INFINITI QX56 2008 Factory Service Manual

P1813 4WD SHIFT SWITCHDLN-31
< COMPONENT DIAGNOSIS > [ATX14B]
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P1813 4WD SHIFT SWITCH
DescriptionINFOID:0000000001737118
The 4WD shift switch allows the driver to select AUTO, 2WD or 4WD and 4H or 4LO. DTC P1813 will set if
more than two switch inputs are simultaneously detected by the transfer control unit due to a short circuit in the
4WD shift switch.
DTC LogicINFOID:0000000001737119
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1813 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-31, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737120
1.CHECK 4WD SHIFT SWITCH SIGNAL
With CONSULT-III
1. Turn ignition switch ON. (Do not start engine.)
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out ON/OFF switching action of the 2WD SWITCH, AUTO SWITCH, LOCK SWITCH, 4L SW with
operating 4WD shift switch.
Without CONSULT-III
1. Turn ignition switch ON. (Do not start engine.)
2. Check voltage between transfer control unit harness connector
terminals and ground.
Are inspection results normal?
YES >> GO TO 5.
NO >> GO TO 2.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1813] 4WD MODE SW More than two switch inputs are simulta-
neously detected due to short circuit of
4WD shift switch.Refer to DLN-31
.
Connector Terminal
ConditionVoltage (Ap-
prox.)
E142 9 - ground
4WD shift switch: 2WD
Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V
18 - ground 4WD shift switch: 4H
Battery voltage
4WD shift switch: 2WD, AUTO or
4LO 0V
23 - ground 4WD shift switch: 4LO
Battery voltage
4WD shift switch: 2WD, AUTO or 4H 0V
24 - ground 4WD shift switch: AUTO
Battery voltage
4WD shift switch: 2WD, 4H or 4LO 0V
WDIA0148E
Revision: March 2010 2008 QX56

DLN-32
< COMPONENT DIAGNOSIS >[ATX14B]
P1813 4WD SHIFT SWITCH
2.CHECK 4WD SHIFT SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect 4WD shift switch harness connector.
3. Check voltage between 4WD shift switch harness connector ter- minal 1 and ground.
4. Turn ignition switch ON. (Do not start engine.)
5. Check voltage between 4WD shift switch harness connector ter- minal 1 and ground.
Are inspection results normal?
YES >> GO TO 3.
NO >> Refer to DLN-22, "
Diagnosis Procedure".
3.CHECK HARNESS BETWEEN 4WD SHIFT SWITCH AND TRANSFER CONTROL UNIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the 4WD shift switch harness connector.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 terminal 9 and 4WD shift switch harness connector M141 terminal 2.
- Transfer control unit harness connector E142 terminal 18 and 4WD shift switch harness connector M141 terminal 5.
- Transfer control unit harness connector E142 terminal 23 and 4WD shift switch harness connector M141 terminal 6.
- Transfer control unit harness connector E142 terminal 24 and
4WD shift switch harness connector M141 terminal 3.
Also check harness for short to ground and short to power.
Are inspection results normal?
YES >> GO TO 4.
NO >> Check the following. If any items are damaged, repair or replace damaged parts. • Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 3.
• Power supply circuit for transfer control unit. Refer to DLN-22, "
Diagnosis Procedure".
4.CHECK 4WD SHIFT SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect 4WD shift switch harness connector.
Connector Terminal Voltage (Approx.)
M141 1 - Ground 0V
SDIA2383E
ConnectorTerminal Voltage (Approx.)
M141 1 - Ground Battery voltage
PDIA0210E
Continuity should exist.SDIA2699E
Revision: March 2010 2008 QX56

P1813 4WD SHIFT SWITCHDLN-33
< COMPONENT DIAGNOSIS > [ATX14B]
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3. Operate 4WD shift switch and check continuity between 4WD shift switch terminals.
Are inspection results normal?
YES >> GO TO 5.
NO >> Replace 4WD shift switch.
5.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-80, "
Reference Value".
Are inspection results normal?
YES >> GO TO 6.
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.
6.CHECK DTC
Drive the vehicle and then perform self-diagnosis.
Are inspection results normal?
YES >> Inspection End.
NO >> Replace transfer control unit. Refer to DLN-128, "
Removal and Installation".
Component InspectionINFOID:0000000001737121
COMPONENT INSPECTION
1. Turn ignition switch OFF. (Stay for at least 5 second.)
2. Disconnect 4WD shift switch harness connector.
3. Operate 4WD shift switch and check continuity between 4WD
shift switch terminals.
Terminal ConditionContinuity
1 - 2 4WD shift switch: 2WD
Yes
4WD shift switch: AUTO, 4H and
4LO No
1 - 3 4WD shift switch: AUTO
Yes
4WD shift switch: 2WD, 4H and
4LO No
1 - 4 4WD shift switch: 2WD
No
4WD shift switch: AUTO, 4H and
4LO Ye s
1 - 5 4WD shift switch: 4H
Yes
4WD shift switch: 2WD, AUTO,
and 4LO No
1 - 6 4WD shift switch: 4LO
Yes
4WD shift switch: 2WD, AUTO and
4H No
WDIA0205E
Terminal
ConditionContinuity
1 - 2 4WD shift switch: 2WD
Yes
4WD shift switch: AUTO, 4H and
4LO No
1 - 3 4WD shift switch: AUTO
Yes
4WD shift switch: 2WD, 4H and
4LO No
WDIA0205E
Revision: March 2010
2008 QX56

