mm/ 95°C (0.39 in/ 203°F)
Valve closing temperature 77°C (171°F) or higher
KBIA2502E

EC-2Revision: October 20052005 QX56 TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT .......................................................................156
Description ............................................................156
Diagnostic Procedure ...........................................156
POWER SUPPLY AND GROUND CIRCUIT ...........157
Wiring Diagram .....................................................157
Diagnostic Procedure ...........................................158
Ground Inspection ................................................162
DTC U1000, U1001 CAN COMMUNICATION LINE .163
Description ............................................................163
On Board Diagnosis Logic ....................................163
DTC Confirmation Procedure ...............................163
Wiring Diagram .....................................................164
Diagnostic Procedure ...........................................165
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER .166
Description ............................................................166
CONSULT-II Reference Value in Data Monitor Mode
.166
On Board Diagnosis Logic ....................................166
DTC Confirmation Procedure ...............................167
Wiring Diagram .....................................................168
Diagnostic Procedure ...........................................171
Component Inspection ..........................................173
Removal and Installation ......................................173
DTC P0101 MAF SENSOR .....................................174
Component Description ........................................174
CONSULT-II Reference Value in Data Monitor Mode
.174
On Board Diagnosis Logic ....................................174
DTC Confirmation Procedure ...............................175
Overall Function Check ........................................176
Wiring Diagram .....................................................177
Diagnostic Procedure ...........................................178
Component Inspection ..........................................181
Removal and Installation ......................................182
DTC P0102, P0103 MAF SENSOR .........................183
Component Description ........................................183
CONSULT-II Reference Value in Data Monitor Mode
.183
On Board Diagnosis Logic ....................................183
DTC Confirmation Procedure ...............................184
Wiring Diagram .....................................................185
Diagnostic Procedure ...........................................186
Component Inspection ..........................................189
Removal and Installation ......................................190
DTC P0112, P0113 IAT SENSOR ...........................191
Component Description ........................................191
On Board Diagnosis Logic ....................................191
DTC Confirmation Procedure ...............................191
Wiring Diagram .....................................................192
Diagnostic Procedure ...........................................193
Component Inspection ..........................................194
Removal and Installation ......................................194
DTC P0117, P0118 ECT SENSOR ..........................195
Component Description ........................................195
On Board Diagnosis Logic ....................................195
DTC Confirmation Procedure ...............................196
Wiring Diagram .....................................................197
Diagnostic Procedure ...........................................198Component Inspection .......................................... 199
Removal and Installation ....................................... 200
DTC P0122, P0123 TP SENSOR ............................ 201
Component Description ........................................ 201
CONSULT-II Reference Value in Data Monitor Mode
. 201
On Board Diagnosis Logic .................................... 201
DTC Confirmation Procedure ................................ 202
Wiring Diagram ..................................................... 203
Diagnostic Procedure ............................................ 204
Component Inspection .......................................... 207
Removal and Installation ....................................... 207
DTC P0125 ECT SENSOR ...................................... 208
Component Description ........................................ 208
On Board Diagnosis Logic .................................... 208
DTC Confirmation Procedure ................................ 209
Diagnostic Procedure ............................................ 209
Component Inspection .......................................... 210
Removal and Installation ....................................... 210
DTC P0127 IAT SENSOR ........................................211
Component Description ........................................211
On Board Diagnosis Logic ....................................211
DTC Confirmation Procedure ................................211
Diagnostic Procedure ............................................ 212
Component Inspection .......................................... 213
Removal and Installation ....................................... 213
DTC P0128 THERMOSTAT FUNCTION ................. 214
On Board Diagnosis Logic .................................... 214
DTC Confirmation Procedure ................................ 214
Diagnostic Procedure ............................................ 214
