check engine INFINITI QX4 2005 Factory Service Manual

BRC-42
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: October 20052005 QX56
Yaw Rate/Side/Decel G Sensor System InspectionEFS004XV
CAUTION:
Sudden turns (such as spin turns, acceleration turns), drifting, etc. when VDC function is OFF may
cause the yaw rate/side/decel G sensor system to indicate a problem. This is not a problem if normal
operation can be resumed after restarting the engine.
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
CAUTION:
If vehicle is on turn table at entrance to parking garage, or on other moving surface, VDC OFF indica-
tor lamp may illuminate and CONSULT-II self-diagnosis may indicate yaw rate sensor system malfunc-
tion. However, in this case there is no malfunction in yaw rate sensor system. Take vehicle off of turn
table or other moving surface, and start engine. Results will return to normal.
Is the above displayed in the self-diagnosis display items?
YES >> GO TO 2.
NO >> Inspection End.
2. CONNECTOR INSPECTION
Disconnect the ABS actuator and electric unit (control unit) connector E125 and yaw rate/side/decel G sensor
connector M108.
Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
3. YAW RATE/SIDE/DECEL G SENSOR HARNESS INSPECTION
1. Turn off the ignition switch and disconnect yaw rate/side/decel G sensor connector M108 and ABS actua-
tor and electric unit (control unit) connector E125.
2. Check continuity between the ABS actuator and electric unit (control unit) connector E125 and the yaw
rate/side/decel G sensor connector M108.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace as necessary.
Self-diagnosis results
YAW R AT E S E N S O R
LONGITUDINAL G-SENSOR
LATERAL G-SENSOR
ABS actuator and electric unit
(control unit) harness connector
E125Yaw rate/side/decel G sensor
harness connector M108 Continuity
6 (Y/R) 3 (Y/R)
Ye s 24 (P) 5 (P)
25 (G/R) 1 (G/R)
29 (G/W) 2 (G/W)

TROUBLE DIAGNOSES FOR SYMPTOMS
BRC-59
[VDC/TCS/ABS]
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BRC
Revision: October 20052005 QX56
Long Stopping DistanceEFS004YB
1. CHECK BASE BRAKING SYSTEM PERFORMANCE
1. Disable ABS by disconnecting ABS actuator and electric unit (control unit) connector.
2. Drive vehicle and check brake operation.
NOTE:

Stopping distance may be longer than vehicles without ABS when road condition is slippery.

Driving the vehicle with the ABS actuator and electric unit (control unit) disconnected may induce DTCs
in electrical control units using CAN communication. After the inspection, clear all DTCs. Refer to BRC-
10, "CAN COMMUNICATION" .
OK or NG
OK >> Go to BRC-57, "ABS Works Frequently" .
NG >> Perform Basic Inspection. Refer to BRC-23, "
Basic Inspection" .
ABS Does Not WorkEFS004YC
CAUTION:
The ABS does not operate when the vehicle speed is 10 km/h (6 MPH) or less.
1. CHECK WARNING LAMP ACTIVATION
Turn ignition switch ON and check for warning lamp activation.

Warning lamp should activate for approximately 1 second after turning the ignition switch ON.
OK or NG
OK >> Carry out self-diagnosis. Refer to BRC-29, "SELF-DIAGNOSIS" .
NG >> Go to BRC-60, "
ABS Warning Lamp Does Not Come On When Ignition Switch Is Turned On" .
Pedal Vibration or ABS Operation NoiseEFS004YD
NOTE:
During ABS activation, pedal vibration may be felt and a noise may be heard. This is normal and does not indi-
cate a malfunction.
1. CHECK SYMPTOM
1. Apply brake.
2. Start engine.
Does the symptom occur only when engine is started?
YES >> Carry out self-diagnosis. Refer to BRC-29, "SELF-DIAGNOSIS" .
NO >> GO TO 2.
2. RECHECK SYMPTOM
Does the symptom occur only when electrical equipment switches (such as headlamps) are turned on?
YES >> Check for radio, antenna or related wiring that is routed too close to the ABS actuator and electric
unit (control unit) and reroute as necessary.
NO >> Go to BRC-57, "
ABS Works Frequently" .

