2003 NISSAN TEANA Temperature sensor

CVT-18
CVT SYSTEM

TCM FunctionBCS001G2
The function of the TCM is to:

Receive input signals sent from various switches and sensors.

Determine required line pressure, shifting point, and lock-up operation.

Send required output signals to the step motor and the respective solenoids.
CONTROL SYSTEM OUTLINE
The CVT senses vehicle operating conditions through various sensors. It always controls the optimum shift
position and reduces shifting and lock-up shocks.
CONTROL SYSTEM DIAGRAM
SENSORS (or SIGNAL)

TCM

ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Engine speed signal
CVT fluid temperature sensor
Vehicle speed signal
Manual mode signal
Stop lamp switch signal
Primary speed sensor
Secondary speed sensor
Primary pressure sensor
Secondary pressure sensorShift control
Line pressure control
Primary pressure control
Secondary pressure control
Lock-up control
Engine brake control
Vehicle speed control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
Duet-EA control
CAN systemSte p mo tor
Torque converter clutch solenoid
valve
Lock-up select solenoid valve
Line pressure solenoid valve
Secondary pressure solenoid
valve
Manual mode indicator
Shift position indicator
CVT indicator lamp
Starter relay
SCIA7872E

CVT SYSTEM
CVT-19
D
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CVT

CAN CommunicationBCS001G3
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. For details, refer to LAN-49,
"CAN System Specification Chart" .
Input/Output Signal of TCMBCS001G4
*1: Input by CAN communications.
*2: If these input and output signals are different, the TCM triggers the fail-safe function. Control item Fluid
pressure
control Select
control Shift con-
trol Lock-up
control CAN com-
munication
control Fail-safe
function
(*2)
Input PNP switch XXXXXX
Accelerator pedal position signal
(*1)XXXXXX
Closed throttle position signal
(*1)XXXX
Engine speed signal
(*1)XX XXX
CVT fluid temperature sensor X X X X X
Manual mode signal
(*1)XXXXX
Stop lamp switch signal
(*1)XXXX
Primary speed sensor X X X X X
Secondary speed sensor X X X X X X
Primary pressure sensor X X
Secondary pressure sensor X X X
TCM power supply voltage signal X X X X X X
Out-
put Step motor X X
TCC solenoid valve X X X
Lock-up select solenoid valve X X X
Line pressure solenoid valve X X X X
Secondary pressure solenoid valve X X X

CVT-20
CVT SYSTEM

Line Pressure and Secondary Pressure ControlBCS001G5

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 controlled by decreasing line pressure.
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 ControlBCS001G6
In order to select the gear ratio which can obtain the driving force in accordance with driver's intention and the
vehicle condition, TCM monitors the driving conditions, such as the vehicle speed and the throttle position and
selects the optimum gear ratio, and determines the gear change steps to the gear ratio. Then send the com-
mand to the step motor, and control the flow-in/flow-out of line pressure from the primary pulley to determine
the position of the moving-pulley and control the gear ratio.
SCIA1846E
SCIA6581E

CVT-24
TROUBLE DIAGNOSIS

TROUBLE DIAGNOSISPFP:00004
DTC Inspection Priority ChartBCS001GE
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC “U1000 CAN COMM CIRCUIT” is displayed with other DTCs, first perform the trouble diagnosis
for “DTC U1000 CAN COMMUNICATION LINE”. Refer to CVT-53
.
Fail-safeBCS001GF
The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is an error in a
main electronic control input/output signal circuit.
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, this function controls the CVT to make driving possible.
Output Speed Sensor (Secondary Speed Sensor)
The shift pattern is changed in accordance with throttle position when an unexpected signal is sent from the
output speed sensor (secondary speed sensor) to the TCM. The manual mode position and second position is
inhibited, and the transaxle is put in “D”.
Input Speed Sensor (Primary Speed Sensor)
The shift pattern is changed in accordance with throttle position and secondary speed (vehicle speed) when
an unexpected signal is sent from the input speed sensor (primary speed sensor) to the TCM. The manual
mode position and second position is inhibited, and the transaxle is put in “D”.
PNP Switch
If an unexpected signal is sent from the PNP switch to the TCM, the transaxle is put in “D”.
Manual Mode Switch
If an unexpected signal is sent from the manual mode switch to the TCM, the transaxle is put in “D”.
CVT Fluid Temperature Sensor
If an unexpected signal is sent from the CVT fluid temperature sensor to the TCM, the gear ratio in use before
receiving the unexpected signal is maintained or the gear ratio is controlled to keep engine speed under 5,000
rpm.
Transmission Fluid Pressure Sensor A (Secondary Pressure Sensor)

