2005 INFINITI QX4 brake

TROUBLE DIAGNOSIS FOR SYSTEM
TF-59
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TF
Revision: October 20052005 QX56
Neutral-4LO SwitchEDS002I8
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.Monitored item Content Condition Display value
N POSI SW TF [ON/
OFF]Condition of neutral-4LO
switch

Vehicle stopped

Engine running

A/T selector lever “N”
position

Brake pedal depressed4WD shift switch: 2WD,
AUTO or 4HOFF
4WD shift switch: 4H to
4LO (While actuator
motor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON
Te r m i n a lWire
colorItem Condition Data (Approx.)
25 V Neutral-4LO switch

Vehicle stopped

Engine running

A/T selector
lever “N” position

Brake pedal
depressed4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)Battery volt-
age → 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.)0V → Battery
voltage
4WD shift switch: 4LO 0V

TF-60
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK 4LO POSITION SWITCH 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 “N POSI SW TF”.
Without CONSULT-II
1. Start engine.
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 NEUTRAL-4LO SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the neutral-4LO switch harness connector.
3. Check continuity between transfer control unit harness connec-
tor E143 terminal 25 (V) and neutral-4LO switch harness con-
nector F60 terminal 13 (V).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
Condition Display value

Vehicle stopped

Engine running

A/T selector lever “N” position

Brake pedal depressed4WD shift switch: 2WD,
AUTO or 4HOFF
4WD shift switch: 4H to
4LO (While actuator
motor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON
SDIA2692E
ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
E143 25 (V) -
Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch:
2WD, AUTO or 4HBattery
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
SDIA2693E
Continuity should exist.
SDIA2694E

TF-62
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
COMPONENT INSPECTION
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect neutral-4LO switch harness connector.
3. Remove neutral-4LO switch. Refer to TF-22, "
Location of Electrical Parts" .
4. Push and release neutral-4LO switch and check continuity
between neutral-4LO switch terminals 12 and 13.
5. If NG, replace the neutral-4LO switch. Refer to TF-22, "
Location
of Electrical Parts" .
4WD Shift SwitchEDS0 02 I9
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.Terminal Condition Continuity
12 - 13Push neutral-4LO switch Yes
Release neutral-4LO switch No
SDIA2696E
Monitored item [Unit] Content Condition Display value
2WD SWITCH [ON/
OFF]Input condition from 4WD
shift switch4WD shift switch: 2WD ON
4WD shift switch: AUTO, 4H or 4LO OFF
AUTO SWITCH [ON/
OFF]Input condition from 4WD
shift switch4WD shift switch: AUTO ON
4WD shift switch: 2WD, 4H or 4LO OFF
LOCK SWITCH [ON/
OFF]Input condition from 4WD
shift switch4WD shift switch: 4H ON
4WD shift switch: 2WD, AUTO or 4LO OFF
4L SWITCH [ON/OFF]Input condition from 4WD
shift switch4WD shift switch: 4LO ON
4WD shift switch: 2WD, AUTO or 4H OFF
4WD MODE [AUTO/
LOCK/2WD/4L]Control status of 4WD
(Output condition of 4WD
shift indicator lamp and
4LO indicator lamp)

Vehicle stopped

Engine running

A/T selector lever “N”
position

Brake pedal depressed4WD shift switch: 2WD 2WD
4WD shift switch: AUTO AUTO
4WD shift switch: 4H LOCK
4WD shift switch: 4LO 4L
Te r m i n a lWire
colorItem Condition Data (Approx.)
9G/W4WD shift switch
(2WD)Ignition switch: ON4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V
18 O4WD shift switch
(4H)Ignition switch: ON4WD shift switch: 4H Battery voltage
4WD shift switch: 2WD, AUTO or 4LO 0V
23 R4WD shift switch
(4LO)Ignition switch: ON4WD shift switch: 4LO Battery voltage
4WD shift switch: 2WD, AUTO or 4H 0V
24 LG/R4WD shift switch
(AUTO)Ignition switch: ON4WD shift switch: AUTO Battery voltage
4WD shift switch: 2WD, 4H or 4LO 0V

