clutch INFINITI QX56 2007 Factory Service Manual

TROUBLE DIAGNOSIS
TF-47
< SERVICE INFORMATION >
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PWORK SUPPORT
When there is no problem with transfer and 4WD system, following symptom in “AUTO” mode may be claimed
by a customer.
• Vibration when accelerating on a low µ road (snow-covered or icy road)
It is possible to deal with these symptoms by changing “CLUTCH FORCE RELEASE LIMIT VALUE”. How-
ever, be careful when changing the values because it may adversely affect driving performance.
NOTE:
A slight shock is felt at a few hertz as if it were being pushed lightly from behind.
Operation Procedure
1. Refer to GI-36, "CONSULT-II Start Procedure".
2. Select “CLUTCH/F RLS LIM ADJ”.
Clutch Force Release Limit Adjustment
1. Current CLUTCH FORCE RELEASE LIMIT value “0.3 kgm”
appears under “CONDITION SETTING” on CONSULT-II display.
2. Touch “1.2” on the display.
3. Display changes to “NOW ADJUSTING” in a short time.
Frequency [Hz] – –×
The value measured by the pulse probe is dis-
played. DUTY-HI (high) [%] – –×
DUTY-LOW (low) [%] – –×
PLS WIDTH-HI [msec] – –×
PLS WIDTH-LOW [msec] – –× Monitored item (Unit)Monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELEC-
TION FROM
MENU
1.2 kg-m : Tight corner braking symptom is alleviated.
However, vibration may occur when acceler-
ating on a low µ road (icy road, etc.).
0.3 kg-m : Initial set value.
0.2 kg-m : Do not set to this value because the tight
corner braking symptom will get worse.
SMT968D
SMT969D

TF-48
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
4. When clutch force release limit value is set to “1.2 kgm”, current
value “0.3 kgm” shown on display will be replaced by “1.2 kgm”
and “ADJUSTMENT COMPLETE” will appear at the same time.
Clutch force release limit value setting is now complete.
Self-Diagnosis ProcedureINFOID:0000000003532528
SELF-DIAGNOSTIC PROCEDURE (WITH CONSULT-II)
Refer to TF-42, "CONSULT-II Function (ALL MODE AWD/4WD)" .
SELF-DIAGNOSTIC PROCEDURE (WITHOUT CONSULT-II)
Description
If the engine starts when there is something wrong with the 4WD system, the 4WD warning lamp turns ON or
flickers in the combination meter. When the system functions properly, the warning lamp turns ON when the
ignition switch is turned to “ON”, and it turns OFF after engine starts. To locate the cause of a problem, start
the self-diagnosis function. The 4WD warning lamp in the combination meter will indicate the problem area by
flickering according to the self-diagnostic results. As for the details of the 4WD warning lamp flickering pat-
terns, refer to "Diagnostic Procedure".
Diagnostic Procedure
1. Warm up engine.
2. Move A/T selector lever to “P” position.
3. Turn 4WD shift switch to “2WD” position.
4. Turn ignition switch “ON” and “OFF” at least twice, and then turn ignition switch “OFF”.
5. Turn 4WD shift switch to “AUTO” position.
6. Turn ignition switch “ON”. (Do not start engine.)
7. 4WD warning lamp ON.
If 4WD warning lamp does not turn ON, refer to TF-104, "
4WD Warning Lamp Does Not Turn ON" .
8. Move A/T selector lever to “R” position.
9. Turn 4WD shift switch to “2WD”, “AUTO” and “2WD” in order.
10. Move A/T selector lever to “D” position.
11. Turn 4WD shift switch to “4H”, “AUTO” and “4H” in order.
12. Move A/T selector lever to “N” position.
13. Turn 4WD shift switch to “AUTO” position.
14. Move A/T selector lever to “P” position.
15. Read the flickering of 4WD warning lamp.
Refer to "Judgement Self-diagnosis".
Judgement Self-diagnosis
When a malfunction is detected, the malfunction route is indicated by flickering of the 4WD warning lamp.
SMT970D

