Nissan Murano Z50 (2003 year). Manual

CVT SYSTEM

CVT-33

CVT

Revision; 2004 April

2003 Murano

Input/Output Signal Chart

T: Transmit R: Receive

Signals

ECM

TCM

Low

tire

pres-

sure

warn-

ing

con-

trol

unit

Dis-
play

unit

Dis-
play

con-

trol

unit

BCM

Uni-

fied

meter

and A/

amp.

Driver

seat
con-

trol

unit

AWD

con-

trol

unit

ABS

actua-

tor

and

elec-

tric

unit

(con-

trol

unit)

IPDM

E/R

CVT position indicator signal

Second position signal

Second position indicator signal

Engine speed signal

Engine status signal

Engine coolant temperature signal

Accelerator pedal position signal

Closed throttle position signal

Wide open throttle position signal

Key switch signal

Ignition switch signal

P range signal

Stop lamp switch signal

Fuel consumption monitor signal

CVT self-diagnosis signal

ABS operation signal

Air conditioner switch signal

A/C compressor request signal

A/C compressor feedback signal

Blower fan motor switch signal

A/C control signal

Cooling fan speed request signal

Position lights request signal

Low beam request signal

Low beam status signal

High beam request signal

High beam status signal

Front fog lights request signal

Vehicle speed signal

Sleep request 1 signal

Sleep request 2 signal

Door switch signal

Key fob ID signal

Key fob door unlock signal

CVT-34

CVT SYSTEM

Revision; 2004 April

2003 Murano

Turn indicator signal

Seat belt buckle switch signal

Oil pressure switch signal

Buzzer output signal

Fuel level sensor signal

Fuel level low warning signal

Malfunction indicator lamp signal

ASCD SET lamp signal

ASCD CRUISE lamp signal

Input shaft revolution signal

Output shaft revolution signal

Front wiper request signal

Front wiper stop position signal

Rear window defogger switch signal

Rear window defogger control signal

Engine and CVT integrated control
signal

Hood switch signal

Theft warning horn request signal

Horn chirp signal

Tire pressure signal

Tire pressure data signal

ABS warning lamp signal

Brake warning lamp signal

System setting signal

AWD warning lamp signal

AWD lock indicator lamp signal

AWD lock switch signal

Parking brake switch signal

Signals

ECM

TCM

Low

tire

pres-

sure

warn-

ing

con-

trol

unit

Dis-
play

unit

Dis-
play

con-

trol

unit

BCM

Uni-

fied

meter

and A/

amp.

Driver

seat
con-

trol

unit

AWD

con-

trol

unit

ABS

actua-

tor

and

elec-

tric

unit

(con-

trol

unit)

IPDM

E/R

CVT-38

CVT SYSTEM

Revision; 2004 April

2003 Murano

Input/Output Signal Chart

T: Transmit R: Receive

Signals

ECM

TCM

Low

tire

pres-

sure

warn-

ing

con-

trol

unit

Dis-
play

unit

Dis-
play

con-

trol

unit

BCM

Uni-

fied

meter

and
A/C

amp.

Steer

ing

angle

sen-

sor

Drive

r seat

con-

trol

unit

AWD

con-

trol

unit

ABS

actu-

ator
and

elec-

tric

unit

(con-

trol

unit)

