Nissan Quest E52. Manual - part 1218

TM-102

< DTC/CIRCUIT DIAGNOSIS >

[CVT: RE0F09B]

P0778 PRESSURE CONTROL SOLENOID B

P0778 PRESSURE CONTROL SOLENOID B

DTC Logic

INFOID:0000000009650164

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

CAUTION:

Always drive vehicle at a safe speed.

1.

PRECONDITIONING

If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.

>> GO TO 2.

2.

CHECK DTC DETECTION

With CONSULT

1.

Start the engine.

2.

Drive the vehicle at least for 10 seconds.

3.

Stop the vehicle.

4.

Check DTC.

With GST

Follow the procedure “With CONSULT”.

Is “P0778” detected?

YES

>> Go to 

TM-102, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009650165

1.

CHECK SECONDARY PRESSURE SOLENOID VALVE

1.

Disconnect the CVT unit connector.

2.

Check the secondary pressure solenoid valve. Refer to 

TM-103, "Component Inspection (Secondary

Pressure Solenoid Valve)"

.

Is the inspection result normal?

YES 

>> GO TO 2.

NO

>> Replace the transaxle assembly due to malfunction in the secondary pressure solenoid valve.

Refer to 

TM-174, "Removal and Installation"

.

2.

CHECK HARNESS BETWEEN TCM AND CVT UNIT

1.

Disconnect TCM connector.

2.

Check the continuity between TCM harness connector terminal and CVT unit harness connector terminal.

DTC

Trouble diagnosis name

DTC detection condition

Possible cause

P0778

Pressure Control Solenoid 
“B” Electrical

Secondary pressure solenoid valve monitor volt-
age value of TCM keeps less than 70% of com-
mand voltage for 1 second or more

• Harness or connectors

(Secondary pressure solenoid valve 
circuit is open or shorted.)

• Secondary pressure solenoid valve

When below diagnosis conditions are met, sec-
ondary pressure solenoid valve monitor current 
value of TCM keeps less than 400 mA for 5 sec-
onds or more
• Diagnosis Condition
- Secondary pressure solenoid valve command 

current value: 750 mA or more

P0778 PRESSURE CONTROL SOLENOID B

TM-103

< DTC/CIRCUIT DIAGNOSIS >

[CVT: RE0F09B]

C

E

F

G

H

I

J

K

L

M

A

B

TM

N

O

P

3.

Check the continuity between TCM harness connector terminal and ground.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-42, "Intermittent Incident"

.

NO

>> Repair or replace damaged parts.

Component Inspection (Secondary Pressure Solenoid Valve)

INFOID:0000000009650166

1.

CHECK SECONDARY PRESSURE SOLENOID VALVE

Check the resistance between CVT unit connector terminal and ground.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace the transaxle assembly due to malfunction in the secondary pressure solenoid valve.

Refer to 

TM-174, "Removal and Installation"

.

TCM

CVT unit

Continuity

Connector

Terminal

Connector

Terminal

F23

39

F24

3

Existed

TCM

—

Continuity

Connector

Terminal

F23

39

Ground

Not existed

CVT unit

—

Condition

Resistance (Approx.)

Terminal

3

Ground

CVT fluid temperature: 20

°

C (68

°

F)

5.60 – 6.60 

Ω

CVT fluid temperature: 50

°

C (122

°

F)

6.76 – 6.87 

Ω

CVT fluid temperature: 80

°

C (176

°

F)

7.47 – 7.59 

Ω

TM-104

< DTC/CIRCUIT DIAGNOSIS >

[CVT: RE0F09B]

P0840 TRANSMISSION FLUID PRESSURE SEN/SW A

P0840 TRANSMISSION FLUID PRESSURE SEN/SW A

DTC Logic

INFOID:0000000009650167

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If “DTC CONFIRMATION PROCEDURE” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.

>> GO TO 2.

2.

CHECK DTC DETECTION

With CONSULT

1.

Start the engine.

2.

Warm up the engine. [Set the CVT fluid to 

−

19

°

C (

−

4

°

F) or more.]

NOTE:
When the ambient temperature is 20

°

C (68

°

F), the CVT fluid usually increases to 50 to 80

°

C (122 to

176

°

F) with driving in an urban area for approximately 10 minutes.

3.

Wait for 10 seconds or more.

4.

Check DTC.

With GST

Follow the procedure “With CONSULT”.
Is “P0840” detected?

YES

>> Go to 

TM-104, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009650168

1.

CHECK TCM INPUT SIGNAL

1.

Start the engine.

2.

Check the voltage between TCM connector terminals.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-42, "Intermittent Incident"

.

NO

>> GO TO 2.

2.

CHECK POWER AND SENSOR GROUND

DTC

Trouble diagnosis name

DTC detection condition

Possible cause

P0840

Transmission Fluid Pressure 
Sensor/Switch “A” Circuit

When below diagnosis conditions are met, secondary 
pressure sensor value is kept 4.7 V or more for 5 seconds 
or more
• Diagnosis Conditions
- CVT fluid temperature: More than 

−

20

°

C (

−

4

°

F)

- Target secondary pressure: 5.7 MPa or less

• Harness or connectors

(Secondary pressure sensor 
circuit is open or shorted.)

• Secondary pressure sensor

When below diagnosis conditions are met, secondary 
pressure sensor value is kept 0.09 V or less for 5 seconds 
or more
• Diagnosis Condition
- CVT fluid temperature: More than 

−

20

°

C (

−

4

°

F)

TCM

Condition

Voltage (Approx.)

Connector

+

-

Terminal

F23

15

25

“N” position idle

1.0 V

P0840 TRANSMISSION FLUID PRESSURE SEN/SW A

TM-105

< DTC/CIRCUIT DIAGNOSIS >

[CVT: RE0F09B]

C

E

F

G

H

I

J

K

L

M

A

B

TM

N

O

P

1.

Turn ignition switch OFF.

2.

Check the voltage between TCM terminals.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Go to 

TM-114, "Diagnosis Procedure"

.

3.

CHECK HARNESS BETWEEN TCM AND CVT UNIT

1.

Turn ignition switch OFF.

2.

Disconnect the TCM connector.

3.

Disconnect the CVT unit connector.

4.

Check continuity between TCM harness connector terminals and CVT unit harness connector terminals.

5.

Check continuity between TCM harness connector terminals and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace damaged parts.

4.

PERFORM INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace the transaxle assembly due to malfunction in the secondary pressure sensor. Refer to

TM-174, "Removal and Installation"

.

NO

>> Repair or replace damaged parts.

TCM

Condition

Voltage (Approx.)

Connector

+

-

Terminal

F23

25

26

Turn ignition switch ON

5.0 V

Turn ignition switch OFF

0 V

TCM

CVT unit

Continuity

Connector

Terminal

Connector

Terminal

F23

15

F24

23

Existed

25

19

26

20

TCM

—

Continuity

Connector

Terminal

F23

15

Ground

Not existed

25

26