Infiniti QX56 (JA60). Manual — part 294

TRANSFER CONTROL UNIT

DLN-99

< ECU DIAGNOSIS >

[ATX14B]

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CAUTION:

• If CAN COMM CIRCUIT [U1000] or CONTROL UNIT (CAN) [U1010] is displayed with other DTCs, first perform the trouble

diagnosis for CAN communication line.

• If ABS OP SIG [P1830], VDC OP SIG [P1831] or TCS OP SIG [P1832] is displayed, first perform the trouble diagnosis for ABS

system.

• If VHCL SPEED SEN·AT [P1807] is displayed, first perform the trouble diagnosis for A/T system.
NOTE:
• If SHIFT ACT POSI SW [P1818] or SHIFT ACT CIR [P1819] is displayed, first erase self-diagnostic results. (SHIFT ACT POSI SW

[P1818] or SHIFT ACT CIR [P1819] may be displayed after installing transfer control unit or transfer assembly.)

• If CL PRES SW [P1827] or LINE PRES SW [P1828] is displayed only while driving in reverse, check the continuity of R position on

transmission range switch. When there is no malfunction found in the electrical system, check the hydraulic system.

FLASH CODE CHART

[P1826]

OIL TEMP SEN

Signal voltage from transfer fluid temperature sen-
sor is abnormally high (Transfer fluid temperature is
abnormally low) while driving.

Refer to

DLN-68

.

[P1827]

CLUTCH PRES SW

• Improper signal from clutch pressure switch is in-

put due to open or short circuit.

• Malfunction occurs in clutch pressure switch or

hydraulic circuit.

Refer to

DLN-71

.

[P1828]

LINE PRES SW

• Improper signal from line pressure switch is input

due to open or short circuit.

• Malfunction occurs in line pressure switch or hy-

draulic circuit.

Refer to

DLN-74

.

[P1829]

THROTTLE POSI SEN

• Malfunction is detected in accelerator pedal posi-

tion signal that is output from ECM through CAN
communication.

• Signal voltage from accelerator pedal position

sensor is abnormally high or low.

Refer to

DLN-77

.

[P1830]

ABS OP SIG

Malfunction is detected in ABS operation signal that
is output from ABS actuator and electric unit (control
unit) through CAN communication.

Refer to

DLN-78

.

[P1831]

VDC OP SIG

Malfunction is detected in VDC operation signal that
is output from ABS actuator and electric unit (control
unit) through CAN communication.

Refer to

DLN-79

.

[P1832]

TCS OP SIG

Malfunction is detected in TCS operation signal that
is output from ABS actuator and electric unit (control
unit) through CAN communication.

Refer to

DLN-80

.

DTC

CONSULT-III

Diagnostic item is detected when...

Reference

Flashing pattern

Item

Diagnostic item is detected when...

Reference

2

Vehicle speed signal
(from A/T)

• Malfunction is detected in output shaft revolution signal

that is output from TCM through CAN communication.

• Improper signal is input while driving.

Refer to

DLN-27

.

3

Clutch pressure sole-
noid signal

Proper voltage is not applied to clutch pressure solenoid
valve due to open or short circuit.

Refer to

DLN-54

.

4

2-4WD solenoid signal

Proper voltage is not applied to 2-4WD solenoid valve due
to open or short circuit.

Refer to

DLN-58

.

5

Transfer motor

Transfer motor does not operate properly due to open or
short circuit in transfer motor or transfer motor relay.

Refer to

DLN-62

.

6

Vehicle speed signal
(from ABS)

• Malfunction is detected in vehicle speed signal that is out-

put from ABS actuator and electric unit (control unit)
through CAN communication.

• Improper signal is input while driving.

Refer to

DLN-28

.

7

CAN communication

Malfunction has been detected from CAN communication
line.

Refer to

LAN-14

.

8

AD converter

AD converter system of transfer control unit is malfunction-
ing.

Refer to

DLN-25

.

DLN-100

< ECU DIAGNOSIS >

[ATX14B]

TRANSFER CONTROL UNIT

9

Transfer fluid tempera-
ture

Signal voltage from transfer fluid temperature sensor is ab-
normally high (Transfer fluid temperature is abnormally low)
while driving.

Refer to

DLN-68

.

10

Neutral-4LO switch

Improper signal from neutral-4LO switch is input due to
open or short circuit.

Refer to

DLN-29

.

11

Clutch pressure switch

• Improper signal is input due to open or short circuit.
• Malfunction occurs in clutch pressure switch or hydraulic

circuit.

Refer to

DLN-71

.