IPDM

E/R

Engine and CVT integrated control
signal

Second position signal

VDC operation signal

Stop lamp switch signal

Key switch signal

Ignition switch signal

P range signal

Closed throttle position signal

Wide open throttle position signal

Second position indicator signal

Engine speed signal

Engine status signal

Engine coolant temperature signal

Accelerator pedal position signal

Fuel consumption monitor signal

CVT self-diagnosis signal

Input shaft revolution signal

Output shaft revolution signal

Air conditioner switch signal

A/C compressor request signal

A/C compressor feedback signal

Blower fan motor switch signal

A/C control signal

Cooling fan speed request signal

Position lights request signal

Low beam request signal

Low beam status signal

High beam request signal

High beam status signal

Front fog lights request signal

Vehicle speed signal

Sleep request 1 signal

Sleep request 2 signal

CVT SYSTEM

CVT-39

CVT

Revision; 2004 April

2003 Murano

Door switch signal

Turn indicator signal

Key fob ID signal

Key fob door unlock signal

Seat belt buckle switch signal

Oil pressure switch signal

Buzzer output signal

Fuel level sensor signal

Fuel level low warning signal

Malfunction indicator signal

ASCD SET lamp signal

ASCD CRUISE lamp signal

Front wiper request signal

Front wiper stop position signal

Rear window defogger switch signal

Rear window defogger control signal

Hood switch signal

Theft warning horn request signal

Horn chirp signal

Steering angle sensor signal

Tire pressure signal

Tire pressure data signal

CVT position indicator signal

ABS warning lamp signal

VDC OFF indicator lamp signal

SLIP indicator lamp signal

Brake warning lamp signal

System setting signal

AWD warning lamp signal

AWD lock indicator lamp signal

AWD lock switch signal

Parking brake switch signal

Signals

ECM

TCM

Low

tire

pres-

sure

warn-

ing

con-

trol

unit

Dis-
play

unit

Dis-
play

con-

trol

unit

BCM

Uni-

fied

meter

and
A/C

amp.

Steer

ing

angle

sen-

sor

Drive

r seat

con-

trol

unit

AWD

con-

trol

unit

ABS

actu-

ator
and

elec-

tric

unit

(con-

trol

unit)

IPDM

E/R

CVT-40

CVT SYSTEM

Revision; 2004 April

2003 Murano

Input/Output Signal of TCM

ACS0020J

*1: Input by CAN communications.
*2: If these input and output signals are different, the TCM triggers the fail-safe function.

Line Pressure and Secondary Pressure Control

ACS0020K

●

When an input torque signal equivalent to the engine drive force is sent from the ECM to the TCM, the
TCM controls the line pressure solenoid valve and secondary pressure solenoid valve.

●

This line pressure solenoid controls the pressure regulator valve as the signal pressure and adjusts the
pressure of the operating oil discharged from the oil pump to the line pressure most appropriate to the
driving state. Secondary pressure is made by line pressure decreasing.

Control item

Fluid

pressure

control

Select
control

Shift con-

trol

Lock-up

control

CAN

communi-

cation

control

Fail-safe

function

(*2)

Input

PNP switch

Accelerator pedal position signal

(*1)

Closed throttle position signal

(*1)

Engine speed signal

(*1)

CVT fluid temperature sensor

Second position switch signal

(*1)

Stop lamp switch signal

(*1)

Primary speed sensor

Secondary speed sensor

Primary pressure sensor

Secondary pressure sensor

TCM power supply voltage signal

Out-
put

Step motor

TCC solenoid valve

Lock-up select solenoid valve

Line pressure solenoid valve

Secondary pressure solenoid valve

SCIA1846E

CVT SYSTEM

CVT-41

CVT

Revision; 2004 April

2003 Murano

NORMAL CONTROL

Optimize the line pressure and secondary pressure, depending on driving conditions, on the basis of the throt-
tle position, the engine speed, the primary pulley (input) revolution speed, the secondary pulley (output) revo-
lution speed, the brake signal, the PNP switch signal, the lock-up signal, the voltage, the target gear ratio, the
fluid temperature, and the fluid pressure.

FEEDBACK CONTROL

When controlling the normal fluid pressure or the selected fluid pressure, the secondary pressure can be set
more accurately by using the fluid pressure sensor to detect the secondary pressure and controlling the feed-
back.

Shift Control

ACS0020L

In order to select the gear ratio which can obtain the driving force in accordance with driver's intention and the
vehicle condition, monitor the driving conditions, such as the vehicle speed and the throttle position, select the
appropriate gear ratio, and determine how to change the gear before reaching it in the TCM. Then send the
command to the step motor, and control the flow-in/flow-out of line pressure from the primary pulley to deter-
mine the position of the moving-pulley and control the gear ratio.

NOTE:
The gear ratio is set for every position separately.

“D” POSITION

Shifting over all the ranges of gear ratios from the lowest to the high-
est.

“S”POSITION

Use this position for the improved engine braking.

SCIA1952E

SCIA1953E

CVT-42

CVT SYSTEM

Revision; 2004 April

2003 Murano

“L” POSITION

By limiting the gear range to the lowest position, the strong driving
force and the engine brake can be secured.

