2007 INFINITI QX56 engine

TF-64
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
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 TCM again. Refer to AT-83, "
CONSULT-II Function (A/T)".
Actuator MotorINFOID:0000000003532537
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.
Monitored item Content Condition Display value
SHIFT ACT1 [ON/OFF]Output condition to ac-
tuator motor (High)• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 4H to
4LO (“Wait” function is op-
erating.)ON
Except the above OFF
SHIFT AC MON1 [ON/OFF]Check signal for trans-
fer control unit signal
output• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 4H to
4LO (“Wait” function is op-
erating.)ON
Except the above OFF
SHIFT ACT2 [ON/OFF]Output condition to ac-
tuator motor (Low)• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 4LO to
4H (“Wait” function is op-
erating.)ON
Except the above OFF
SHIFT AC MON2 [ON/OFF]Check signal for trans-
fer control unit signal
output• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 4LO to
4H (“Wait” function is op-
erating.)ON
Except the above OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
4 Y/L Transfer shift high relay• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
13 G/B Transfer shift low relay• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
33 R/LTransfer shift high relay moni-
tor• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V

TROUBLE DIAGNOSIS FOR SYSTEM
TF-65
< SERVICE INFORMATION >
C
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F
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MA
B
TF
N
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CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
DIAGNOSTIC PROCEDURE
1.CHECK ACTUATOR MOTOR SIGNAL
With CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Read out the value of “SHIFT ACT1”, “SHIFT AC MON1”,
“SHIFT ACT2” and “SHIFT AC MON2”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
42 P/GTransfer shift low relay moni-
tor• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V Te r m i n a lWire
colorItem Condition Data (Approx.)
Monitored
itemConditionDisplay
value
SHIFT ACT1• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 4H
to 4LO (“Wait” func-
tion is operating.)ON
Except the above OFF
SHIFT AC
MON1• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 4H
to 4LO (“Wait” func-
tion is operating.)ON
Except the above OFF
SHIFT ACT2• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch:
4LO to 4H (“Wait”
function is operating.)ON
Except the above OFF
SHIFT AC
MON2• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch:
4LO to 4H (“Wait”
function is operating.)ON
Except the above OFF
PDIA0223E
SDIA2705E

TF-66
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
OK or NG
OK >> GO TO 7.
NG >> 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.
4. Turn ignition switch “ON”. (Do not start engine.)
5. 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.
OK or NG
OK >> GO TO 3.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.
• 20A fuse [No. 57, located in the fuse block (J/B)]. Refer to PG-3
.
Connector Terminal ConditionVoltage
(Approx.)
E1424 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD 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-
pressed4WD shift switch: 4LO
to 4H (“Wait” function
is operating.)Battery
voltage
Except the above 0V
E14333 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD 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-
pressed4WD shift switch: 4LO
to 4H (“Wait” function
is operating.)Battery
voltage
Except the above 0V
Connector Terminal Voltage (Approx.)
E46 5 - Ground
Battery voltage
E47 5 - Ground
WDIA0310E
Connector Terminal Voltage (Approx.)
E46 5 - Ground
Battery voltage
E47 5 - Ground
WDIA0311E