TROUBLE DIAGNOSIS
TF-49
< SERVICE INFORMATION >
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PDIA0227E
Flickering pattern or
flickering conditionItems Malfunction Check items
2Output shaft revolution
signal (from TCM)• Malfunction is detected in output shaft revolution signal
that is output from TCM through CAN communication.
• Improper signal is input while driving.TF-53, "
Output Shaft
Revolution Signal
(TCM)"
3Clutch pressure sole-
noid signal• Proper voltage is not applied to clutch pressure solenoid
valve due to open or short circuit.TF-76, "Clutch Pressure
Solenoid"
4 2-4WD solenoid signal• Proper voltage is not applied to 2-4WD solenoid valve
due to open or short circuit.TF-80, "2-4WD Sole-
noid"
5 Transfer motor• Motor does not operate properly due to open or short cir-
cuit in transfer motor or motor relay.TF-84, "Transfer Motor"
6Vehicle speed signal
(from ABS)• Malfunction is detected in vehicle speed signal that is out-
put from ABS actuator and electric unit (control unit)
through CAN communication.
• Improper signal is input while driving.TF-54, "Vehicle Speed
Sensor (ABS)"
7 CAN communication• Malfunction has been detected from CAN communication
line.TF-99, "CAN Communi-
cation Line"
8 AD converter• AD converter system of transfer control unit is malfunc-
tioning.TF-51, "
Power Supply
Circuit for Transfer Con-
trol Unit"
9Transfer fluid tempera-
ture• Signal voltage from fluid temperature sensor is abnormal-
ly high (Transfer fluid temperature is abnormally low)
while driving.TF-90, "Transfer Fluid
Temperature"
10 Neutral-4LO switch• Improper signal from neutral-4LO switch is input due to
open or short circuit.TF-54, "Neutral-4LO
Switch"
11 Clutch pressure switch• Improper signal from clutch pressure switch is input due
to open or short circuit.
• Malfunction occurs in clutch pressure switch or hydraulic
circuit.TF-92, "Clutch Pressure
Switch"
12 Line pressure switch• Improper signal from line pressure switch is input due to
open or short circuit.
• Malfunction occurs in line pressure switch or hydraulic
circuit.TF-94, "Line Pressure
Switch"
13Engine speed signal
(from ECM)• Malfunction is detected in engine speed signal that is out-
put from ECM through CAN communication.
• Improper signal is input while driving.TF-76, "Engine Speed
Signal (ECM)"
14Throttle position sen-
sor (from ECM)• Malfunction is detected in accelerator pedal position sig-
nal that is output from ECM through CAN communication.
• Signal voltage from accelerator pedal position sensor is
abnormally high or low.TF-97, "Throttle Posi-
tion Signal (ECM)"
15 Power supply• Power supply voltage for transfer control unit is abnor-
mally low while driving.TF-51, "
Power Supply
Circuit for Transfer Con-
trol Unit"
16 4WD shift switch• More than two switch inputs are simultaneously detected
due to short circuit of 4WD shift switch.TF-57, "4WD Shift
Switch"

TF-50
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
CAUTION:
• If “CAN communication” is displayed with other DTCs, first perform the trouble diagnosis for CAN communication line.
• If “ABS operation signal”, “VDC operation signal" or “TCS operation signal" is displayed, first perform the trouble diagnosis
for ABS system.
• If “Output shaft revolution signal” is displayed, first perform the trouble diagnosis for A/T system.
NOTE:
• If "actuator position switch" or “actuator circuit” is displayed, first erase self-diagnostic results. ("Actuator position switch" or “actuator
circuit” may be displayed after installing transfer control unit or transfer assembly.)
• If “clutch pressure switch” or “line pressure switch” is displayed only while driving in reverse, check the continuity of “R” position on A/
T PNP switch. When there is nothing wrong with the electrical system, check the hydraulic system.
ERASE SELF-DIAGNOSIS
• In order to make it easier to find the cause of hard-to-duplicate malfunctions, malfunction information is
stored into the control unit as necessary during use by the user. This memory is not erased no matter how
many times the ignition switch is turned ON and OFF.
• However, this information is erased by turning ignition switch “OFF” after performing self-diagnostics or by
erasing the memory using the CONSULT-II.
17ABS operation signal
(from ABS)• Malfunction is detected in ABS operation signal that is
output from ABS actuator and electric unit (control unit)
through CAN communication.TF-97, "ABS Operation
Signal (ABS)"
18 Wait detection switch• Improper signal from wait detection switch is input due to
open or short circuit.TF-60, "Wait Detection
Switch"
19 Actuator motor• Motor does not operate properly due to open or short cir-
cuit in actuator motor.
• Malfunction is detected in the actuator motor. (When
4WD shift switch is operated and actuator motor is not
operated)
• Malfunction is detected in transfer shift high relay and
transfer shift low relay.TF-64, "
Actuator Motor",
TF-51, "
Power Supply
Circuit for Transfer Con-
trol Unit"
20Actuator position
switch• Improper signal from actuator position switch is input due
to open or short circuit.
• Malfunction is detected in the actuator position switch.TF-69, "Actuator Posi-
tion Switch"
21 Actuator circuit• Transfer control device actuator circuit is shorted or open.
(Malfunctions are detected when motor relay circuit is
open/shorted or relay transfer shift circuit is open/short-
ed.)
• Malfunction occurs in transfer control device drive circuit.TF-72, "
Transfer Control
Device"
• Malfunction is detected in transfer shut off relay.TF-51, "
Power Supply
Circuit for Transfer Con-
trol Unit"
22VDC operation signal
(from VDC)• Malfunction is detected in VDC operation signal that is
output from ABS actuator and electric unit (control unit)
through CAN communication.TF-98, "VDC Operation
Signal (ABS)"
23TCS operation signal
(from TCS)• Malfunction is detected in TCS operation signal that is
output from ABS actuator and electric unit (control unit)
through CAN communication.TF-98, "TCS Operation
Signal (ABS)"
24PNP switch signal
(from TCM)• When A/T PNP switch signal is malfunctioning or commu-
nication error between the vehicles.TF-63, "PNP Switch
Signal (TCM)"
Repeats flickering
every 2 to 5 sec.— Circuits that the self-diagnosis covers have no malfunction. —
Repeats flickering
every 0.25 sec.Data erase display• Power supply failure of memory back-up.
• Battery performance is poor.TF-51, "
Power Supply
Circuit for Transfer Con-
trol Unit"
No flickeringPNP switch or 4WD
shift switch• PNP switch or 4WD shift switch circuit is shorted or open.TF-63, "
PNP Switch
Signal (TCM)", TF-57,
"4WD Shift Switch"
Flickering pattern or
flickering conditionItems Malfunction Check items

