2009 INFINITI QX56 air condition

P1810 NEUTRAL-4LO SWITCHDLN-29
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
Are inspection results normal?
YES >> GO TO 5.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TR ANSFER CONTROL UNIT AND NEUTRAL-4LO SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connecto r and the neutral-4LO switch harness connector.
3. Check continuity between transfer control unit harness connec- tor E143 terminal 25 and neutral-4LO switch harness connector
F60 terminal 13.
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 neutral-4LO switch harness connector.
3. Check continuity between neutral-4LO switch harness connec- tor F60 terminal 12 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 4LO SWITCH
1. Turn ignition switch OFF.
2. Disconnect neutral-4LO switch harness connector.
3. Remove neutral-4LO switch.
Connector Te r m i n a l
(Wire col-
or) Condition
Voltage
(Approx.)
E143 25 -
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.
SDIA2694E
Continuity should exist.
SDIA2695E
Revision: December 20092009 QX56

DLN-30
< COMPONENT DIAGNOSIS >[ATX14B]
P1810 NEUTRAL-4LO SWITCH
4. Push and release neutral-4LO switch and check continuity
between neutral-4LO switch terminals 12 and 13.
Are inspection results normal?
YES >> GO TO 5.
NO >> Replace neutral-4LO switch. Refer to DLN-16, "Compo-
nent Parts Location".
5.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "Reference Value"
.
Are inspection results normal?
YES >> GO TO 6.
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.
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-130, "Removal and Installation"
.
Component InspectionINFOID:0000000003772096
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 DLN-16, "Component Parts Location"
.
4. Push and release neutral-4LO switch and check continuity between neutral-4LO switch terminals 12 and 13.
5. If the inspection results are abnormal replace the neutral-4LO switch.
Terminal Condition Continuity
12 - 13 Push neutral-4LO switch Yes
Release neutral-4LO switch No
SDIA2696E
Terminal Condition Continuity
12 - 13 Push neutral-4LO switch Yes
Release neutral-4LO switch No
SDIA2696E
Revision: December 20092009 QX56

P1813 4WD SHIFT SWITCHDLN-33
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
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-81, "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-130, "Removal and Installation"
.
Component InspectionINFOID:0000000003772100
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 Condition Continuity
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 Condition Continuity
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: December 20092009 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 Terminal Condition Voltage
(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: December 20092009 QX56

P1814 WAIT DETECTION SWITCHDLN-37
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
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-81, "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-130, "Removal and Installation"
.
Component InspectionINFOID:0000000003772104
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
Terminal Condition Continuity
10 - 11 Push wait detection switch Yes
Release wait detection switch No
SDIA2704E
Revision: December 20092009 QX56

P1817 ACTUATOR MOTORDLN-41
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
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.
Are the inspection results normal?
YES >> GO TO 3.
NO >> Check the following. If any items are damaged, repair or replace damaged parts.  20A fuse (No. 57, located in the fuse and relay box).
 Harness for short or open between battery, transfer shift high relay harness connector terminal 5and transfer shift low relay harness connector terminal 5.
3.CHECK ACTUATOR MOTOR GROUND 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 DLN-16, "Component Parts Loca-
tion".
3. Check continuity between transfer shift high relay harness con- nector E46 terminals 2, 4 (A) and transfer shift low relay harness
connector E47 terminals 2, 4 (B) and ground.
Also check harness for short to ground and short to power.
Are the 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 TRANSFER SHIFT RELAY
1. Turn ignition switch OFF.
2. Remove transfer shift high relay and transfer shift low relay. Refer to DLN-16, "Component Parts Loca-
tion".
3. Apply 12V direct current between transfer shift relay terminals 1
and 2.
4. Check continuity between relay terminals 3 and 4, 3 and 5.
Are the inspection results normal?
YES >> GO TO 5.
NO >> Replace the transfer shut off relay. Refer to DLN-16, "Component Parts Location"
.
5.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 the transfer control device (actuator motor) har-
ness connector.
3. Remove transfer shift high relay and transfer shift low relay.
4. Check continuity between the following terminals.
Connector Terminal Voltage (Approx.)
A: E46 5 - Ground Battery voltage
B: E47 5 - Ground
WDIA0311E
Continuity should exist.
WDIA0312E
Terminal Condition Continuity
3 - 4 12V direct current supply between terminals 1 and 2 No
OFF Yes
3 - 5 12V direct current supply between terminals 1 and 2 Yes
OFF No
WIIA0291E
Revision: December 20092009 QX56

P1817 ACTUATOR MOTORDLN-43
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
3. Check resistance between transfer control device (actuator motor) terminals 21 and 24.
Are the inspection results normal?
YES >> GO TO 7.
NO >> Replace transfer control device (actuator motor).
7.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 8.
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.
8.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:0000000003772111
TRANSFER SHIFT RELAY
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Remove transfer shift high relay and transfer shift low relay. Refer to DLN-16, "Component Parts Loca-
tion".
3. Apply 12V direct current between transfer shift relay terminals 1 and 2.
4. Check continuity between relay terminals 3 and 4, 3 and 5.
5. If NG, replace transfer shift relay.
TRANSFER CONTROL DEVICE
1. Remove transfer control device. Refer to DLN-136, "Removal and Installation".
2. Check operation by applying battery voltage to transfer control device (actuator motor) terminals 21 and 24.
CAUTION:
 Do not operate actuator moto r for more than 1 second.
 Change the actuator motor posi tion to HIGH when install-
ing.
 Be careful not to overheat the harness. 21 - 24 : Approx. 0.2
Ω
SDIA2726E
Terminal Condition Continuity
3 - 4 12V direct current supply between terminals 1 and 2 No
OFF Yes
3 - 5 12V direct current supply between terminals 1 and 2 Yes
OFF No
WIIA0291E
Terminal Actuator motor
21 (Battery voltage) - 24 (Ground) Clockwise rotate
24 (Battery voltage) - 21 (G round) Counterclockwise rotate
WDIA0224E
Revision: December 20092009 QX56

DLN-46
< COMPONENT DIAGNOSIS >[ATX14B]
P1818 ACTUATOR POSITION SWITCH
2. Check voltage between transfer control unit harness connector
terminal and ground.
Are the inspection results normal?
YES >> GO TO 5.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSFER CONTRO L 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.
Are the 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 transfer control device (act uator position switch) harness connector.
3. Check continuity between transfe r control device (actuator posi-
tion switch) harness connector F58 terminal 22 and ground.
Also check harness for short to ground and short to power.
Are the 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 ACTUATOR POSITION SWITCH
1. Remove transfer control device. Refer to DLN-136, "Removal and Installation"
.
Connector Terminal Condition Voltage
(Approx.)
E143 27 -
Ground  Vehicle stopped
 Engine running
 A/T selector le-
ver N position
 Brake pedal de- pressed 4WD shift switch: 4H,
AUTO or 2WD
0V
4WD shift switch: 4LO Battery
voltage
44 -
Ground  Vehicle stopped
 Engine running
 A/T selector le-
ver N position
 Brake pedal de- pressed 4WD shift switch: 4LO 0V
4WD shift switch:
2WD, AUTO or 4H
Battery
voltage
SDIA2715E
Continuity should exist.
SDIA2716E
Continuity should exist.
SDIA2717E
Revision: December 20092009 QX56