INFINITI QX56 2010 Factory Service Manual

DIAGNOSIS SYSTEM (TRANSFER CONTROL UNIT)DLN-19
< FUNCTION DIAGNOSIS > [ATX14B]
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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.
Self-diagnosis example
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 igni tion switch OFF after performing self-diagnostics or by
erasing the memory using the CONSULT-III.
DATA MONITOR MODE
Operation Procedure
1. Connect CONSULT-III.
2. Touch DATA MONITOR.
3. Select from SELECT MONITOR ITEM, screen of data monitor mode is displayed.
NOTE:
When malfunction is detected, CONSUL T-III performs REAL-TIME DIAGNOSIS.
Also, any malfunction detected while in th is mode will be displayed at real time.
Display Item List
×: Standard –: Not applicable
PDIA0227E
Monitored item (Unit) Monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELEC-
TION FROM MENU
VHCL/S SEN·FR [km/h] or [mph] ×–×Wheel speed calculated by ABS actuator and
electric unit (control unit).
Signal input with CAN communication line.
VHCL/S SEN·RR [km/h] or [mph] ×–×Wheel speed calculated by TCM.
Signal input with CAN communication line.
ENGINE SPEED [rpm] ×–×Engine speed calculated by ECM.
Signal input with CAN communication line.
THRTL POS SEN [V] ×–×Accelerator peda
l position (APP) sensor sig-
nal voltage is displayed.
Signal input with CAN communication line.
FLUID TEMP SE [V] ×–×Transfer fluid temperature sensor signal volt-
age is displayed.
BATTERY VOLT [V] ×–×Power supply voltage for transfer control unit.
2WD SWITCH [On/Off] ×–×4WD shift switch status is displayed.
AUTO SWITCH [On/Off] ×–×4WD shift switch status is displayed.
LOCK SWITCH [On/Off] ×–×4WD shift switch status is displayed.
(LOCK means 4H of 4WD shift switch.)
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DLN-20
< FUNCTION DIAGNOSIS >[ATX14B]
DIAGNOSIS SYSTEM (T
RANSFER CONTROL UNIT)
4L SW [On/Off] ×–×4WD shift switch status is displayed.
(4L means 4LO of 4WD shift switch.)
N POSI SW TF [On/Off] ×–×Neutral-4LO switch signal status is displayed.
ATP SWITCH [On/Off] ×–×ATP switch signal status is displayed.
WAIT DETCT SW [On/Off] ×–×Wait detection switch status is displayed.
LINE PRES SW [On/Off] ×–×Line pressure switch status is displayed.
CL PRES SW [On/Off] ×–×Clutch pressure switch status is displayed.
N POSI SW AT [On/Off] ×–×N position signal of transmission range switch
status is displayed.
Signal input with CAN communication line.
R POSI SW AT [On/Off] ×–×R position signal of transmission range switch
status is displayed.
Signal input with CAN communication line.
P POSI SW AT [On/Off] ×–×P position signal of transmission range switch
status is displayed.
Signal input with CAN communication line.
ABS OPER SW [On/Off] ×–×ABS operation signal status is displayed.
Signal input with CAN communication line.
VDC OPER SW [On/Off] ×–×VDC operation signal status is displayed.
Signal input with CAN communication line.
TCS OPER SW [On/Off] ×–×TCS operation signal status is displayed.
Signal input with CAN communication line.
THROTTLE POSI [0.0/8] –×× Thottle position status is displayed.
Signal input with CAN communication line.
4WD MODE [AUTO/LOCK/2WD/4L] – ××Control status of 4WD recognized by transfer
control unit. (AUTO, 4H, 2WD or 4LO)
VHCL/S COMP [km/h] or [mph] –×× Vehicle speed recognized by transfer control
unit.
COMP CL TORQ [kgm] –×× Calculated torque recognized by transfer con-
trol unit.
DUTY SOLENOID [%] –×× Control value of clutch pressure solenoid.
