Infiniti QX56 (JA60). Manual - part 288

P1828 LINE PRESSURE SWITCH

DLN-75

< COMPONENT DIAGNOSIS >

[ATX14B]

C

E

F

G

H

I

J

K

L

M

A

B

DLN

N

O

P

2. Check voltage between transfer control unit harness connector

terminals and ground.

Are inspection results normal?

YES

>> GO TO 5.

NO

>> 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.

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.

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

SDIA2751E

Continuity should exist.

SDIA2752E

Terminal

Condition

Continuity

1 - 

Ground

Push line pressure switch

Yes

Release line pressure switch

No

WDIA0172E

DLN-76

< COMPONENT DIAGNOSIS >

[ATX14B]

P1828 LINE PRESSURE SWITCH

5.

CHECK DTC

Perform the self-diagnosis, after driving a vehicle for a while.
Are inspection results normal?

YES

>> GO TO 6.

NO

>> Replace transfer control unit. Refer to 

DLN-130, "Removal and Installation"

.

6.

CRUISE TEST

Perform cruise test. Refer to 

DLN-7, "Preliminary Check"

.

Are inspection results normal?

YES

>> Inspection End.

NO

>> Perform the applicable trouble diagnosis.

Component Inspection

INFOID:0000000005148840

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.

4. If the inspection results are abnormal, replace the line pressure

switch.

Terminal

Condition

Continuity

1 - Ground

Push line pressure switch

Yes

Release line pressure switch

No

WDIA0172E

P1829 THROTTLE POSITION SIGNAL (ECM)

DLN-77

< COMPONENT DIAGNOSIS >

[ATX14B]

C

E

F

G

H

I

J

K

L

M

A

B

DLN

N

O

P

P1829 THROTTLE POSITION SIGNAL (ECM)

Description

INFOID:0000000005148841

Malfunction is detected in accelerator pedal position signal that is output from ECM through CAN communica-

tion.  Also, the signal voltage from accelerator pedal position sensor may be abnormally high or low.

DTC Logic

INFOID:0000000005148842

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC CONFIRMATION PROCEDURE

1. Turn ignition switch ON.

2. Perform self-diagnosis.
Is DTC P1829 displayed?

YES

>> Perform diagnosis procedure. Refer to 

DLN-77, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000005148843

1.

CHECK DTC WITH ECM

Perform self-diagnosis with ECM. Refer to 

EC-63, "CONSULT-III Function (ENGINE)"

.

Is any malfunction detected by self-diagnosis?

YES

>> Check the malfunctioning system.

NO

>> GO TO 2.

2.

CHECK TRANSFER CONTROL UNIT

Check transfer control unit input/output signal. Refer to 

DLN-81, "Reference Value"

.

Are inspection results normal?

YES

>> GO TO 3.

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.

3.

CHECK DTC

Perform the self-diagnosis, after driving a vehicle for a while.
Are inspection results normal?

YES

>> Inspection End.

NO

>> Perform self-diagnosis with ECM again.

DTC

CONSULT-III

Diagnostic item is detected when...

Reference

[P1829]

THROTTLE POSI SEN

• Malfunction is detected in accelerator 

pedal position signal that is output 
from ECM through CAN communica-
tion.

• Signal voltage from accelerator pedal 

position sensor is abnormally high or 
low.

Refer to 

DLN-77

.

DLN-78

< COMPONENT DIAGNOSIS >

[ATX14B]

P1830 ABS OPERATION SIGNAL (ABS)

P1830 ABS OPERATION SIGNAL (ABS)

Description

INFOID:0000000005148844

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

through CAN communication.

DTC Logic

INFOID:0000000005148845

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC CONFIRMATION PROCEDURE

1. Turn ignition switch ON.

2. Perform self-diagnosis.
Is DTC P1830 displayed?

YES

>> Perform diagnosis procedure. Refer to 

DLN-78, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000005148846

1.

CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)

Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to 

BRC-23, "CONSULT-III

Function (ABS)"

.

Is any malfunction detected by self-diagnosis?

YES

>> Check the malfunctioning system.

NO

>> GO TO 2.

2.

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 3.

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.

3.

CHECK DTC

Perform the self-diagnosis, after driving a vehicle for a while.
Are the inspection results normal?

YES

>> Inspection End.

NO

>> Perform self-diagnosis with ABS actuator and electric unit (control unit) again.

DTC

CONSULT-III

Diagnostic item is detected when...

Reference

[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

.