Component Inspection .......................................... 215
Removal and Installation ....................................... 215
DTC P0138, P0158 HO2S2 ..................................... 216
Component Description ........................................ 216
CONSULT-II Reference Value in Data Monitor Mode
. 216
On Board Diagnosis Logic .................................... 216
DTC Confirmation Procedure ................................ 217
Wiring Diagram ..................................................... 218
Diagnostic Procedure ............................................ 221
Component Inspection .......................................... 223
Removal and Installation ....................................... 224
DTC P0139, P0159 HO2S2 ..................................... 225
Component Description ........................................ 225
CONSULT-II Reference Value in Data Monitor Mode
. 225
On Board Diagnosis Logic .................................... 225
DTC Confirmation Procedure ................................ 226
Overall Function Check ......................................... 226
Wiring Diagram ..................................................... 228
Diagnostic Procedure ............................................ 231
Component Inspection .......................................... 234
Removal and Installation ....................................... 235
DTC P0171, P0174 FUEL INJECTION SYSTEM
FUNCTION .............................................................. 236
On Board Diagnosis Logic .................................... 236
DTC Confirmation Procedure ................................ 236
Wiring Diagram ..................................................... 238
Diagnostic Procedure ............................................ 240

EC-4Revision: October 20052005 QX56 Diagnostic Procedure ...........................................338
Component Inspection ..........................................340
DTC P0453 EVAP CONTROL SYSTEM PRESSURE
SENSOR ..................................................................341
Component Description ........................................341
CONSULT-II Reference Value in Data Monitor Mode
.341
On Board Diagnosis Logic ....................................341
DTC Confirmation Procedure ...............................342
Wiring Diagram .....................................................343
Diagnostic Procedure ...........................................344
Component Inspection ..........................................348
DTC P0455 EVAP CONTROL SYSTEM .................349
On Board Diagnosis Logic ....................................349
DTC Confirmation Procedure ...............................350
Diagnostic Procedure ...........................................351
DTC P0456 EVAP CONTROL SYSTEM .................357
On Board Diagnosis Logic ....................................357
DTC Confirmation Procedure ...............................358
Overall Function Check ........................................359
Diagnostic Procedure ...........................................360
DTC P0460 FUEL LEVEL SENSOR .......................366
Component Description ........................................366
On Board Diagnosis Logic ....................................366
DTC Confirmation Procedure ...............................366
Diagnostic Procedure ...........................................367
Removal and Installation ......................................367
DTC P0461 FUEL LEVEL SENSOR .......................368
Component Description ........................................368
On Board Diagnosis Logic ....................................368
Overall Function Check ........................................368
Diagnostic Procedure ...........................................369
Removal and Installation ......................................369
DTC P0462, P0463 FUEL LEVEL SENSOR CIR-
CUIT ........................................................................370
Component Description ........................................370
On Board Diagnosis Logic ....................................370
DTC Confirmation Procedure ...............................370
Diagnostic Procedure ...........................................371
Removal and Installation ......................................371
DTC P0500 VSS ......................................................372
Description ............................................................372
On Board Diagnosis Logic ....................................372
DTC Confirmation Procedure ...............................372
Overall Function Check ........................................372
Diagnostic Procedure ...........................................373
DTC P0506 ISC SYSTEM .......................................374
Description ............................................................374
On Board Diagnosis Logic ....................................374
DTC Confirmation Procedure ...............................374
Diagnostic Procedure ...........................................375
DTC P0507 ISC SYSTEM .......................................376
Description ............................................................376
On Board Diagnosis Logic ....................................376
DTC Confirmation Procedure ...............................376
Diagnostic Procedure ...........................................377
DTC P0550 PSP SENSOR ......................................378
Component Description ........................................378
CONSULT-II Reference Value in Data Monitor Mode . 378
On Board Diagnosis Logic .................................... 378