DOWNHILL ENGINE BRAKE CONTROL (AUTO ENGINE BRAKE CONTROL)

When downhill is detected with the accelerator pedal released, the engine brake will be strengthened up by
downshifting so as not to accelerate the vehicle more than necessary.

KICKDOWN CONTROL

During sudden deceleration, determine if it is a sudden deceleration from the throttle position to secure the
highly responsive driving force as necessary. When it is judged as sudden deceleration, speed up the shift pat-
tern faster than normal depression for a certain period of time, and slowly shift gears to get highly responsive
shift pattern.

Lock-Up and Select Control

ACS002S9

●

The torque converter clutch piston in the torque converter is engaged to eliminate torque converter slip to
increase power transmission efficiency.

●

The torque converter clutch control valve operation is controlled by the torque converter clutch solenoid
valve, which is controlled by a signal from TCM. The torque converter clutch control valve engages or
releases the torque converter clutch piston.

●

When shifting between N (P) &iff; D (R), torque converter clutch solenoid controls engagement power of
forward clutch and reverse brake.

●

The lock-up applied gear range was expanded by locking up the
torque converter at a lower vehicle speed than conventional
CVT models.

SCIA1955E

SCIA1958E

CVT SYSTEM

CVT-43

CVT

Revision; 2004 April

2003 Murano

TORQUE CONVERTER CLUTCH AND SELECT CONTROL VALVE CONTROL
Lock-Up and Select Control System Diagram

Lock-Up Released

●

In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the
torque converter clutch solenoid and the lock-up apply pressure is drained.
In this way, the torque converter clutch piston is not coupled.

Lock-Up Applied

●

In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the
torque converter clutch solenoid and lock-up apply pressure is generated.
In this way, the torque converter clutch piston is pressed and coupled.

Select Control

●

When shifting between N (P)

⇔

D (R), optimize the operating pressure on the basis of the throttle position,

the engine speed, and the secondary pulley (output) revolution speed to lessen the shift shock.

●

Switch lock-up control or select control with torque converter clutch solenoid valve to switching select
valve switch with lock-up select solenoid valve.

SCIA2374E

CVT-44

CVT SYSTEM

Revision; 2004 April

2003 Murano

Control Valve

ACS002S8

FUNCTION OF CONTROL VALVE

Name

Function

Torque converter regulator valve

Optimize the supply pressure for the torque converter depending on driving conditions.

Pressure regulator valve

Optimize the discharge pressure from the oil pump depending on driving conditions.

TCC control valve

●

Activate or deactivate the lock-up.

●

Lock-up smoothly by opening lock-up operation excessively.

TCC solenoid valve

Controls the TCC control valve or select control valve.

Shift control valve

Controls flow-in/out of line pressure from the primary pulley depending on the stroke dif-
ference between the stepping motor and the primary pulley.

Secondary valve

Controls the line pressure from the secondary pulley depending on operating condi-
tions.

Clutch regulator valve

Adjust the clutch operating pressure depending on operating conditions.

Secondary pressure solenoid valve

Controls the secondary valve.

Line pressure solenoid valve

Controls the line pressure control valve.

Step motor

Controls the pulley ratio.

Manual valve

Transmit the clutch operating pressure to each circuit in accordance with the selected
position.

Select control valve

Engage forward clutch, reverse brake smoothly depending on select operation.

Select switch valve

Switch torque converter clutch solenoid valve control pressure use to torque converter
clutch control valve or select control valve.

Lock-up select solenoid valve

Controls the select switch valve.

ON BOARD DIAGNOSTIC (OBD) SYSTEM

CVT-45

CVT

Revision; 2004 April

2003 Murano

ON BOARD DIAGNOSTIC (OBD) SYSTEM

PFP:00028

Introduction

ACS001SS

The CVT system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (OBD-II) performed by the TCM in combination
with the ECM. The malfunction is indicated by the MIL (malfunction indicator lamp) and is stored as a DTC in
the ECM memory, and the TCM memory.
The second is the TCM original self-diagnosis performed by the TCM. The malfunction is stored in the TCM
memory. The detected items are overlapped with OBD-II self-diagnostic items. For detail, refer to

CVT-71,

"Self-Diagnostic Result Test Mode"

OBD-II Function for CVT System

ACS001ST

The ECM provides emission-related on board diagnostic (OBD-II) functions for the CVT system. One function
is to receive a signal from the TCM used with OBD-related parts of the CVT system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-related part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indicator lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in relation
to CVT system parts.

