2009 INFINITI QX56 battery

DLN-74
< COMPONENT DIAGNOSIS >[ATX14B]
P1828 LINE PRESSURE SWITCH
Are inspection results normal?
YES >> GO TO 5.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSFER CONT
ROL 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.
Are inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "Reference Value"
.
Are inspection results normal?
YES >> GO TO 4.
NO >> 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 DLN-130, "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 DLN-16, "Component Parts Location"
.
3. Push and release line pressure switch and check continuity between terminal 1 and ground.
Are inspection results normal?
YES >> GO TO 5.
NO >> Replace line pressure switch.
5.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
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 le-
ver: P or N posi-
tion
 4WD shift
switch: other
than AUTO Battery
voltage
Continuity should exist.
SDIA2752E
Terminal Condition Continuity
1 -
Ground Push line pressure switch Yes
Release line pressure switch No
WDIA0172E
Revision: December 20092009 QX56

TRANSFER CONTROL UNITDLN-81
< ECU DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
ECU DIAGNOSIS
TRANSFER CONTROL UNIT
Reference ValueINFOID:0000000003772158
VALUE ON THE DIAGNOSIS TOOL
CONSULT-III data monitor item
Monitored item [Unit] Content Condition Display value
VHCL/S SEN·FR [km/h]
or [mph] Wheel speed (Front
wheel) Vehicle stopped 0 km/h (0 mph)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.
Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±
10%)
VHCL/S SEN·RR [km/h]
or [mph] Wheel speed (Rear
wheel) Vehicle stopped 0 km/h (0 mph)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.
Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±
10%)
ENGINE SPEED [rpm ] Engine speed Engine stopped
(Engine speed: Less than 400 rpm)
0 rpm
Engine running
(Engine speed: 400 rpm or more) Approximately
equal to the indica-
tion on tachometer
THRTL POS SEN [V] Accelertor pedal position
(APP) sensor signal volt-
age Accelerator pedal: Released Approx. 0.5V
Accelerator pedal: Fully depressed Approx. 4.0V
FLUID TEMP SE [V] Transfer fluid tempera-
ture signal voltage Transfer fluid temperature approx. 20 - 80
°C (68 - 176 °F) Approx. 1.1 - 0.3V
BATTERY VOLT [V] Power supply voltage for
transfer control unit Ignition switch: ON Battery voltage
2WD SWITCH [ON/OFF] Input condition from 4WD
shift switch 4WD shift switch: 2WD ON
4WD shift switch: AUTO, 4H or 4LO OFF
AUTO SWITCH [ON/
OFF] Input condition from 4WD
shift switch 4WD shift switch: AUTO ON
4WD shift switch: 2WD, 4H or 4LO OFF
LOCK SWITCH [ON/
OFF] Input condition from 4WD
shift switch 4WD shift switch: 4H ON
4WD shift switch: 2WD, AUTO or 4LO OFF
4L SWITCH [ON/OFF] Input condition from 4WD
shift switch 4WD shift switch: 4LO ON
4WD shift switch: 2WD, AUTO or 4H OFF
N POSI SW TF [ON/
OFF] Condition of neutral-4LO
switch  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 2WD,
AUTO or 4H
OFF
4WD shift switch: 4H to
4LO (While actuator mo-
tor is operating.) OFF
→ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.) ON
→OFF
4WD shift switch: 4LO ON
Revision: December 20092009 QX56

TRANSFER CONTROL UNITDLN-85
< ECU DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
PHYSICAL VALUES
Terminal Layout
SHIFT AC MON2 [ON/
OFF] Check signal for transfer
control unit signal output  Vehicle stopped
 Engine running
 A/T selector lever N posi-
tion
 Brake pedal depressed 4WD shift switch: 4LO to
4H (Wait function is oper-
ating.)
ON
Except the above OFF
T/F F SPEED [km/h] or
[mph] Displayed, but do not use.
A/T R SPEED [km/h] or
[mph] Condition of vehicle
speed sensor A/T (output
speed sensor)
During driving Approximately
matches the out-
put shaft speed.
AT GEAR POSI [1/2/3/4/
5] Condition of A/T selector
lever position
Displays actual A/T gear position. 1
2
3
4
5
Monitored item [Unit] Content Condition Display value
WDIA0378E
Te r m i n a l
Wire
color Item Condition Data (Approx.)
1 GR 2-4WD shift solenoid valve  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: 2WD 0V
4WD shift switch: AUTO, 4H or 4LO Battery voltage
2 B/W 4WD shift indicator lamp
(2WD indicator lamp) 2WD indicator lamp: OFF Battery voltage
2WD indicator lamp: ON 0V
3 B Ground Always 0V
4 Y/L Transfer shift high relay  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de-
pressed 4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
5 W/B 4WD warning lamp 4WD warning lamp: ON 0V
4WD warning lamp: OFF Battery voltage
6 B Ground Always 0V
7 L CAN-H — —
8 P CAN-L — —
9G/W 4WD shift switch
(2WD) Ignition switch: ON4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V
Revision: December 20092009 QX56