If an unexpected signal is sent from the transmission fluid pressure sensor A (secondary pressure sensor)
to the TCM, the secondary pressure feedback control is stopped and the offset value obtained before the
non-standard condition occurs is used to control line pressure.

If transmission fluid pressure sensor A (secondary pressure sensor) error signal is input to TCM, second-
ary pressure feedback control stops, but line pressure is controlled normally.
Pressure Control Solenoid A (Line Pressure Solenoid)
If an unexpected signal is sent from the solenoid to the TCM, the pressure control solenoid A (line pressure
solenoid) is turned OFF to achieve the maximum fluid pressure.
Pressure Control Solenoid B (Secondary Pressure Solenoid)
If an unexpected signal is sent from the solenoid to the TCM, the pressure control solenoid B (secondary pres-
sure solenoid) is turned OFF to achieve the maximum fluid pressure.
Torque Converter Clutch Solenoid
If an unexpected signal is sent from the solenoid to the TCM, the torque converter clutch solenoid is turned
OFF to cancel the lock-up.
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above

CVT-28
TROUBLE DIAGNOSIS

4❏ Perform road testCVT-35
4-1.Check before engine is started CVT-37
❏ CVT-164, "CVT Indicator Lamp Does Not Come On"
❏ Perform self-diagnosis. Enter checks for detected items. CVT-47
❏ CVT-53, "DTC U1000 CAN COMMUNICATION LINE"
❏ CVT-56, "DTC P0615 START SIGNAL CIRCUIT"
❏ CVT-60, "DTC P0703 STOP LAMP SWITCH CIRCUIT"
❏ CVT-62, "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
❏ CVT-69, "DTC P0710 CVT FLUID TEMPERATURE SENSOR CIRCUIT"
❏ CVT-74, "DTC P0715 INPUT SPEED SENSOR CIRCUIT (PRI SPEED SENSOR)"
❏ CVT-79, "DTC P0720 VEHICLE SPEED SENSOR CVT (SECONDARY SPEED SEN-
SOR)"
❏ CVT-85, "DTC P0725 ENGINE SPEED SIGNAL"
❏ CVT-87, "DTC P0730 BELT DAMAGE"
❏ CVT-89, "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
❏ CVT-94, "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
❏ CVT-97, "DTC P0745 LINE PRESSURE SOLENOID VALVE"
❏ CVT-102, "DTC P0746 PRESSURE CONTROL SOLENOID A PERFORMANCE
(LINE PRESSURE SOLENOID VALVE)"
❏ CVT-105, "DTC P0776 PRESSURE CONTROL SOLENOID B PERFORMANCE
(SEC PRESSURE SOLENOID VALVE)"
❏ CVT-108, "DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC
PRESSURE SOLENOID VALVE)"
❏ CVT-113, "DTC P0826 MANUAL MODE SWITCH CIRCUIT"
❏ CVT-118, "DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT
(SEC PRESSURE SENSOR)"
❏ CVT-123, "DTC P0841 PRESSURE SENSOR FUNCTION"
❏ CVT-126, "DTC P0845 TRANSMISSION FLUID PRESSURE SENSOR B CIRCUIT
(PRI PRESSURE SENSOR)"
❏ CVT-131, "DTC P0868 SECONDARY PRESSURE DOWN"
❏ CVT-134, "DTC P1701 TRANSMISSION CONTROL MODULE (POWER SUPPLY)"
❏ CVT-139, "DTC P1705 THROTTLE POSITION SENSOR"
❏ CVT-141, "DTC P1722 ESTM VEHICLE SPEED SIGNAL"
❏ CVT-143, "DTC P1723 CVT SPEED SENSOR FUNCTION"
❏ CVT-145, "DTC P1726 ELECTRIC THROTTLE CONTROL SYSTEM"
❏ CVT-147, "DTC P1740 LOCK-UP SELECT SOLENOID VALVE CIRCUIT"
❏ CVT-153, "DTC P1777 STEP MOTOR - CIRCUIT"
❏ CVT-157, "DTC P1778 STEP MOTOR - FUNCTION"
4-2.Check at idleCVT-37
❏ CVT-165, "Engine Cannot Be Started in “P” or “N” Position"
❏ CVT-166, "In “P” Position, Vehicle Moves Forward or Backward When Pushed"
❏ CVT-166, "In “N” Position, Vehicle Moves"
❏ CVT-167, "Large Shock “N” → “R” Position"
❏ CVT-168, "Vehicle Does Not Creep Backward in “R” Position"
❏ CVT-169, "Vehicle Does Not Creep Forward in “D” Position"