TROUBLE DIAGNOSES FOR SYMPTOMS
BRC-61
[VDC/TCS/ABS]
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Revision: October 20052005 QX56
Vehicle Jerks During TCS/VDC ActivationEFS004YG
1. ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) SELF-DIAGNOSIS
Perform ABS actuator and electric unit (control unit) self-diagnosis.
Are self-diagnosis result items displayed?
YES >> After checking and repairing the applicable item, perform the ABS actuator and electric unit (con-
trol unit) self-diagnosis again.
NO >> GO TO 2.
2. ENGINE SPEED SIGNAL INSPECTION
Perform data monitor with CONSULT-II for the ABS actuator and electric unit (control unit).
Is the engine speed at idle 400 rpm or higher?
YES >> GO TO 4.
NO >> GO TO 3.
3. ECM SELF-DIAGNOSIS
Perform ECM self-diagnosis.
Are self-diagnosis result items displayed?
YES >> After checking and repairing the applicable item, perform the ECM self-diagnosis again.
NO >> GO TO 4.
4. TCM SELF-DIAGNOSIS
Perform TCM self-diagnosis.
Are self-diagnosis result items displayed?
YES >> After checking and repairing the applicable item, perform the TCM self-diagnosis again.
NO >> GO TO 5.
5. CONNECTOR INSPECTION
Disconnect the ABS actuator and electric unit (control unit) connector and the ECM connectors and check the
terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace as necessary.
6. CAN COMMUNICATION INSPECTION
Check the CAN communication system. Refer to BRC-55, "
CAN Communication System Inspection" .
OK or NG
OK >> Inspection End.
NG >> Refer to LAN-5, "
CAN COMMUNICATION" .

BRC-62
[VDC/TCS/ABS]
ON-VEHICLE SERVICE
Revision: October 20052005 QX56
ON-VEHICLE SERVICEPFP:00000
Adjustment of Steering Angle Sensor Neutral PositionEFS004YH
After removing/installing or replacing ABS actuator and electric unit (control unit), steering angle sensor, steer-
ing and suspension components which affect wheel alignment or after adjusting wheel alignment, be sure to
adjust neutral position of steering angle sensor before running vehicle.
NOTE:
Adjustment of steering angle sensor neutral position requires CONSULT-II.
1. Stop vehicle with front wheels in straight-ahead position.
2. Connect CONSULT-II and CONSULT-II CONVERTER to data
link connector on vehicle, and turn ignition switch ON (do not
start engine).
3. Touch “ABS”, “WORK SUPPORT” and “ST ANGLE SENSOR
ADJUSTMENT” on CONSULT-II screen in this order.
4. Touch “START”.
CAUTION:
Do not touch steering wheel while adjusting steering angle
sensor.
5. After approximately 10 seconds, touch “END”. (After approxi-
mately 60 seconds, it ends automatically.)
6. Turn ignition switch OFF, then turn it ON again.
7. Run vehicle with front wheels in straight-ahead position, then
stop.
8. Select “DATA MONITOR”, “SELECTION FROM MENU”, and
“STR ANGLE SIG” on CONSULT-II screen. Then check that
“STR ANGLE SIG” is within 0±3.5 deg. If value is more than specification, repeat steps 1 to 5.
9. Erase memory of ABS actuator and electric unit (control unit) and ECM.
10. Turn ignition switch to OFF.
Calibration of Decel G SensorEFS004YI
After removing/installing or replacing ABS actuator and electric unit (control unit), yaw rate/side/decel G sen-
sor, steering and suspension components which affect wheel alignment or after adjusting wheel alignment, be
sure to calibrate the decel G sensor before running vehicle.
NOTE:
Calibration of decel G sensor requires CONSULT-II.
1. Stop vehicle with front wheels in straight-ahead position.
CAUTION:

The work should be done on a level area with an unloaded vehicle.