DLN-34
< COMPONENT DIAGNOSIS >[ATX14B]
P1813 4WD SHIFT SWITCH
4. If the inspection results are abnormal replace the 4WD shift switch.
1 - 44WD shift switch: 2WD No
4WD shift switch: AUTO, 4H and
4LO
Ye s
1 - 5 4WD shift switch: 4H
Yes
4WD shift switch: 2WD, AUTO,
and 4LO No
1 - 6 4WD shift switch: 4LO
Yes
4WD shift switch: 2WD, AUTO and
4H No
Terminal
ConditionContinuity
Revision: March 2010 2008 QX56

P1814 WAIT DETECTION SWITCHDLN-35
< COMPONENT DIAGNOSIS > [ATX14B]
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P1814 WAIT DETECTION SWITCH
DescriptionINFOID:0000000001737122
The wait detection switch detects if the transfer case is in 4WD. DTC P1814 will set if an improper signal from
the wait detection switch is input due to open or short circuit.
DTC LogicINFOID:0000000001737123
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1814 detected?
YES >> Perform diagnosis procedure. Refer to DLN-35, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737124
1.CHECK WAIT DETECTION SWITCH SIGNAL
With CONSULT-III
1. Start engine.
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out the value of WAIT DETCT SW.
Without CONSULT-III
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1814] 4WD DETECT SWITCH Improper signal from wait detection
switch is input due to open or short cir-
cuit.
Refer to DLN-35
.
Condition
Display value
• Vehicle stopped
• Engine running
• A/T selector lever N position
• Brake pedal depressed 4WD shift switch: 2WD, AUTO
or 4H
OFF
4WD shift switch: 4H to 4LO
(While actuator motor is operat-
ing.) OFF
→ ON
4WD shift switch: 4LO to 4H
(While actuator motor is operat-
ing.) ON
→ OFF
4WD shift switch: 4LO ON
SDIA2701E
Revision: March 2010 2008 QX56

DLN-36
< COMPONENT DIAGNOSIS >[ATX14B]
P1814 WAIT DETECTION SWITCH
Are inspection results normal?
YES >> GO TO 5.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSFER CONT
ROL UNIT AND WAIT DETECTION SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the wait detection switch harness connector.
3. Check continuity between transfer control unit harness connec- tor E143 terminal 43 and wait detection switch harness connec-
tor F59 terminal 10.
Also check harness for short to ground and short to power.
Are inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK GROUND CIRCUIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect wait detection switch harness connector.
3. Check continuity between wait detection switch harness con- nector F59 terminal 11 and ground.
Also check harness for short to ground and short to power.
Are inspection results normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK WAIT DETECTION SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect wait detection switch harness connector.
3. Remove wait detection switch. Refer to DLN-16, "
Component Parts Location".
Connector TerminalConditionVoltage
(Approx.)
E143 43 -
Ground • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de- pressed 4WD shift switch:
2WD, AUTO or 4H
Battery
voltage
4WD shift switch: 4H to
4LO (While actuator
motor is operating.) Battery
voltage
→ 0V
4WD shift switch: 4LO
to 4H (While actuator
motor is operating.) 0V
→
Battery
voltage
4WD shift switch: 4LO 0V
Continuity should exist.
SDIA2702E
Continuity should exist.
SDIA2703E
Revision: March 2010 2008 QX56

P1814 WAIT DETECTION SWITCHDLN-37
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4. Push and release wait detection switch and check continuity between wait detection switch terminals 10 and 11.
Are inspection results normal?
YES >> GO TO 5.
NO >> Replace wait detection switch.
5.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-80, "
Reference Value".
Are inspection results normal?
YES >> GO TO 6.
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.
6.CHECK DTC
Drive the vehicle and then perform self-diagnosis.
Are inspection results normal?
YES >> Inspection End.
NO >> Replace transfer control unit. Refer to DLN-128, "
Removal and Installation".
Component InspectionINFOID:0000000001737125
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect wait detection switch harness connector.
3. Remove wait detection switch. Refer to DLN-16, "
Component Parts Location".
4. Push and release wait detection switch and check continuity between wait detection switch terminals 10 and 11.
5. If the inspection results are abnormal replace the wait detection switch.
Terminal Condition Continuity
10 - 11 Push wait detection switch
Yes
Release wait detection switch No
SDIA2704E
TerminalCondition Continuity
10 - 11 Push wait detection switch
Yes
Release wait detection switch No
SDIA2704E
Revision: March 2010 2008 QX56