TF-66
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
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.
4. If NG, replace the 4WD shift switch.
Wait Detection SwitchEDS002IA
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.Connector Terminal Condition Continuity
M1411 - 24WD shift switch: 2WD Yes
4WD shift switch: AUTO, 4H and
4LONo
1 - 34WD shift switch: AUTO Yes
4WD shift switch: 2WD, 4H and
4LONo
1 - 44WD shift switch: 2WD No
4WD shift switch: AUTO, 4H and
4LOYe s
1 - 54WD shift switch: 4H Yes
4WD shift switch: 2WD, AUTO,
and 4LONo
1 - 64WD shift switch: 4LO Yes
4WD shift switch: 2WD, AUTO
and 4HNo
WDIA0205E
Monitored item Content Condition Display value
WAIT DETCT SW [ON/
OFF]Condition of wait detection
switch

Vehicle stopped

Engine running

A/T selector lever “N”
position

Brake pedal depressed4WD shift switch: 2WD,
AUTO or 4HOFF
4WD shift switch: 4H to
4LO (While actuator
motor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON
Te r m i n a lWire
colorItem Condition Data (Approx.)
43 G/Y Wait detection switch

Vehicle stopped

Engine running

A/T selector
lever “N” position

Brake pedal
depressed4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)Battery volt-
age → 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.)0V → Battery
voltage
4WD shift switch: 4LO 0V

TROUBLE DIAGNOSIS FOR SYSTEM
TF-67
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TF
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK WAIT DETECTION SWITCH 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 “WAIT DETCT SW”.
Without CONSULT-II
1. Start engine.
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 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 (G/Y) and wait detection switch harness
connector F59 terminal 10 (G/Y).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
Condition Display value

Vehicle stopped

Engine running

A/T selector lever “N” position

Brake pedal depressed4WD shift switch: 2WD, AUTO
or 4HOFF
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
PDIA0221E
ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
E14343 (G/Y)
- Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch:
2WD, AUTO or 4HBattery
voltage
4WD shift switch: 4H
to 4LO (While actua-
tor 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
SDIA2701E
Continuity should exist.
SDIA2702E

TF-70
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
Actuator MotorEDS002IC
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.Monitored item Content Condition Display value
SHIFT ACT1 [ON/OFF]Output condition to
actuator motor (High)

Vehicle stopped

Engine running

A/T selector lever “N”
position

Brake pedal depressed4WD shift switch: 4H to
4LO (“Wait” function is
operating.)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
operating.)ON
Except the above OFF
SHIFT ACT2 [ON/OFF]Output condition to
actuator motor (Low)

Vehicle stopped

Engine running

A/T selector lever “N”
position

Brake pedal depressed4WD shift switch: 4LO to
4H (“Wait” function is
operating.)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
operating.)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
lever “N” position

Brake pedal
depressed4WD 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
lever “N” position

Brake pedal
depressed4WD 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
lever “N” position

Brake pedal
depressed4WD 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
lever “N” position

Brake pedal
depressed4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V

TROUBLE DIAGNOSIS FOR SYSTEM
TF-71
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F
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MA
B
TF
Revision: October 20052005 QX56
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.
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 operat-
ing.)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 operat-
ing.)ON
Except the above OFF
ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
E1424 (Y/L) -
Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch: 4H
to 4LO (“Wait” function
is operating.)Battery
voltage
Except the above 0V
13 (G/B)
- Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch: 4LO
to 4H (“Wait” function
is operating.)Battery
voltage
Except the above 0V
PDIA0223E
SDIA2705E

TF-72
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
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 (R), transfer shift low relay harness connector
E47 terminal 5 (R) 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 (R), transfer shift low relay harness connector
E47 terminal 5 (R) 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-4, "POWER SUPPLY ROUTING
CIRCUIT" .

Harness for short or open between battery, transfer shift high relay harness connector terminal
5 and transfer shift low relay harness connector terminal 5.
E14333 (R/L) -
Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch: 4H
to 4LO (“Wait” function
is operating.)Battery
voltage
Except the above 0V
42 (P/G)
- Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch: 4LO
to 4H (“Wait” function
is operating.)Battery
voltage
Except the above 0V ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
Connector Terminal (Wire color) Voltage (Approx.)
E46 5 (R) - Ground
Battery voltage
E47 5 (R) - Ground
SDIA2707E
Connector Terminal (Wire color) Voltage (Approx.)
E46 5 (R) - Ground
Battery voltage
E47 5 (R) - Ground
SDIA2706E