TF-70
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
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 ACTUATOR POSITION SWITCH 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 “SHIFT POS SW1” and “SHIFT POS
SW2”.
Without CONSULT-II
1. Start engine.
Monitored item [Unit] Content Condition Display value
SHIFT POS SW1 [ON/
OFF]Condition of actuator posi-
tion switch 1
(Low)• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 4LO ON
4WD shift switch: 2WD,
AUTO or 4HOFF
SHIFT POS SW2 [ON/
OFF]Condition of actuator posi-
tion switch 2
(High)• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 4H,
AUTO or 2WDON
4WD shift switch: 4LO OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
27 W/LActuator position switch 2
(High)• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4H, AUTO or 2WD 0V
4WD shift switch: 4LO Battery voltage
44 LG/BActuator position switch 1
(Low)• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4LO 0V
4WD shift switch: 2WD, AUTO or 4H Battery voltage
Monitored item Condition Display value
SHIFT POS SW1• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4LO ON
4WD shift switch:
2WD, AUTO or 4HOFF
SHIFT POS SW2• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4H,
AUTO or 2WDON
4WD shift switch: 4LO OFF
SDIA2714E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-71
< SERVICE INFORMATION >
C
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B
TF
N
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2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND ACTUATOR POSITION SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the transfer control device (actuator position
switch) harness connector.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E143 terminal 27 and
transfer control device (actuator position switch) harness con-
nector F58 terminal 23.
- Transfer control unit harness connector E143 terminal 44 and
transfer control device (actuator position switch) harness con-
nector F58 terminal 20.
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 GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control device (actuator position switch) harness connector.
3. Check continuity between transfer control device (actuator posi-
tion switch) harness connector F58 terminal 22 and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
4.CHECK ACTUATOR POSITION SWITCH
1. Remove transfer control device. Refer to TF-115, "
Removal and Installation".
Connector Terminal ConditionVoltage
(Approx.)
E14327 -
Ground• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4H,
AUTO or 2WD0V
4WD shift switch: 4LOBattery
voltage
44 -
Ground• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4LO 0V
4WD shift switch:
2WD, AUTO or 4HBattery
voltage
SDIA2715E
Continuity should exist.
SDIA2716E
Continuity should exist.
SDIA2717E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-73
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
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 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
terminal and ground.
Monitored item [Unit] Content Condition Display value
SHIFT AC MON1 [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: 4H to
4LO (“Wait” function is op-
erating.)ON
Except the above OFF
SHIFT AC MON2 [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: 4LO to
4H (“Wait” function is oper-
ating.)ON
Except the above OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
16 Y/R Power supplyIgnition switch: ON Battery voltage
Ignition switch: OFF 0V
22 Y/R Power supplyIgnition switch: ON Battery voltage
Ignition switch: OFF 0V
30 SB Shut off relayIgnition switch: ON 0V
Ignition switch: OFF Battery voltage
33 R/LTransfer shift high relay moni-
tor• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
42 P/GTransfer shift low relay moni-
tor• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
Connector Terminal Voltage (Approx.)
E14216 - Ground
0V
22 - Ground
E143 30 - Ground Battery voltage
SDIA2834E

TF-74
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 2.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.
• 10A fuse No. 26 located in the fuse and fusible link box. Refer to PG-3
.
• Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 1.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 2 and
transfer control unit harness connector E143 terminal 30.
• Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 3.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 5 and
transfer control unit harness connector E142 terminal 22.
• Transfer shut off relay. Refer to TF-51, "
Power Supply Circuit for Transfer Control Unit".
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.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3.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. Refer to TF-22, "
Location of Electrical Parts".
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.
Connector Terminal Voltage (Approx.)
E14216 - Ground
Battery voltage
22 - Ground
E143 30 - Ground 0V
SDIA2835E
Continuity should exist.
SDIA2691E
Connector Terminal Voltage (Approx.)
E46 5 - Ground
Battery voltage
E47 5 - Ground
WDIA0310E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-75
< SERVICE INFORMATION >
C
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H
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B
TF
N
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4. Turn ignition switch “ON”. (Do not start engine.)
5. 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.
OK or NG
OK >> GO TO 4.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.
• 20A fuse No. 57 located in the fuse and relay box. Refer to PG-3
.
• Harness for short or open between battery, transfer shift high relay harness connector E46 ter-
minal 5 and transfer shift low relay harness connector E47 terminal 5.
4.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND TRANSFER SHIFT RELAY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and transfer control device (actuator motor) harness
connector.
3. Remove transfer shift high relay and transfer shift low relay. Refer to TF-22, "
Location of Electrical Parts".
4. Check continuity between the following terminals.
- Transfer control unit harness connector E143 terminal 33 (A)
and transfer shift high relay harness connector E46 terminal 3
(B).
- Transfer control unit harness connector E143 terminal 42 (A)
and transfer shift low relay harness connector E47 terminal 3
(C).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5.CHECK TRANSFER SHIFT RELAY GROUND 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 continuity between transfer shift high relay harness con-
nector E46 terminals 2, 4 (A), transfer shift low relay harness
connector E47 terminals 2, 4 (B) and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
6.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-1 >> With CONSULT-II: GO TO 7.
OK-2 >> Without CONSULT-II: 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.
Connector Terminal Voltage (Approx.)
E46 5 - Ground
Battery voltage
E47 5 - Ground
WDIA0311E
Continuity should exist.
WDIA0315E
Continuity should exist.
WDIA0312E