TF-76
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
7.PERFORM SELF-DIAGNOSIS (WITH CONSULT-II)
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Touch “ERASE”.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Perform the self-diagnosis again.
Is the
“SHIFT ACT CIR [P1819]” displayed?
YES >> Replace transfer control unit. Refer to TF-115, "Removal and Installation".
NO >> Inspection End.
8.PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-II)
Without CONSULT-II1. Perform the self-diagnosis and then erase self-diagnostic results. Refer to TF-48, "Self-Diagnosis Proce-
dure" and TF-48, "Self-Diagnosis Procedure".
2. Perform the self-diagnosis again.
Do the self-diagnostic results indicate transfer control device?
YES >> Replace transfer control unit. Refer to TF-121, "Removal and Installation".
NO >> Inspection End.
Engine Speed Signal (ECM)INFOID:0000000003532540
DIAGNOSTIC PROCEDURE
1.CHECK DTC WITH ECM
Perform self-diagnosis with ECM. Refer to E C - 111 , "
CONSULT-II Function (ENGINE)" .
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 2.
2.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value".
OK or NG
OK >> GO TO 3.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Perform self-diagnosis with ECM again. Refer to E C - 111 , "
CONSULT-II Function (ENGINE)" .
Clutch Pressure SolenoidINFOID:0000000003532541
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Monitored item Content Condition Display value
DUTY SOLENOID [%]Condition of clutch pres-
sure solenoid• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 2WD 4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO4%

TROUBLE DIAGNOSIS FOR SYSTEM
TF-77
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Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
DIAGNOSTIC PROCEDURE
1.CHECK CLUTCH PRESSURE SIGNAL
With CONSULT-II1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Read out the value of “DUTY SOLENOID”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 7.
NG >> GO TO 2.
Te r m i n a lWire
colorItem Condition Data (Approx.)
10 L/W Transfer dropping resistor• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: AUTO 4 - 14V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
19 LClutch pressure solenoid
valve• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: AUTO 1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
Condition Display value
• Vehicle stopped
• Engine running
• A/T selector lever “N” position
• Brake pedal depressed4WD shift switch: 2WD 4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO4%
SDIA2718E
Connector Terminal ConditionVoltage
(Approx.)
E142 10 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch:
AUTO4 - 14V
4WD shift switch:
2WD, 4H or 4LOLess than
1V
19 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch:
AUTO1.5 - 3V
4WD shift switch:
2WD, 4H or 4LOLess than
1V
SDIA2719E