TROUBLE DIAGNOSIS
CVT-29
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CVT

44-3.Cruise testCVT-38
❏ CVT-170, "CVT Does Not Shift"
❏ CVT-171, "Cannot Be Changed to Manual Mode"
❏ CVT-171, "CVT Does Not Shift in Manual Mode"
❏ CVT-172, "Vehicle Does Not Decelerate by Engine Brake"
❏ Perform self-diagnosis. Enter checks for detected items. CVT-47
❏ CVT-53, "DTC U1000 CAN COMMUNICATION LINE"
❏ CVT-56, "DTC P0615 START SIGNAL CIRCUIT"
❏ CVT-60, "DTC P0703 STOP LAMP SWITCH CIRCUIT"
❏ CVT-62, "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
❏ CVT-69, "DTC P0710 CVT FLUID TEMPERATURE SENSOR CIRCUIT"
❏ CVT-74, "DTC P0715 INPUT SPEED SENSOR CIRCUIT (PRI SPEED SENSOR)"
❏ CVT-79, "DTC P0720 VEHICLE SPEED SENSOR CVT (SECONDARY SPEED SEN-
SOR)"
❏ CVT-85, "DTC P0725 ENGINE SPEED SIGNAL"
❏ CVT-87, "DTC P0730 BELT DAMAGE"
❏ CVT-89, "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
❏ CVT-94, "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
❏ CVT-97, "DTC P0745 LINE PRESSURE SOLENOID VALVE"
❏ CVT-102, "DTC P0746 PRESSURE CONTROL SOLENOID A PERFORMANCE
(LINE PRESSURE SOLENOID VALVE)"
❏ CVT-105, "DTC P0776 PRESSURE CONTROL SOLENOID B PERFORMANCE
(SEC PRESSURE SOLENOID VALVE)"
❏ CVT-108, "DTC P0778 PRESSURE CONTROL SOLENOID B ELECTRICAL (SEC
PRESSURE SOLENOID VALVE)"
❏ CVT-113, "DTC P0826 MANUAL MODE SWITCH CIRCUIT"
❏ CVT-118, "DTC P0840 TRANSMISSION FLUID PRESSURE SENSOR A CIRCUIT
(SEC PRESSURE SENSOR)"
❏ CVT-123, "DTC P0841 PRESSURE SENSOR FUNCTION"
❏ CVT-126, "DTC P0845 TRANSMISSION FLUID PRESSURE SENSOR B CIRCUIT
(PRI PRESSURE SENSOR)"
❏ CVT-131, "DTC P0868 SECONDARY PRESSURE DOWN"
❏ CVT-134, "DTC P1701 TRANSMISSION CONTROL MODULE (POWER SUPPLY)"
❏ CVT-139, "DTC P1705 THROTTLE POSITION SENSOR"
❏ CVT-141, "DTC P1722 ESTM VEHICLE SPEED SIGNAL"
❏ CVT-143, "DTC P1723 CVT SPEED SENSOR FUNCTION"
❏ CVT-145, "DTC P1726 ELECTRIC THROTTLE CONTROL SYSTEM"
❏ CVT-147, "DTC P1740 LOCK-UP SELECT SOLENOID VALVE CIRCUIT"
❏ CVT-153, "DTC P1777 STEP MOTOR - CIRCUIT"
❏ CVT-157, "DTC P1778 STEP MOTOR - FUNCTION"
5❏ Inspect each system for items found to be NG in the self-diagnosis and repair or replace the malfunctioning parts
6❏ Perform all road tests and enter the checks again for the required itemsCVT-35
7❏ For any remaining NG items, perform the “diagnosis procedure” and repair or replace the malfunctioning parts
8❏ Erase the results of the self-diagnosis from the TCMCVT-49