DLN-38
< COMPONENT DIAGNOSIS >[ATX14B]
P1816 PNP SWITCH
P1816 PNP SWITCH
DescriptionINFOID:0000000001737126
The A/T transmission range switch transmits the A/T pos
ition indicator signal (transmission range switch sig-
nal) via CAN communication to the transfer control uni t. DTC P1816 will set when the A/T transmission range
switch signal is malfunctioning or there is a communication error.
DTC LogicINFOID:0000000001737127
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1816 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-38, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737128
1.CHECK DTC WITH TCM
Perform self-diagnosis with TCM. Refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
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-80, "
Reference Value".
Are 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
Drive the vehicle and then perform self-diagnosis.
Are inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with TCM again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1816] PNP SW/CIRC When A/T transmission range switch
signal is malfunction or communication
error between the control units.Refer to
DLN-38
.
Revision: March 2010 2008 QX56

P1817 ACTUATOR MOTORDLN-39
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P1817 ACTUATOR MOTOR
DescriptionINFOID:0000000001737129
The actuator motor receives signals from the transfer c ontrol unit and controls shift rods which shift the trans-
fer case. DTC P1817 will set when any of the following occur:
• Motor does not operate properly due to open or short circuit in actuator motor.
• Malfunction is detected in the actuator motor. (W hen 4WD shift switch is operated and actuator motor does
not operate)
• Malfunction is detected in transfer shift high relay or transfer shift low relay.
DTC LogicINFOID:0000000001737130
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1817 detected?
YES >> Perform diagnosis procedure. Refer to DLN-39, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737131
1.CHECK ACTUATOR MOTOR SIGNAL
With CONSULT-III
1. Start engine.
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out the value of SHIFT ACT1, SHIFT AC MON1, SHIFT ACT2 and SHIFT AC MON2.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1817] SHIFT ACTUATOR • Motor does not operate properly due
to open or short circuit in actuator mo-
tor.
• Malfunction is detected in the actuator motor. (When 4WD shift switch is op-
erated and actuator motor is not oper-
ated)
• Malfunction is detected in transfer shift
high relay and transfer shift low relay. Refer to DLN-39
.
Monitored
item Condition Display
value
SHIFT ACT1 • Vehicle stopped
• Engine running
• A/T selector lever N position
• Brake pedal depressed 4WD shift switch: 4H
to 4LO (Wait function
is operating.)
ON
Except the above OFF
SHIFT AC
MON1 • Vehicle stopped
• Engine running
• A/T selector lever N position
• Brake pedal depressed 4WD shift switch: 4H
to 4LO (Wait function
is operating.)
ON
Except the above OFF
SHIFT ACT2 • Vehicle stopped
• Engine running
• A/T selector lever N position
• Brake pedal depressed 4WD shift switch:
4LO to 4H (Wait func-
tion is operating.)
ON
Except the above OFF
Revision: March 2010 2008 QX56

DLN-40
< COMPONENT DIAGNOSIS >[ATX14B]
P1817 ACTUATOR MOTOR

Without CONSULT-III
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
Are the inspection results normal?
YES >> GO TO 7.
NO >> GO TO 2.
2.CHECK ACTUATOR MOTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Remove transfer shift high relay and transfer shift low relay.
3. Check voltage between transfer shift high relay harness connec- tor E46 terminal 5 (A), transfer shift low relay harness connector
E47 terminal 5 (B) and ground.
SHIFT AC
MON2 • Vehicle stopped
• Engine running
• A/T selector lever N position
• Brake pedal depressed 4WD shift switch:
4LO to 4H (Wait func-
tion is operating.)
ON
Except the above OFF
Connector Terminal ConditionVoltage
(Approx.)
E142 4 -
Ground • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de-
pressed 4WD shift switch: 4H to
4LO (Wait function is
operating.)
Battery
voltage
Except the above 0V
13 -
Ground • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de- pressed 4WD shift switch: 4LO
to 4H (Wait function is
operating.)
Battery
voltage
Except the above 0V
E143 33 -
Ground • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de- pressed 4WD shift switch: 4H to
4LO (Wait function is
operating.)
Battery
voltage
Except the above 0V
42 -
Ground • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de-
pressed 4WD shift switch: 4LO
to 4H (Wait function is
operating.)
Battery
voltage
Except the above 0V
Monitored
item Condition Display
value
SDIA2705E
Connector Terminal Voltage (Approx.)
A: E46 5 - Ground
Battery voltage
B: E47 5 - Ground
WDIA0310E
Revision: March 2010 2008 QX56