2-4WD SOL [On/Off] –×× Output condition to 2-4WD solenoid.
2-4WD SOL MON [On/Off] ––×Check signal for transfer control unit signal
output.
MOTOR RELAY [On/Off] –×× Transfer motor relay signal status is dis-
played.
MOTOR RELAY MON [On/Off] ––×Check signal for transfer control unit signal
ou
t

put.
4WD FAIL LAMP [On/Off] –×× Control status of 4WD warning lamp is dis-
played.
2WD IND [On/Off] ––×Control status of 4WD shift indicator lamp
(2WD indicator lamp) is displayed.
AUTO IND [On/Off] ––×Control status of 4WD shift indicator lamp
(2WD and AUTO indicator lamp) is displayed.
LOCK IND [On/Off] ––×Control status of 4WD shift indicator lamp
(2WD, AUTO and Lock indicator) is displayed.
4L IND [On/Off] ––×Control status of 4LO indicator lamp is dis-
played.
Monitored item (Unit)
Monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELEC-
TION FROM
MENU
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DIAGNOSIS SYSTEM (TRANSFER CONTROL UNIT)DLN-21
< FUNCTION DIAGNOSIS > [ATX14B]
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WORK SUPPORT
When there is no malfunction with transfer and 4WD sys tem, the following symptoms in AUTO mode may be
claimed by a customer: vibration when accelerating on a low µ road (snow-covered or icy road) or a slight
shock is felt at a few hertz as if it were being pushed lightly from behind.
It is possible to deal with these symptoms by changing the CLUTCH FORCE RELEASE LIMIT VALUE. How-
ever, be careful when changing the value because it may adversely affect driving performance.
Operation Procedure
1. Connect CONSULT-III.
2. Touch WORK SUPPORT.
3. Select from CLUTCH/F RLS LIM ADJ, screen of data monitor mode is displayed.
Clutch Force Release Limit Adjustment
1. Initial CLUTCH FORCE RELEASE LIMIT value 0.3 kgm appears under CONDITION SETTING on CON-
SULT-III display.
2. Touch 1.2 on the display.
3. Display changes to NOW ADJUSTING in a short time.
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 ADJUSTME NT COMPLETE will appear at the same time. Clutch force release
limit value setting is now complete.
ATP IND [On/Off] ––×Control status of ATP warning lamp is dis-
played.
SHIFT POS SW1 [On/Off] ×–×Actuator position switch 1 (Low) signal status
is displayed.
SHIFT POS SW2 [On/Off] ×–×Actuator position switch 2 (high) signal status
is displayed.
SHIFT ACT1 [On/Off] –×× Output condition to actuator motor (clockwise)
SHIFT AC MON1 [On/Off] ×–×Check signal for transfer control unit signal
output
SHIFT ACT2 [On/Off] –×× Output condition to actuator motor (counter-
clockwise)
SHIFT AC MON2 [On/Off] ×–×Check signal for transfer control unit signal
output
T/F F SPEED [km/h] or [mph] ×–×Displayed, but do not use.
A/T R SPEED [km/h] or [mph] ×–×Output shaft revolution signal (output speed
sensor) calculated by TCM.
Signal input with CAN communication line.
AT GEAR POSI [1/2/3/4/5] ×–×A/T actual gear position is displayed.
Monitored item (Unit)
Monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELEC-
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 th is value because the tight
corner braking symptom will get worse.
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DLN-22
< COMPONENT DIAGNOSIS >[ATX14B]
P1811 POWER SUPPLY CIRCUIT
FOR TRANSFER CONTROL UNIT
COMPONENT DIAGNOSIS
P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT
DescriptionINFOID:0000000005148775
Power supply to transfer control unit is abnormally low while driving.
DTC LogicINFOID:0000000005148776
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1811 detected?
YES >> Perform diagnosis procedure. Refer to DLN-22, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148777
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK POWER SUPPLY
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Check voltage between transfer control unit harness connector terminals and ground.