Keep all the tires inflated to the correct pressures. Adjust the tire pressure to the specified pres-
sure value.
2. Connect CONSULT-II with CONSULT-II CONVERTER to data link connector on vehicle, and turn ignition
switch ON (do not start engine).
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
3. Touch "ABS", "WORK SUPPORT" and "DECEL G SEN CALIBRATION" on CONSULT-II screen in this
order. Refer to BRC-28, "
CONSULT-II BASIC OPERATION PROCEDURE" .
BBIA0369E
WFIA0239E

CO-1
ENGINE COOLING SYSTEM
B ENGINE
CONTENTS
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SECTION CO
A
CO
Revision: October 20052005 QX56 PRECAUTIONS .......................................................... 2
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 2
Precautions for Liquid Gasket .................................. 2
REMOVAL OF LIQUID GASKET SEALING .......... 2
LIQUID GASKET APPLICATION PROCEDURE ..... 2
PREPARATION ........................................................... 4
Special Service Tools ............................................... 4
Commercial Service Tools ........................................ 4
OVERHEATING CAUSE ANALYSIS .......................... 6
Troubleshooting Chart .............................................. 6
COOLING SYSTEM .................................................... 8
Cooling Circuit .......................................................... 8
System Drawing ....................................................... 9
ENGINE COOLANT .................................................. 10
Inspection ............................................................... 10
LEVEL CHECK ................................................... 10
CHECKING COOLING SYSTEM FOR LEAKS ... 10
CHECKING RESERVOIR CAP ........................... 10
CHECKING RADIATOR CAP .............................. 10
Changing Engine Coolant ...................................... 10
DRAINING ENGINE COOLANT ......................... 10
REFILLING ENGINE COOLANT .........................11
FLUSHING COOLING SYSTEM ..........................11
RADIATOR ................................................................ 12
Removal and Installation ........................................ 12
REMOVAL ........................................................... 12
INSTALLATION ................................................... 14INSPECTION AFTER INSTALLATION ................ 14
Checking Radiator .................................................. 14
ENGINE COOLING FAN ........................................... 15
Removal and Installation (Crankshaft Driven Type) ... 15
REMOVAL ........................................................... 15
INSPECTION AFTER REMOVAL ....................... 15
INSTALLATION ................................................... 15
INSPECTION AFTER INSTALLATION ................ 15
Removal and Installation (Motor Driven Type) ....... 16
REMOVAL ........................................................... 16
INSTALLATION ................................................... 16
WATER PUMP .......................................................... 17
Removal and Installation ........................................ 17
REMOVAL ........................................................... 17
INSPECTION AFTER REMOVAL ....................... 17
INSTALLATION ................................................... 17
INSPECTION AFTER INSTALLATION ................ 18
THERMOSTAT AND WATER PIPING ...................... 19
Removal and Installation ........................................ 19
REMOVAL ........................................................... 19
INSPECTION AFTER REMOVAL ....................... 20
INSTALLATION ................................................... 20
INSPECTION AFTER INSTALLATION ................ 20
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 21
Standard and Limit .................................................. 21
ENGINE COOLANT CAPACITY (APPROXI-
MATE) .................................................................. 21
THERMOSTAT .................................................... 21
RADIATOR .......................................................... 21

CO-4Revision: October 2005
PREPARATION
2005 QX56
PREPARATIONPFP:00002
Special Service ToolsEBS00LN0
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolsEBS00LN1
Tool number
(Kent-Moore No.)
Tool nameDescription
KV10111100
(J-37228)
Seal cutterRemoving steel oil pan and rear timing chain
case
WS39930000
(—)
Tube pressurePressing the tube of liquid gasket
EG17650301
(J-33984-A)
Radiator cap tester adapterAdapting radiator cap tester to radiator cap
and radiator filler neck
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (in)
—
(J-23688)
Engine coolant refractometerChecking concentration of ethylene glycol in
engine coolant
NT046
S-NT052
S-NT564
W BIA0539E
Tool nameDescription
Power toolLoosening bolts and nuts
Radiator cap tester Checking radiator and radiator cap
PBIC0190E
PBIC1982E

