Nissan Qashqai (2007-2010). Manual — part 580

P0840 TRANSMISSION FLUID PRESSURE SENSOR A (SEC PRESSURE SEN-

SOR)

TM-255

< COMPONENT DIAGNOSIS >

[CVT: RE0F10A]

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P0840 TRANSMISSION FLUID PRESSURE SENSOR A (SEC PRESSURE
SENSOR)

Description

INFOID:0000000000988698

The transmission fluid pressure sensor A (secondary pressure sensor) detects secondary pressure of CVT
and sends TCM the signal.

DTC Logic

INFOID:0000000000988699

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

NOTE:
If “DTC CONFIRMATION PROCEDURE” has been previously performed, always turn ignition switch
OFF and wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.

1.

CHECK DTC DETECTION

With CONSULT-III

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR”.

3.

Make sure that output voltage of line temperature sensor is within the range below.

4.

Start engine and wait for at least 5 consecutive seconds.

With GST

Follow the procedure “With CONSULT-III”.
Is “P0840 TR PRS SENS/A CIRC” detected?

YES

>> Go to

TM-255, "Diagnosis Procedure"

.

NO

>> Check intermittent incident. Refer to

GI-39, "Intermittent Incident"

.

Diagnosis Procedure

INFOID:0000000000988700

1.

CHECK INPUT SIGNAL

1.

Start engine.

2.

Check voltage between TCM connector terminal and ground.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 2.

2.

CHECK HARNESS BETWEEN TCM AND TRANSMISSION FLUID PRESSURE SENSOR A (SECOND-

DTC

Item

(CONSULT-III screen term)

Malfunction is detected when...

Possible cause

P0840

TR PRS SENS/A CIRC

Signal voltage of the transmis-
sion fluid pressure sensor A
(secondary pressure sensor) is
too high or too low while driving.

• Transmission fluid pressure

sensor A (Secondary pres-
sure sensor)

• Harness or connectors

(Switch circuit is open or
shorted.)

ATF TEMP SEN

: 1.0 – 2.0 V

If out of range, drive the vehicle to decrease the voltage (warm up the
fluid) or stop engine to increase the voltage (cool down the fluid)

TCM connector

Ground

Condition

Voltage (Approx.)

Connector

Terminal

F25

15

“N” position idle

1.0 V

TM-256

< COMPONENT DIAGNOSIS >

[CVT: RE0F10A]

P0840 TRANSMISSION FLUID PRESSURE SENSOR A (SEC PRESSURE SEN-

SOR)

ARY PRESSURE SENSOR)

1.

Turn ignition switch OFF.

2.

Disconnect TCM connector and CVT unit harness connector.

3.

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

4.

If OK, check harness for short to ground and short to power.

5.

Reinstall any part removed.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair open circuit or short to ground or short to power in harness or connectors.

3.

CHECK SENSOR POWER AND SENSOR GROUND

1.

Connect TCM connector.

2.

Turn ignition switch ON.

3.

Check voltage between CVT unit harness connector terminals.

4.

Reinstall any part removed.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

CHECK HARNESS BETWEEN TCM AND CVT UNIT HARNESS CONNECTOR (SENSOR POWER AND

SENSOR GROUND)

1.

Turn ignition switch OFF.

2.

Disconnect TCM connector.

3.

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

4.

If OK, check harness for short to ground and short to power.

5.

Reinstall any part removed.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair open circuit or short to ground or short to power in harness or connectors.

5.

CHECK THE TCM SHORT

Replace same type TCM, perform self-diagnosis check. Erase self-diagnostic results and then start engine
perform self-diagnosis check. Refer to

TM-255, "DTC Logic"

.

Is “P0840 TR PRS SENS/A CIRC” detected again?

YES

>> Replace the transaxle assembly. Refer to

TM-340, "Exploded View"

.

NO

>> Replace the TCM. Refer to

TM-325, "Exploded View"

.

6.

CHECK TCM

Check TCM input/output signals. Refer to

TM-285, "Reference Value"

.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to

GI-39, "Intermittent Incident"

.

TCM connector

CVT unit harness connector

Continuity

Connector

Terminal

Connector

Terminal

F25

15

F24

23

Existed

CVT unit harness connector

Voltage (Approx.)

Connector

Terminal

F24

19

20

5.0 V

TCM connector

CVT unit harness connector

Continuity

Connector

Terminal

Connector

Terminal

F25

25

F24

19

Existed

26

20

P0840 TRANSMISSION FLUID PRESSURE SENSOR A (SEC PRESSURE SEN-

SOR)

TM-257

< COMPONENT DIAGNOSIS >

[CVT: RE0F10A]

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B

TM

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NO

>> Replace TCM. Refer to

TM-325, "Exploded View"

.

TM-258

< COMPONENT DIAGNOSIS >

[CVT: RE0F10A]

P0841 PRESSURE SENSOR FUNCTION

P0841 PRESSURE SENSOR FUNCTION

Description

INFOID:0000000000988701

Using the engine load (throttle position), the primary pulley revolution speed, and the secondary pulley revolu-
tion speed as input signal, TCM changes the operating pressure of the primary pulley and the secondary pul-
ley and changes the groove width of the pulley to control the gear ratio.

DTC Logic

INFOID:0000000000988702

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

CAUTION:

Always drive vehicle at a safe speed.
NOTE:
If “DTC CONFIRMATION PROCEDURE” has been previously performed, always turn ignition switch
OFF and wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.

1.

CHECK DTC DETECTION

With CONSULT-III

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR”.

3.

Start engine and maintain the following conditions for at least 12 consecutive seconds.

Is “P0841 PRESS SEN/FNCTN” detected?

YES

>> Go to

TM-258, "Diagnosis Procedure"

.

NO

>> Check intermittent incident. Refer to

GI-39, "Intermittent Incident"

.

Diagnosis Procedure

INFOID:0000000000988703

1.

CHECK LINE PRESSURE

Perform line pressure test. Refer to

TM-318, "Inspection and Judgment"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace damaged parts. Refer to

TM-318, "Inspection and Judgment"

.

2.

CHECK TRANSMISSION FLUID PRESSURE SENSOR A (SECONDARY PRESSURE SENSOR) SYS-

TEM

Check transmission fluid pressure sensor A (secondary pressure sensor) system. Refer to

TM-255, "Descrip-

tion"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace damaged parts.

DTC

Item

(CONSULT-III screen term)

Malfunction is detected when...

Possible cause

P0841

PRESS SEN/FNCTN

Correlation between the values
of the transmission fluid pres-
sure sensor A (secondary pres-
sure sensor) and the
transmission fluid pressure
sensor B (primary pressure
sensor) is out of specification.

• Transmission fluid pressure

sensor A (Secondary pres-
sure sensor)

• Transmission fluid pressure

sensor B (Primary pressure
sensor)

• Harness or connectors

(Sensor circuit is open or
shorted.)

VEHICLE SPEED

: 40 km/h (25 MPH) More than

RANGE

: “D” position