4. Turn ignition switch ON. (Do not start engine.)
5. Check voltage between transfer control unit harness connector terminals and ground.
DTC CONSULT-III Diagnostic item is detected when... Reference
[ P 1 8 11 ] B AT T E R Y V O LTA G E Power supply voltage for transfer control
unit is abnormally low while driving.Refer to
DLN-22
.
Connector Terminal Voltage (Approx.)
E142 16 - Ground
0V
22 - Ground
E143 29 - Ground
30 - Ground
Battery voltage
47 - Ground
WDIA0165E
Connector Terminal Voltage (Approx.)
E142 16 - Ground
Battery voltage
22 - Ground
E143 29 - Ground
30 - Ground
0V
47 - Ground Battery voltage
WDIA0166E
Revision: April 20092010 QX56

P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT
DLN-23
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Are the inspection results normal?
YES >> GO TO 2.
NO >> Check the following. If any items are damaged, repair or replace damaged parts. • 10A fuses No. 26 located in fuse and fusible link box and No. 59 located in the fuse and relaybox.
• 20A fuse No. 53 located in the IPDM E/R.
• Harness for short or open between battery and transfer control unit harness connector terminals
47.
• Harness for short or open between battery and transfer control unit harness connector terminal
29.
• Harness for short or open between battery and transfer shut off relay harness connector E69 terminal 1, and 5.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 2 and
transfer control unit harness connector terminal 30.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 3 and transfer control unit harness connector terminals 16 and 22.
• Battery and ignition switch.
• Transfer shut off relay. Refer to DLN-23, "
Component Inspection".
2.CHECK GROUND CIRCUIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check continuity between transfer control unit harness connec- tor E142 terminals 3, 6, E143 terminal 45 and ground.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 3.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
3.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are the inspection results normal?
YES >> GO TO 4.
NO >> Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.
4.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
Are the inspection results normal?
YES >> Inspection End.
NO >> Replace transfer control unit. Refer to DLN-130, "
Removal and Installation".
Component InspectionINFOID:0000000005148778
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Remove transfer shut off relay. Refer to DLN-16, "
Component Parts Location".
Continuity should exist.
SDIA2691E
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DLN-24
< COMPONENT DIAGNOSIS >[ATX14B]
P1811 POWER SUPPLY CIRCUIT
FOR TRANSFER CONTROL UNIT
3. Apply 12V direct current between transfer shut off relay termi-
nals 1 and 2.
4. Check continuity between relay terminals 3 and 5.
5. If inspection results are abnormal replace the transfer shut off relay.
Condition Continuity
12V direct current supply between terminals 1 and 2 Yes
OFF No
SCIA1245E
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P1802 – P1804, P1809 TRANSFER CONTROL UNIT
DLN-25
< COMPONENT DIAGNOSIS > [ATX14B]
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P1802 – P1804, P1809 TRANSFER CONTROL UNIT
DescriptionINFOID:0000000005148779
The transfer control unit controls the transfer control device which controls shifts between AUTO, 4H and 4LO
and between 2WD and 4WD. A DTC may se t when any of the following occur:
• Malfunction is detected in the memory (RAM) system of transfer control unit.
• Malfunction is detected in the memory (ROM) system of transfer control unit.
• Malfunction is detected in the memory (EEPROM) system of transfer control unit.
• AD converter system of transfer control unit is malfunctioning.
DTC LogicINFOID:0000000005148780
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Are DTC's P1802 - P1804 or P1809 detected?
YES >> Perform diagnosis procedure. Refer to DLN-25, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148781
1.INSPECTION START
Do you have CONSULT-III?
YES or NO
YES >> GO TO 2.
NO >> GO TO 3.