TF-78
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
2.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND CLUTCH PRESSURE SOLENOID
VA LV E
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector, transfer terminal cord assembly harness connector
and transfer dropping resistor.
3. Check continuity between transfer control unit harness connec-
tor E142 terminal 19 and transfer terminal cord assembly har-
ness connector F56 terminal 6.
4. Check continuity between transfer dropping resistor harness
connector E135 terminal 2 and transfer terminal cord assembly
harness connector F56 terminal 6.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND TRANSFER DROPPING RESISTOR
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and transfer dropping resistor harness connector.
3. Check continuity between transfer control unit harness connec-
tor E142 terminal 10 and transfer dropping resistor harness con-
nector E135 terminal 1.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer terminal cord assembly harness connector.
3. Check continuity between transfer terminal cord assembly har-
ness connector F56 terminal 19 and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors. Continuity should exist.
SDIA2720E
Continuity should exist.
SDIA2721E
Continuity should exist.
SDIA2722E
Continuity should exist.
SDIA2723E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-79
< SERVICE INFORMATION >
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5.CHECK CLUTCH PRESSURE SOLENOID
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer terminal cord assembly harness connector.
3. Check resistance between transfer terminal cord assembly ter-
minals 6 and 19.
OK or NG
OK >> GO TO 6.
NG >> Replace clutch pressure solenoid. Refer to TF-22,
"Location of Electrical Parts".
6.CHECK TRANSFER DROPPING RESISTOR
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer dropping resistor harness connector. Refer to TF-22, "
Location of Electrical Parts".
3. Check resistance between transfer dropping resistor terminals 1
and 2.
OK or NG
OK >> GO TO 7.
NG >> Replace transfer dropping resistor. Refer to TF-22,
"Location of Electrical Parts".
7.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value".
OK or NG
OK >> GO TO 8.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
8.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Replace transfer control unit. Refer to TF-115, "
Removal and Installation".
COMPONENT INSPECTION
Clutch Pressure Solenoid
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer terminal cord assembly harness connector.6 - 19 : Approx. 3.0 - 3.4 Ω
WDIA0225E
1 - 2 : Approx. 11.2 - 12.8 Ω
SDIA2725E

TF-80
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
3. Check resistance between transfer terminal cord assembly ter-
minals 6 and 19.
4. If NG, replace clutch pressure solenoid. Refer to TF-22, "
Loca-
tion of Electrical Parts" .
Transfer Dropping Resistor
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer dropping resistor harness connector.
3. Check resistance between transfer dropping resistor terminals 1
and 2.
4. If NG, replace transfer dropping resistor. Refer to TF-22, "
Loca-
tion of Electrical Parts".
2-4WD SolenoidINFOID:0000000003532542
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
6 - 19 : Approx. 3.0 - 3.4 Ω
WDIA0225E
1 - 2 : Approx. 11.2 - 12.8 Ω
SDIA2725E
Monitored item Content Condition Display value
2-4WD SOL [ON/OFF]Condition of 2-4WD shift
solenoid valve• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operat-
ing.)OFF
4WD shift switch: 4H
(“Wait” function is operat-
ing.)OFF
2-4WD SOL MON [ON/
OFF]Check signal for transfer
control unit signal output• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operat-
ing.)OFF
4WD shift switch: 4H
(“Wait” function is operat-
ing.)OFF

TF-92
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Replace transfer control unit. Refer to TF-115, "
Removal and Installation".
COMPONENT INSPECTION
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer terminal cord assembly harness connector.
3. Check resistance between transfer terminal cord assembly har-
ness connector F56 terminals 2 and 3.
4. If NG, replace the transfer fluid temperature sensor. Refer to TF-
22, "Location of Electrical Parts".
Clutch Pressure SwitchINFOID:0000000003532545
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
DIAGNOSTIC PROCEDURE
1.CHECK CLUTCH PRESSURE SWITCH SIGNAL
With CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
Temperature °C (°F) Resistance (Approx.)
20 (68) 2.5 kΩ
80 (176) 0.3 kΩ
WDIA0188E
Monitored item [Unit] Content Condition Display value
CL PRES SW [ON /
OFF]Condition of clutch pres-
sure switch• Vehicle stopped
• Engine running
• A/T selector lever “D” position
• 4WD shift switch: AUTO or 4H (“Wait” function is not
operating.)ON
• Vehicle stopped
• Engine running
• 4WD shift switch: 2WD (“Wait” function is not operat-
ing.)OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
34 BR Clutch pressure switch• Vehicle stopped
• Engine running
• A/T selector le-
ver “D” position4WD shift switch: AUTO or 4H (“Wait” func-
tion is not operating.)0V
• Vehicle stopped
• Engine running4WD shift switch: 2WD (“Wait” function is
not operating.)Battery voltage