CO-6Revision: October 2005
OVERHEATING CAUSE ANALYSIS
2005 QX56
OVERHEATING CAUSE ANALYSISPFP:00012
Troubleshooting ChartEBS00LN2
Symptom Check items
Cooling sys-
tem parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
— Thermostat stuck closed —
Damaged finsDust contamination or
paper clogging
Physical damage
Clogged radiator cooling
tubeExcess foreign material
(rust, dirt, sand, etc.)
Water cut valve malfunctionExcess foreign material
(rust, dirt, sand, etc.), phys-
ical damage
Reduced air flowCooling fan does not oper-
ate
Fan assembly — High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud — — —
Improper engine coolant
mixture ratio—— —
Poor engine coolant quality — Engine coolant density —
Insufficient engine coolantEngine coolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tankExhaust gas leaks into
cooling systemCylinder head deterioration
Cylinder head gasket dete-
rioration

OVERHEATING CAUSE ANALYSIS
CO-7
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Revision: October 20052005 QX56
Except cool-
ing system
parts mal-
function— Overload on engineAbusive drivingHigh engine rpm under no
load
Driving in low gear for
extended time
Driving at extremely high
speed
Powertrain system mal-
function
— Installed improper size
wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air
flowBlocked bumper —
— Blocked radiator grilleInstalled car brassiere
Mud contamination or
paper clogging
Blocked radiator —
Blocked condenser
Blocked air flow
Installed large fog lamp Symptom Check items

CO-10Revision: October 2005
ENGINE COOLANT
2005 QX56
ENGINE COOLANTPFP:KQ100
InspectionEBS00LN5
LEVEL CHECK

Check if the engine coolant reservoir tank level is within MIN to
MAX level when engine is cool.

Adjust engine coolant level as necessary.
CHECKING COOLING SYSTEM FOR LEAKS
WAR NIN G:
Never remove the radiator or reservoir cap when the engine is hot. Serious burns could occur from
high-pressure engine coolant escaping from the radiator or reservoir.

To check for leakage, apply pressure to the cooling system at
the reservoir filler neck using suitable tool and Tool.
CAUTION:
Higher pressure than specified may cause radiator damage.
NOTE:
In case that engine coolant decreases, replenish cooling system
with engine coolant.

If any concerns are found, repair or replace damaged parts.
CHECKING RESERVOIR CAP

Check reservoir cap relief pressure using suitable tool and Tool.
NOTE:
Apply engine coolant to the cap seal.

Replace the reservoir cap if there is any damage in the nega-
tive-pressure valve, or if the open-valve pressure is outside of
the limit.
CHECKING RADIATOR CAP
Inspect the radiator cap.
NOTE:
Thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.

Replace the cap if the metal plunger cannot be seen around the edge of the black rubber gasket.

Replace the cap if deposits of waxy residue or other foreign material are on the black rubber gasket or the
metal retainer.
Changing Engine CoolantEBS00LN6
Refer to MA-13, "Changing Engine Coolant" .
DRAINING ENGINE COOLANT
Refer to MA-13, "DRAINING ENGINE COOLANT" .
SM A41 2B
Tool number : EG17650301 (J-33984-A)
Leakage test pressure : 137 kPa (1.4 kg/cm, 20 psi)
WBIA0612E
Tool number : EG17650301 (J-33984-A)
Standard
: 95 - 125 kPa (0.97 - 1.28 kg/cm
2 , 14 - 18 psi)
WBIA0611E

CO-14Revision: October 2005
RADIATOR
2005 QX56
10. Lift up and remove the radiator.
CAUTION:
Do not damage or scratch air conditioner condenser and
radiator core when removing.
INSTALLATION
Installation is in the reverse order of removal.
INSPECTION AFTER INSTALLATION

Check for leaks of 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 and A/T fluid.
Checking RadiatorEBS00LN9
Check radiator for mud or clogging. If necessary, clean radiator as follows.
CAUTION:

Be careful not to bend or damage the radiator fins.

When radiator is cleaned without removal, remove all surrounding parts such as cooling fan, radi-
ator shroud and horns. Then tape the harness and electrical connectors to prevent water from
entering.
1. Apply water by hose to the back side of the radiator core vertically downward.
2. Apply water again to all radiator core surfaces.
3. Stop washing when dirt and debris no longer flow out from the radiator.
4. Blow air into the back side of radiator core vertically downward.

Use compressed air lower than 490 kPa (5 kg/cm2 , 71 psi) and keep distance more than 30 cm (11.8
in).
5. Blow air again into all the radiator core surfaces until no water sprays out.
PBIC1536E