One or Two Trip Detection Logic of OBD-II

ACS001SU

ONE TRIP DETECTION LOGIC

If a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.

TWO TRIP DETECTION LOGIC

When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. — First Trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MIL will illuminate. — Second Trip
The “trip” in the “One or Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation.

OBD-II Diagnostic Trouble Code (DTC)

ACS001SV

HOW TO READ DTC AND 1ST TRIP DTC

DTC and 1st trip DTC can be read by the following methods.
(

with CONSULT-II or

GST) CONSULT-II or GST (Generic Scan Tool) Examples: P0705, P0720 etc.

These DTC are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)

●

1st trip DTC No. is the same as DTC No.

●

Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST, they do not indicate whether the malfunction is still occurring
or occurred in the past and returned to normal.
CONSULT-II can identify them as shown below, therefore, CONSULT-II (if available) is recom-
mended.

A sample of CONSULT-II display for DTC and 1st trip DTC is shown
on the next page. DTC or 1st trip DTC of a malfunction is displayed
in SELF-DIAGNOSTIC RESULTS mode for “ENGINE” with CON-
SULT-II. Time data indicates how many times the vehicle was driven
after the last detection of a DTC.

SCIA2272E

CVT-46

ON BOARD DIAGNOSTIC (OBD) SYSTEM

Revision; 2004 April

2003 Murano

If the DTC is being detected currently, the time data will be “0”.

If a 1st trip DTC is stored in the ECM, the time data will be “1t”.

Freeze Frame Data and 1st Trip Freeze Frame Data

The ECM has a memory function, which stores the driving condition such as fuel system status, calculated
load value, engine coolant temperature, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II
or GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
details, refer to

EC-125, "CONSULT-II Function"

Only one set of freeze frame data (either 1st trip freeze frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data, and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.

Both 1st trip freeze frame data and freeze frame data (along with the DTC) are cleared when the ECM mem-
ory is erased.

HOW TO ERASE DTC

The diagnostic trouble code can be erased by CONSULT-II, GST or ECM DIAGNOSTIC TEST MODE as
described following.

●

If the battery cable is disconnected, the diagnostic trouble code will be lost within 24 hours.

●

When you erase the DTC, using CONSULT-II or GST is easier and quicker than switching the mode
selector on the ECM.

The following emission-related diagnostic information is cleared from the ECM memory when erasing DTC
related to OBD-II. For details, refer to

EC-69, "Emission-related Diagnostic Information"

●

Diagnostic trouble codes (DTC)

●

1st trip diagnostic trouble codes (1st trip DTC)

●

Freeze frame data

SAT015K

SAT016K

Priority

Items

Freeze frame data

Misfire — DTC: P0300 - P0306
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175

Except the above items (Includes CVT related items)

1st trip freeze frame data

ON BOARD DIAGNOSTIC (OBD) SYSTEM

CVT-47

CVT

Revision; 2004 April

2003 Murano

●

1st trip freeze frame data

●

System readiness test (SRT) codes

●

Test values

HOW TO ERASE DTC (WITH CONSULT-II)

●

If a DTC is displayed for both ECM and TCM, it is necessary to be erased for both ECM and TCM.

If the ignition switch stays “ON” after repair work, be sure to turn ignition switch “OFF” once. Wait at least
10 seconds and then turn it “ON” (engine stopped) again.

Turn CONSULT-II “ON” and touch “TRANSMISSION”.

Touch “SELF-DIAG RESULTS”.

Touch “ERASE”. (The DTC in the TCM will be erased.) Then touch “BACK” twice.

Touch “ENGINE”.

Touch “SELF-DIAG RESULTS”.

Touch “ERASE”. (The DTC in the ECM will be erased.)

HOW TO ERASE DTC (WITH GST)

If the ignition switch stays “ON” after repair work, be sure to turn ignition switch “OFF” once. Wait at least
10 seconds and then turn it “ON” (engine stopped) again.

Select Mode 4 with Generic Scan Tool (GST). For details, refer to

EC-138, "Generic Scan Tool (GST)

Function"

SCIA5768E

Nissan Murano Z50 (2003 year). Manual - part 62