Nissan Murano. Manual - part 1390

TM-102

< DTC/CIRCUIT DIAGNOSIS >

[CVT: RE0F09B]

P1777 STEP MOTOR

YES

>> GO TO 4.

NO

>> GO TO 2.

2.

CHECK HARNESS BETWEEN TCM AND CVT UNIT (STEP MOTOR) (PART 1)

1.

Disconnect CVT unit connector.

2.

Check continuity between TCM vehicle side harness connector terminals and CVT unit vehicle side har-
ness connector terminals.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace damaged parts.

3.

CHECK HARNESS BETWEEN TCM AND CVT UNIT (STEP MOTOR) (PART 2)

Check continuity between TCM vehicle side harness connector terminals and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace damaged parts.

4.

CHECK STEP MOTOR

Check step motor. Refer to 

TM-102, "Component Inspection (Step Motor)"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace transaxle assembly. Refer to 

TM-180, "Exploded View"

.

5.

DETECT MALFUNCTIONING ITEMS

Check TCM connector pin terminals for damage or loose connection with harness connector.

Is the inspection result normal?

YES

>> Replace TCM. Refer to 

TM-165, "Exploded View"

.

NO

>> Repair or replace damaged parts.

Component Inspection (Step Motor)

INFOID:0000000009719521

1.

CHECK STEP MOTOR

1.

Check resistance between CVT unit connector terminals.

TCM vehicle side harness connector

CVT unit vehicle side harness connector

Continuity

Connector

Terminal

Connector

Terminal

F23

27

F24

9

Existed

28

8

29

7

30

6

TCM vehicle side harness connector

Ground

Continuity

Connector

Terminal

F23

27

Not existed

28

29

30

CVT unit connector

Resistance (Approx.)

Connector

Terminals

F24

6

7

30.0 

Ω

8

9

P1777 STEP MOTOR

TM-103

< DTC/CIRCUIT DIAGNOSIS >

[CVT: RE0F09B]

C

E

F

G

H

I

J

K

L

M

A

B

TM

N

O

P

2.

Check resistance between CVT unit connector terminals and ground.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace transaxle assembly. Refer to 

TM-180, "Exploded View"

.

CVT unit connector

Ground

Resistance (Approx.)

Connector

terminal

F24

6

15.0 

Ω

7

8

9

TM-104

< DTC/CIRCUIT DIAGNOSIS >

[CVT: RE0F09B]

P1778 STEP MOTOR

P1778 STEP MOTOR

Description

INFOID:0000000009719522

• The step motor changes the step by turning 4 coils ON/OFF according to the signal from TCM. As a result,

the flow of line pressure to primary pulley is changed and pulley ratio is controlled.

• This diagnosis item is detected when the electrical system is OK, but the mechanical system is NG.
• This diagnosis item is detected when the state of the changing of the speed mechanism in the unit does not

operate normally.

DTC Logic

INFOID:0000000009719523

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

CAUTION:

• Always drive vehicle at a safe speed.
• Before starting “DTC CONFIRMATION PROCEDURE”, confirm “Hi” or “Mid” or “Low” fixation by

“PRI SPEED” and “VEHICLE SPEED” in “Data Monitor”.

• If hi-geared fixation occurred, go to 

TM-104, "Diagnosis Procedure"

.

NOTE:
Immediately after performing any “DTC CONFIRMATION PROCEDURE”, always turn ignition switch OFF.
Then wait at least 10 seconds before performing the next test.

1.

CHECK DTC DETECTION

With CONSULT

1.

Turn ignition switch ON.

2.

Select “Data Monitor” in “TRANSMISSION”.

3.

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

4.

Start engine and maintain the following conditions for at least 30 consecutive seconds.

With GST

Follow the procedure “With CONSULT”.

Is “P1778” detected?

YES

>> Go to 

TM-104, "Diagnosis Procedure"

.

NO

>> Check intermittent incident. Refer to 

GI-44, "Intermittent Incident"

.

Diagnosis Procedure

INFOID:0000000009719524

1.

CHECK STEP MOTOR SYSTEM

Check step motor system. Refer to 

TM-101, "DTC Logic"

.

Is the inspection result normal?

DTC

Trouble diagnosis name

DTC is detected if...

Possible cause

P1778

Step Motor Circuit Intermit-
tent

There is a big difference between the num-
ber of steps for the stepping motor and for 
the actual gear ratio.

Step motor

ATF TEMP SEN

: 1.0 – 2.0 V

If it is 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)

Start test from 0 km/h (0 MPH)

Constant acceleration

: Keep 30 seconds or more

VEHICLE SPEED

: 10 km/h (6 MPH) or more

ACC PEDAL OPEN

: More than 1.0/8

RANGE

: “D” position

ENG SPEED

: 450 rpm or more

P1778 STEP MOTOR

TM-105

< DTC/CIRCUIT DIAGNOSIS >

[CVT: RE0F09B]

C

E

F

G

H

I

J

K

L

M

A

B

TM

N

O

P

YES

>> GO TO 2.

NO

>> Repair or replace damaged parts.

2.

CHECK PRIMARY SPEED SENSOR SYSTEM

Check primary speed sensor system. Refer to 

TM-57, "DTC Logic"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace damaged parts.

3.

CHECK SECONDARY SPEED SENSOR SYSTEM

Check secondary speed sensor system. Refer to 

TM-60, "DTC Logic"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace damaged parts.

4.

DETECT MALFUNCTIONING ITEMS

Check TCM connector pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?

YES

>> Replace TCM. Refer to 

TM-165, "Exploded View"

.

NO

>> Repair or replace damaged parts.