12

Line pressure switch

• Improper signal is input due to open or short circuit.
• Malfunction occurs in line pressure switch or hydraulic

circuit.

Refer to

DLN-74

.

13

Engine speed signal
(from ECM)

• Malfunction is detected in engine speed signal that is out-

put from ECM through CAN communication.

• Improper signal is input while driving.

Refer to

DLN-53

.

14

Accelerator pedal posi-
tion sensor (from
ECM)

• Malfunction is detected in accelerator pedal position sig-

nal that is output from ECM through CAN communication.

• Signal voltage from accelerator pedal position sensor is

abnormally high or low.

Refer to

DLN-77

.

15

Power supply

Power supply voltage for transfer control unit is abnormally
low while driving.

Refer to

DLN-22

.

16

4WD shift switch

More than two switch inputs are simultaneously detected
due to short circuit of 4WD shift switch.

Refer to

DLN-32

.

17

ABS operation signal
(from ABS)

Malfunction is detected in ABS operation signal that is out-
put from ABS actuator and electric unit (control unit)
through CAN communication.

Refer to

DLN-78

.

18

Wait detection switch

Improper signal from wait detection switch is input due to
open or short circuit.

Refer to

DLN-36

.

19

Actuator motor

• Motor does not operate properly due to open or short cir-

cuit in actuator motor.

• Malfunction is detected in the actuator motor. (When

4WD shift switch is operated and actuator motor is not
operated)

• Malfunction is detected in transfer shift high relay and

transfer shift low relay.

Refer to

DLN-40

.

20

Actuator position
switch

• Improper signal from actuator position switch is input due

to open or short circuit.

• Malfunction is detected in the actuator position switch.

Refer to

DLN-46

.

21

Actuator circuit

• Transfer control device actuator circuit is shorted or open.

(Malfunctions are detected when motor relay circuit is
open/shorted or relay transfer shift circuit is open/short-
ed.)

• Malfunction occurs in transfer control device drive circuit.

Refer to

DLN-49

.

22

VDC operation signal
(from VDC)

Malfunction is detected in VDC operation signal that is out-
put from ABS actuator and electric unit (control unit)
through CAN communication.

Refer to

DLN-79

.

23

TCS operation signal
(from TCS)

Malfunction is detected in TCS operation signal that is out-
put from ABS actuator and electric unit (control unit)
through CAN communication.

Refer to

DLN-80

.

24

Transmission range
switch signal (from
TCM)

When transmission range switch signal is malfunction or
communication error between the vehicles.

Refer to

DLN-39

.

Repeats flickering
every 2 to 5 sec.

—

System normal.

Refer to

DLN-102

Flashing pattern

Item

Diagnostic item is detected when...

Reference

TRANSFER CONTROL UNIT

DLN-101

< ECU DIAGNOSIS >

[ATX14B]

C

E

F

G

H

I

J

K

L

M

A

B

DLN

N

O

P

CAUTION:

• If CAN communication is displayed with 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 or 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 position 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-39

or

DLN-32

.

Flashing pattern

Item

Diagnostic item is detected when...

Reference

DLN-102

< SYMPTOM DIAGNOSIS >

[ATX14B]

4WD SYSTEM SYMPTOMS

SYMPTOM DIAGNOSIS

4WD SYSTEM SYMPTOMS

Symptom Table

INFOID:0000000005148856

If 4WD warning lamp turns ON, perform self-diagnosis. Refer to

DLN-18, "CONSULT-III Function (ALL MODE AWD/4WD)"

.

NOTE:

• Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not a

malfunction.

• Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: 4WD shift

switch is 4H or 4LO, steering wheel is turned fully to either side.

Symptom

Condition

Reference page

4WD shift indicator lamp and 4LO indicator lamp do not turn ON
(4WD shift indicator lamp and 4LO indicator lamp check)

Ignition switch: ON

DLN-103

4WD warning lamp does not turn ON
(4WD warning lamp check)

Ignition switch: ON

DLN-105

4WD shift indicator lamp or 4LO indicator lamp does not change

Engine running

DLN-107

ATP warning lamp does not turn ON

Engine running

DLN-109

4WD shift indicator lamp keeps flashing

Engine running

DLN-111

4WD warning lamp flashes rapidly (2 times/second)

While driving

DLN-112

4WD warning lamp flashes slowly
(1 time/2 seconds)

While driving

DLN-113

Heavy tight-corner braking symptom occurs
(See NOTE.)

• While driving
• AUTO mode
• Steering wheel is turned fully

to either side

DLN-114

ATP switch does not operate

Engine running

DLN-116

4WD system does not operate

While driving

DLN-118