DLN-86
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
10 L/W Transfer dropping resistor Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: AUTO 4 - 14V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
11 L 4WD shift indicator lamp
(Lock indicator lamp) Lock indicator lamp of 4WD shift indicator lamp: OFF Battery voltage
Lock indicator lamp of 4WD shift indicator lamp: ON 0V
12 W/G 4LO indicator lamp 4LO indicator lamp: OFF Battery voltage
4LO indicator lamp: ON 0V
13 G/B Transfer shift low relay  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de-
pressed 4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
14 LG Transfer motor relay  Accelerator pedal
depressed
 Vehicle stopped
 Engine running
 Brake pedal de- pressed 4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO or 4LO (A/T selec-
tor lever “P” or “N” position)
Battery voltage
(0V for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except for
A/T selector lever “P” or “N” position) 0V
4WD shift switch: 4H (A/T selector lever
“P” position) Battery voltage
(0V for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T selec-
tor lever “P” position) 0V
15 L/B ATP warning lamp ATP indicator lamp: ON 0V
ATP indicator lamp: OFF Battery voltage
16 Y/R Power supply Ignition switch: ON Battery voltage
Ignition switch: OFF 0V
18 O 4WD shift switch
(4H) Ignition switch: ON4WD shift switch: 4H Battery voltage
4WD shift switch: 2WD, AUTO or 4LO 0V
19 L Clutch pressure solenoid
valve  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: AUTO 1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
21 BR 4WD shift indicator lamp
(AUTO indicator lamp)  AUTO indicator lamp of 4WD shift indicator lamp: OFF Battery voltage
AUTO indicator lamp of 4WD shift indicator lamp: ON 0V
22 Y/R Power supply Ignition switch: ON Battery voltage
Ignition switch: OFF 0V
23 R 4WD shift switch
(4LO)
Ignition switch: ON4WD shift switch: 4LO Battery voltage
4WD shift switch: 2WD, AUTO or 4H 0V
24 LG/R 4WD shift switch
(AUTO)
Ignition switch: ON4WD shift switch: AUTO Battery voltage
4WD shift switch: 2WD, 4H or 4LO 0V
Te r m i n a l
Wire
color Item Condition Data (Approx.)
Revision: December 20092009 QX56

TRANSFER CONTROL UNITDLN-87
< ECU DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
25 V Neutral-4LO switch  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 actua-
tor motor is operating.)
Battery voltage
→
0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.) 0V
→ Battery
voltage
4WD shift switch: 4LO 0V
27 W/L Actuator position switch 2
(High)  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de-
pressed 4WD shift switch: 4H, AUTO or 2WD 0V
4WD shift switch: 4LO Battery voltage
28 B/G Sensor ground Always 0V
29 L/W Ignition switch monitor Ignition switch: ON Battery voltage
Ignition switch: OFF 0V
30 SB Shut off relay Ignition switch: ON 0V
Ignition switch: OFF Battery voltage
31 G Transfer fluid temperature
sensor
Ignition switch: ONTransfer fluid temperature approx. 20
°C
(68 °F) 1.1V
Transfer fluid temperature approx. 80 °C
(176 °F) 0.3V
33 R/L Transfer shift high relay
monitor  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
34 BR Clutch pressure switch  Vehicle stopped
 Engine running
 A/T selector lever
“D” position 4WD shift switch: AUTO or 4H (“Wait” func-
tion is not operating.)
0V
 Vehicle stopped
 Engine running 4WD shift switch: 2WD (“Wait” function is
not operating.)
Battery voltage
35 BR/
W Line pressure switch  Ignition switch: ON
 A/T selector lever “D” position
 4WD shift switch: AUTO
0V
 After the vehicle has been left at
room temperature
for 5 minutes and
more with ignition
switch in “OFF” po-
sition.  Ignition switch: ON
 A/T selector lever: “P” or "N" position
 4WD shift switch: other than AUTO
Battery voltage
40 L/Y ATP switch  Vehicle stopped
 Engine running
 A/T selector lever
“N”
 Brake pedal de- pressed 4WD shift switch: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)
0V
Except the above Battery voltage
Te r m i n a l
Wire
color Item Condition Data (Approx.)
Revision: December 20092009 QX56