DTC Confirmation Procedure ................................ 378
Wiring Diagram ..................................................... 379
Diagnostic Procedure ............................................ 380
Component Inspection .......................................... 382
Removal and Installation ....................................... 382
DTC P0605 ECM ..................................................... 383
Component Description ........................................ 383
On Board Diagnosis Logic .................................... 383
DTC Confirmation Procedure ................................ 383
Diagnostic Procedure ............................................ 384
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1
HEATER ................................................................... 386
Description ............................................................ 386
CONSULT-II Reference Value in Data Monitor Mode
. 386
On Board Diagnosis Logic .................................... 386
DTC Confirmation Procedure ................................ 386
Wiring Diagram ..................................................... 387
Diagnostic Procedure ............................................ 390
Component Inspection .......................................... 392
Removal and Installation ....................................... 392
DTC P1065 ECM POWER SUPPLY ........................ 393
Component Description ........................................ 393
On Board Diagnosis Logic .................................... 393
DTC Confirmation Procedure ................................ 393
Wiring Diagram ..................................................... 394
Diagnostic Procedure ............................................ 395
DTC P1121 ELECTRIC THROTTLE CONTROL
ACTUATOR ............................................................. 397
Component Description ........................................ 397
On Board Diagnosis Logic .................................... 397
DTC Confirmation Procedure ................................ 397
Diagnostic Procedure ............................................ 398
DTC P1122 ELECTRIC THROTTLE CONTROL
FUNCTION .............................................................. 399
Description ............................................................ 399
On Board Diagnosis Logic .................................... 399
DTC Confirmation Procedure ................................ 399
Wiring Diagram ..................................................... 400
Diagnostic Procedure ............................................ 401
Component Inspection .......................................... 404
Removal and Installation ....................................... 404
DTC P1124, P1126 THROTTLE CONTROL MOTOR
RELAY ..................................................................... 405
Component Description ........................................ 405
CONSULT-II Reference Value in Data Monitor Mode
. 405
On Board Diagnosis Logic .................................... 405
DTC Confirmation Procedure ................................ 405
Wiring Diagram ..................................................... 407
Diagnostic Procedure ............................................ 408
DTC P1128 THROTTLE CONTROL MOTOR ......... 410
Component Description ........................................ 410
On Board Diagnosis Logic .................................... 410
DTC Confirmation Procedure ................................ 410
Wiring Diagram .....................................................411
Diagnostic Procedure ............................................ 412

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Revision: October 20052005 QX56 DTC P2135 TP SENSOR ........................................ 604
Component Description ........................................ 604
CONSULT-II Reference Value in Data Monitor Mode
. 604
On Board Diagnosis Logic ................................... 604
DTC Confirmation Procedure ............................... 605
Wiring Diagram .................................................... 606
Diagnostic Procedure ........................................... 607
Component Inspection ......................................... 610
Removal and Installation ...................................... 610
DTC P2138 APP SENSOR ...................................... 611
Component Description ......................................... 611
CONSULT-II Reference Value in Data Monitor Mode
.. 611
On Board Diagnosis Logic .................................... 611
DTC Confirmation Procedure ............................... 612
Wiring Diagram .................................................... 613
Diagnostic Procedure ........................................... 614
Component Inspection ......................................... 618
Removal and Installation ...................................... 618
IGNITION SIGNAL .................................................. 619
Component Description ........................................ 619
Wiring Diagram .................................................... 620
Diagnostic Procedure ........................................... 625
Component Inspection ......................................... 629
Removal and Installation ...................................... 630
INJECTOR CIRCUIT ............................................... 631
Component Description ........................................ 631
CONSULT-II Reference Value in Data Monitor Mode
. 631
Wiring Diagram .................................................... 632
Diagnostic Procedure ........................................... 633
