2006 INFINITI QX56 air condition

TROUBLE DIAGNOSIS FOR SYSTEMTF-93
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Revision: November 2009 2006 QX56
3. CHECK 4WD SHIFT SWITCH SIGNAL
1. Turn ignition switch “ON”. (Do not start engine.)
2. Check voltage between transfer control unit harness connector terminals and ground.
OK or NG
OK >> GO TO 4.
NG >> Check 4WD shift switch. Refer to TF-66, "
COMPONENT INSPECTION" .
4. CHECK HARNESS BETWEEN 4WD SHIFT SWITCH AND TRANSFER TERMINAL CORD ASSEMBLY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect 4WD shift switch harness connector and transfer terminal cord assembly harness connector.
3. Check continuity between 4WD shift switch harness connector M141 terminal 4 and transfer terminal cord assembly harness
connector F56 terminal 5.
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 HARNESS BETWEEN TRANSFER CONTROL UNIT AND TRANSFER TERMINAL CORD
ASSEMBLY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and transfer terminal cord assembly harness connec- tor.
3. Check continuity between transfer control unit harness connec- tor E142 terminal 1 and transfer terminal cord assembly harness
connector F56 terminal 4.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
Connector Terminal ConditionVoltage
(Approx.)
M141 4 - ground 4WD shift switch: AUTO, 4H or 4LO Battery voltage
4WD shift switch: 2WD
0V
SDIA2729E
Continuity should exist.
SDIA2731E
Continuity should exist.
SDIA2732E

TROUBLE DIAGNOSIS FOR SYSTEMTF-99
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Revision: November 2009 2006 QX56
2. CHECK TRANSFER MOTOR RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Disconnect transfer motor relay.
4. Check voltage between transfer motor relay harness connector terminals and ground.
5. Turn ignition switch “ON”. (Do not start engine.)
6. Check voltage between transfer motor relay harness connector terminals 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. 58 located in the fuse and relay box. Refer to PG-4, "POWER SUPPLY ROUTING
CIRCUIT" .

10A fuse No. 26 located in the fuse and fusible link box. Refer to PG-4, "POWER SUPPLY
ROUTING CIRCUIT"

Harness for short or open between battery and transfer motor relay harness connector E154
terminal 5.

Harness for short or open between transfer shut off relay harness connector E69 terminal 5
and transfer motor relay harness connector E153 terminal 2.

Battery and ignition switch. Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT" .
3. CHECK TRANSFER MOTOR RELAY
1. Turn ignition switch “OFF”.
2. Remove transfer motor relay. Refer to TF-22, "
Location of Electrical Parts" .
3. Apply 12V direct current between transfer motor relay terminals 1 and 2.
4. Check continuity between relay terminals 3 and 5.
OK or NG
OK >> GO TO 4.
NG >> Replace the transfer motor relay.
Connector Terminal Voltage (Approx.)
E153 2 - Ground 0V
E154 5 - Ground Battery voltage
WDIA0169E
ConnectorTerminal Voltage (Approx.)
E153 2 - Ground
Battery voltage
E154 5 - Ground
WDIA0170E
Condition Continuity
12V direct current supply between terminals 1 and 2 Yes
OFF No
LDIA0098E

TROUBLE DIAGNOSIS FOR SYSTEMTF-103
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Revision: November 2009 2006 QX56
DIAGNOSTIC PROCEDURE
1. CHECK TRANSFER FLUID TEMPERATURE SENSOR 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 “FLUID TEMP SE”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector terminals and ground.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND TRANSFER TERMINAL CORD
ASSEMBLY 1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and transfer terminal cord assembly harness connec- tor.
3. Check continuity between the following terminals.
–Transfer control unit harness connector E143 terminal 28 and
transfer terminal cord assembly harness connector F56 terminal
3.
–Transfer control unit harness connector E143 terminal 31 and
transfer terminal cord assembly harness connector F56 terminal
2.
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
(Approx.)
Transfer fluid temperature approx. 20 - 80 °C (68 - 176°F) 1.1 - 0.3V
SDIA2741E
Connector Terminal ConditionData
(Approx.)
E143 28 -
Ground Always
0V
31 -
Ground Ignition switch:
ON Transfer fluid temperature
approx. 20
°C (68°F) 1.1V
Transfer fluid temperature
approx. 80 °C (176°F) 0.3V
SDIA2742E
Continuity should exist.
SDIA2743E

TF-106
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: November 20092006 QX56
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.
3. Read out ON/OFF switching action of the “CL PRES SW ” while
operating 4WD shift switch.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector terminals and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND CLUTCH PRESSURE SWITCH
1. Turn ignition switch “ OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the transfer terminal cord assembly harness con- nector.
3. Check continuity between transfer control unit harness connec- tor E143 terminal 34 and transfer terminal cord assembly har-
ness connector F56 terminal 7
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

Ignition switch: ON

A/T selector lever “D ”
position 4WD shift switch: AUTO or 4H
(
“ Wait ” function is not operating.) ON
Ignition switch: ON 4WD shift switch: 2WD (
“Wait ”
function is not operating.) OFF
Connector Terminal ConditionVoltage
(Approx.)
E143 34 -
Ground

Ignition switch: ON

A/T selector lever
“ D ” position 4WD shift switch:
AUTO or 4H
(
“ Wait ” function is
not operating.) 0V
Ignition switch: ON 4WD shift switch:
2WD (
“Wait ” func-
tion is not operat-
ing.) Battery
voltage
WDIA0141E
SDIA2746E
Continuity should exist.
SDIA2747E