DLN-88
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
NOTE:
Data are reference value and are measured between each terminal and ground.
41 RTransfer motor relay moni-
tor  Accelerator pedal
depressed
 Vehicle stopped
 Engine running
 Brake pedal de- pressed 4WD shift switch: 2WD 0V
4WD shift switch: AUTO or 4LO (A/T selec-
tor lever “P” or “N” position)
0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except for
A/T selector lever “P” or “N” position) Battery voltage
4WD shift switch: 4H (A/T selector lever
“P” position) 0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T selec-
tor lever “P” position) Battery voltage
42 P/G Transfer shift low relay
monitor  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de-
pressed 4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)
Battery voltage
Except the above 0V
43 G/Y Wait detection switch  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 actua-
tor motor is operating.)
Battery voltage
→
0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.) 0V
→ Battery
voltage
4WD shift switch: 4LO 0V
44 LG/B Actuator position switch 1
(Low)  Vehicle stopped
 Engine running
 A/T selector lever
“N” position
 Brake pedal de- pressed 4WD shift switch: 4LO 0V
4WD shift switch: 2WD, AUTO or 4H Battery voltage
45 B Ground Always 0V
47 W Power supply
(Memory back-up) Ignition switch: ON Battery voltage
Ignition switch: OFF Battery voltage
Te r m i n a l
Wire
color Item Condition Data (Approx.)
Revision: December 20092009 QX56

TRANSFER CONTROL UNITDLN-101
< ECU DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
CAUTION:
 If CAN communication is displayed wi th other DTCs, first perform the trouble diagnosis for CAN communication line.
 If ABS operation signal, VDC operation signal or TCS operation signal is displayed, first perform the trouble diagnosis for ABS system.
 If Output shaft revolution signal is displayed, first perform the trouble diagnosis for A/T system.
NOTE:
 If actuator position switch or actuator circuit is displayed, first erase self-diagnostic results. (Actuator position switch o r actuator circuit
may be displayed after installing transfer control unit or transfer assembly.)
 If clutch pressure switch or line pressure switch is displayed only while driving in reverse, check the continuity of R positi on on trans-
mission range switch. When there is no malfunction found in the electrical system, check the hydraulic system.
Repeats flickering
every 0.25 sec.
Data erase display  Power supply failure of memory back-up.
 Battery performance is poor. Refer to
DLN-22
.
No flickering Transmission range
switch or 4WD shift
switch Transmission range switch or 4WD shift switch circuit is
shorted or open.
Refer to
DLN-38
or
DLN-31
.
Flashing pattern Item Diagnostic item is detected when... Reference
Revision: December 20092009 QX56

DLN-116
< SYMPTOM DIAGNOSIS >[ATX14B]
ATP SWITCH
ATP SWITCH
DescriptionINFOID:0000000003772178
The ATP indicator is ON when the transfer case is not in neutral.
Diagnosis ProcedureINFOID:0000000003772179
DIAGNOSTIC PROCEDURE
1.CHECK ATP SWITCH SIGNAL

With CONSULT-III
1. Start engine.
2. Select DATA MONITOR mode for A LL MODE AWD/4WD with CONSULT-III.
3. Read out the value of ATP SWITCH.
Without CONSULT-III
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
Are inspection results normal?
YES >> GO TO 5.
NO >> 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 c onnector 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.
Are inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK GROUND CIRCUIT
Condition Display value
 Vehicle stopped
 Engine running
 A/T selector lever N
 Brake pedal de- pressed 4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)
ON
Except the above OFF
Connector Terminal Condition Voltage
(Approx.)
E143 40 -
Ground  Vehicle stopped
 Engine running
 A/T selector lever
N
 Brake pedal de- pressed 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
Revision: December 20092009 QX56