2.PERFORM SELF-DIAGNOSIS (WITH CONSULT-III)
With CONSULT-III
1. Turn ignition switch ON. (Do not start engine.)
2. Select SELF-DIAG RESULTS mode for ALL MODE AWD/4WD with CONSULT-III.
3. Touch ERASE.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Perform the self-diagnosis again.
Is the CONTROL UNIT 1 [P1802], CONTROL UNIT 2 [P1803], CONTROL UNIT 3 [P1804] or CONTROL
UNIT 4 [P1809] displayed?
YES >> Replace transfer control unit. Refer to DLN-130, "Removal and Installation".
NO >> Inspection End.
3.PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-III)
DTCCONSULT-III Diagnostic item is detected when... Reference
[P1802] CONTROL UNIT 1 Malfunction is detected in the memory
(RAM) system of transfer control unit.
Refer to DLN-25
.
[P1803] CONTROL UNIT 2
Malfunction is detected in the memory
(ROM) system of transfer control unit.
[P1804] CONTROL UNIT 3 Malfunction is detected in the memory
(EEPROM) system of transfer control
unit.
[P1809] CONTROL UNIT 4 AD converter system of transfer control
unit is malfunctioning.
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DLN-26
< COMPONENT DIAGNOSIS >[ATX14B]
P1802 – P1804, P1809 TRANSFER CONTROL UNIT

Without CONSULT-III
1. Perform the self-diagnosis and then erase self-diagnostic results. Refer to DLN-18, "CONSULT-III Func-
tion (ALL MODE AWD/4WD)".
2. Perform the self-diagnosis again.
Do the self-diagnostic results indicate AD converter?
YES >> Replace transfer control unit. Refer to DLN-130, "Removal and Installation".
NO >> Inspection End.
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P1807 VEHICLE SPEED SENSOR (A/T)DLN-27
< COMPONENT DIAGNOSIS > [ATX14B]
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P1807 VEHICLE SPEED SENSOR (A/T)
DescriptionINFOID:0000000005148782
The transmission control module (TCM) transmits the out put shaft revolution signal via CAN communication to
Transfer control unit. DTC P1807 will set when a malfunc tion is detected in the output shaft revolution signal
or an improper signal is input while driving.
DTC LogicINFOID:0000000005148783
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1807 detected?
YES >> Perform diagnosis procedure. Refer to DLN-27, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148784
1.CHECK DTC WITH TCM
Perform self-diagnosis with TCM. Refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
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 DLN-81, "
Reference Value".
Are the inspection results normal?
YES >> GO TO 3.
NO >> 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
Drive the vehicle and then perform self-diagnosis.
Are the inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with TCM again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1807] VHCL SPEED SEN·AT • Malfunction is detected in output shaft
revolution signal that is output from
TCM through CAN communication.
• Improper signal is input while driving. Refer to DLN-27
.
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DLN-28
< COMPONENT DIAGNOSIS >[ATX14B]
P1808 VEHICLE SPEED
SENSOR (ABS)
P1808 VEHICLE SPEED SENSOR (ABS)
DescriptionINFOID:0000000005148785
The ABS actuator and electric unit (control unit) tr ansmits a vehicle speed signal via CAN communication to
the transfer control unit. DTC P1808 sets when a malfunction is detected in the vehicle speed signal that is
output from the ABS actuator and elec tric unit (control unit) or an improper signal is input while driving.
DTC LogicINFOID:0000000005148786
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1808 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-28, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148787
1.CHECK DTC WITH ABS ACTUATOR AN D ELECTRIC UNIT (CONTROL UNIT)
Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to BRC-23, "
CONSULT-III
Function (ABS)".
Is any malfunction detec ted 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 DLN-81, "
Reference Value".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Check transfer control unit pin terminals fo r 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.
Are the inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with ABS actuator and electric unit (control unit) again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1808] VHCL SPEED SEN·ABS • Malfunction is detected in vehicle
speed signal that is output from ABS
actuator and electric unit (control unit)
through CAN communication.
• Improper signal is input while driving. Refer to
DLN-28
.
Revision: April 20092010 QX56