TROUBLE DIAGNOSIS FOR SYSTEMTF-107
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Revision: November 2009 2006 QX56
3. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-54, "
TRANSFER CONTROL UNIT TERMINALS
AND REFERENCE VALUE" .
OK or NG
OK >> GO TO 4.
NG >> Check transfer control unit pin terminals for damage or loose connection with the harness connec- tor. If any items are damaged, repair or replace damaged parts.
4. CHECK CLUTCH PRESSURE SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove clutch pressure switch. Refer to TF-22, "
Location of Electrical Parts" .
3. Push and release clutch pressure switch and check continuity between transfer terminal cord assembly terminal 7 and ground.
OK or NG
OK >> GO TO 5.
NG >> Replace clutch pressure switch. Refer to TF-22, "
Loca-
tion of Electrical Parts" .
5. CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> GO TO 6.
NG >> Replace transfer control unit. Refer to TF-132, "
Removal and Installation" .
6. CRUISE TEST
Perform cruise test. Refer to TF-33, "
CRUISE TEST" .
OK or NG
OK >> Inspection End.
NG >> Perform the applicable trouble diagnosis.
COMPONENT INSPECTION
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove clutch pressure switch. Refer to TF-22, "
Location of Electrical Parts" .
3. Push and release clutch pressure switch and check continuity between transfer terminal cord assembly terminal 7 and ground.
4. If NG, replace the clutch pressure switch. Refer to TF-22, "
Loca-
tion of Electrical Parts" .
TerminalCondition Continuity
7 -
Ground Push clutch pressure switch
Yes
Release clutch pressure switch No
WDIA0171E
TerminalCondition Continuity
7 - Ground Push clutch pressure switch
Yes
Release clutch pressure switch No
WDIA0171E

TROUBLE DIAGNOSIS FOR SYSTEMTF-109
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Revision: November 2009 2006 QX56
DIAGNOSTIC PROCEDURE
1. CHECK LINE PRESSURE SWITCH SIGNAL
With CONSULT-II
1. Start engine.
2. Select “DATA MONITOR ” mode for “ALL MODE AWD/4WD ” with CONSULT-II.
3. Read out ON/OFF switching action of “LINE PRES SW ” while
operating 4WD shift switch.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector terminals and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND LINE PRESSURE SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the transfer terminal cord assembly harness con- nector.
3. Check continuity between transfer control unit harness connec- tor E143 terminal 35 and transfer terminal cord assembly har-
ness connector F56 terminal 1.
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

A/T selector lever “D ” position

4WD shift switch: AUTO ON

Except the above

The vehicle has been left
at room temperature for 5
minutes and more with
ignition switch in “
OFF”
position.
Ignition switch: ON

A/T selector lever: "P" or "N"
position

4WD shift switch: other than
AUTO OFF
Connector Terminal Condition Voltage
(Approx.)
E143 35 -
Ground

A/T selector lever
“ D ” position 4WD shift switch:
AUTO
0V

Except the above

The vehicle has
been left at room
temperature for 5
minutes and more
with ignition switch
in
“OFF ” position.

Ignition switch:
ON

A/T selector
lever: "P" or "N"
position

4WD shift
switch: other
than AUTO Battery
voltage
WDIA0142E
SDIA2751E
Continuity should exist.
SDIA2752E

TF-110
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: November 20092006 QX56
3. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> GO TO 4.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.

Transfer control unit pin terminals for damage or loose connection with harness connector.

Transfer control unit. Refer to TF-132, "Removal and Installation" .
4. CHECK LINE PRESSURE SWITCH
1. Turn ignition switch “ OFF”. (Stay for at least 5 seconds.)
2. Remove line pressure switch. Refer to TF-22, "
Location of Electrical Parts" .
3. Push and release line pressure switch and check continuity between transfer terminal cord assembly terminal 1 and ground.
OK or NG
OK >> GO TO 5.
NG >> Replace line pressure switch. Refer to TF-22, "
Location
of Electrical Parts" .
5. CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> GO TO 6.
NG >> Replace transfer control unit. Refer to TF-132, "
Removal and Installation" .
6. CRUISE TEST
Perform cruise test. Refer to TF-33, "
CRUISE TEST" .
OK or NG
OK >> Inspection End.
NG >> Perform the applicable trouble diagnosis.
COMPONENT INSPECTION
1. Turn ignition switch “OFF ”. (Stay for at least 5 seconds.)
2. Remove line pressure switch. Refer to TF-22, "
Location of Electrical Parts" .
3. Push and release line pressure switch and check continuity between transfer terminal cord assembly terminal 1 and ground.
4. If NG, replace the line pressure switch. Refer to TF-22, "
Loca-
tion of Electrical Parts" .
TerminalCondition Continuity
1 -
Ground Push line pressure switch
Yes
Release line pressure switch No
WDIA0172E
TerminalCondition Continuity
1 - Ground Push line pressure switch
Yes
Release line pressure switch No
WDIA0172E

TF-114
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: November 20092006 QX56
DIAGNOSTIC PROCEDURE
1. CHECK ATP 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 “AT P S W I T C H”.
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 ATP SWITCH
1. Turn ignition switch “ OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the ATP switch harness connector.
3. Check continuity between transfer control unit harness connec- tor E143 terminal 40 and ATP switch harness connector F55 ter-
minal 8.
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"

Brake pedal
depressed 4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)
ON
Except the above OFF
SDIA2391E
Connector TerminalConditionVoltage
(Approx.)
E143 40 -
Ground

Vehicle stopped

Engine running

A/T selector lever
“ N"

Brake pedal
depressed 4WD shift switch: 4H
to 4LO or 4LO to 4H
(While actuator motor
is operating.)
0V
Except the above Battery
voltage
SDIA2755E
Continuity should exist.
SDIA2756E