Component Inspection ......................................... 636
Removal and Installation ...................................... 636
FUEL PUMP CIRCUIT ............................................ 637
Description ........................................................... 637
CONSULT-II Reference Value in Data Monitor Mode
. 637
Wiring Diagram .................................................... 638
Diagnostic Procedure ........................................... 639
Component Inspection ......................................... 642
Removal and Installation ...................................... 642
REFRIGERANT PRESSURE SENSOR ................. 643
Component Description ........................................ 643Wiring Diagram .....................................................644
Diagnostic Procedure ...........................................645
Removal and Installation ......................................647
ELECTRICAL LOAD SIGNAL ................................648
Description ............................................................648
CONSULT-II Reference Value in Data Monitor Mode
.648
Diagnostic Procedure ...........................................648
ICC BRAKE SWITCH .............................................649
Component Description ........................................649
CONSULT-II Reference Value in Data Monitor Mode
.649
Wiring Diagram .....................................................650
Diagnostic Procedure ...........................................651
Component Inspection ..........................................656
ASCD BRAKE SWITCH .........................................657
Component Description ........................................657
CONSULT-II Reference Value in Data Monitor Mode
.657
Wiring Diagram .....................................................658
Diagnostic Procedure ...........................................659
Component Inspection ..........................................663
ASCD INDICATOR ..................................................664
Component Description ........................................664
CONSULT-II Reference Value in Data Monitor Mode
.664
Wiring Diagram .....................................................665
Diagnostic Procedure ...........................................666
MIL AND DATA LINK CONNECTOR ......................667
Wiring Diagram .....................................................667
SERVICE DATA AND SPECIFICATIONS (SDS) ....669
Fuel Pressure .......................................................669
Idle Speed and Ignition Timing .............................669
Calculated Load Value ..........................................669
Mass Air Flow Sensor ...........................................669
Intake Air Temperature Sensor .............................669
Engine Coolant Temperature Sensor ...................669
A/F Sensor 1 Heater .............................................669
Heated Oxygen sensor 2 Heater ..........................669
Crankshaft Position Sensor (POS) .......................669
Camshaft Position Sensor (PHASE) ....................669
Throttle Control Motor ...........................................669
Injector ..................................................................670
Fuel Pump ............................................................670

ON BOARD DIAGNOSTIC (OBD) SYSTEM
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Revision: October 20052005 QX56
If, during the state emissions inspection, the SRT indicates “CMPLT” for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT indicates “INCMP” for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
If MIL is ON during the state emissions inspection, the vehicle is also returned to the customer untested even
though the SRT indicates “CMPLT” for all test items. Therefore, it is important to check SRT (“CMPLT”) and
DTC (No DTCs) before the inspection.
SRT Item
The table below shows required self-diagnostic items to set the SRT to “CMPLT”.
*: If completion of several SRTs is required, perform driving patterns (DTC confirmation procedure), one by one based on the priority for
models with CONSULT-II.
SRT Set Timing
SRT is set as “CMPLT” after self-diagnosis has been performed one or more times. Completion of SRT is
done regardless of whether the result is OK or NG. The set timing is different between OK and NG results and
is shown in the table below.
OK: Self-diagnosis is carried out and the result is OK.SRT item
(CONSULT-II indication)Performance
Priority*Required self-diagnostic items to set the SRT to “CMPLT”Corresponding
DTC No.
CATALYST 2 Three way catalyst function P0420, P0430
EVAP SYSTEM 2 EVAP control system purge flow monitoring P0441
1 EVAP control system P0442
2 EVAP control system P0456
HO2S 2 Air fuel ratio (A/F) sensor 1 P1278, P1288
Air fuel ratio (A/F) sensor 1 P1279, P1289
Heated oxygen sensor 2 P0139, P0159
Heated oxygen sensor 2 P1146, P1166
Heated oxygen sensor 2 P1147, P1167
HO2S HTR 2 Air fuel ratio (A/F) sensor 1 heater P1031, P1032,
P1051, P1052
Heated oxygen sensor 2 heater P0037, P0038,
P0057, P0058
Self-diagnosis resultExample
DiagnosisIgnition cycle
← ON → OFF ← ON → OFF ← ON → OFF ← ON →
All OK Case 1 P0400 OK (1) — (1) OK (2) — (2)
P0402 OK (1) — (1) — (1) OK (2)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “CMPLT” “CMPLT” “CMPLT” “CMPLT”
Case 2 P0400 OK (1) — (1) — (1) — (1)
P0402 — (0) — (0) OK (1) — (1)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “INCMP” “INCMP” “CMPLT” “CMPLT”
NG exists Case 3 P0400 OK OK — —
P0402 — — — —
P1402 NG — NGNG
(Consecutive
NG)
(1st trip)
DTC1st trip DTC — 1st trip DTCDTC
(= MIL ON)
SRT of EGR “INCMP” “INCMP” “INCMP” “CMPLT”