CVT-34
TROUBLE DIAGNOSIS

5. Start the engine, and then measure the line pressure at idle
speed.
CAUTION:
Keep the brake pedal pressed all the way down during mea-
surement.
6. After the measurements are complete, install the oil pressure
detection plug and tighten to the specified torque below.
CAUTION:

Do not reuse O-ring.

Apply CVT fluid to O-ring.
Line Pressure
*1 : Reference values
Judgement of Line Pressure Test
: 7.5 N·m (0.77 kg-m, 66 in-lb)
SAT493G
Engine Engine speedLine pressure kPa (bar, kg/cm2 , psi)
“R”, “D” positions
VQ35DEAt idle speed 750 (7.50, 7.65, 108.8)
At stall speed
5,700 (57.00, 58.14, 826.5)*
1
Judgement Possible cause
Idle speedLow for all positions
(“P”, “R”, “N”, “D”)Possible causes include malfunctions in the pressure supply system and low oil pump output
For example

Oil pump wear

Pressure regulator valve or plug sticking or spring fatigue

Oil strainer
oil pump
pressure regulator valve passage oil leak

Engine idle speed too low
Only low for a spe-
cific positionPossible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve
HighPossible causes include a sensor malfunction or malfunction in the line pressure adjustment func-
tion
For example

Accelerator pedal position signal malfunction

CVT fluid temperature sensor malfunction

Pressure control solenoid A (line pressure solenoid) malfunction (sticking in “OFF” state, filter
clog, cut line)

Pressure regulator valve or plug sticking
Stall speedOil pressure does
not rise higher than
the oil pressure for
idle.Possible causes include a sensor malfunction or malfunction in the pressure adjustment function.
For example

Accelerator pedal position signal malfunction

TCM malfunction

Pressure control solenoid A (line pressure solenoid) malfunction (shorting, sticking in “ON”
state)

Pressure regulator valve or plug sticking
The pressure rises,
but does not enter
the standard posi-
tion.Possible causes include malfunctions in the pressure supply system and malfunction in the pres-
sure adjustment function
For example

Accelerator pedal position signal malfunction

Pressure control solenoid A (line pressure solenoid) malfunction (sticking, filter clog)

Pressure regulator valve or plug sticking
Only low for a spe-
cific positionPossible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve

CVT-42
TROUBLE DIAGNOSIS

37 V/WTransmission fluid
pressure sensor A
(Secondary pressure
sensor)and “N” position idle 1.0 V
38 LGInput speed sensor
(Primary speed sensor)When driving [“M1” position, 20 km/h (12 MPH)]. 700 Hz
41 V/OTransmission fluid
pressure sensor B (Pri-
mary pressure sensor)and “N” position idle 0.7 - 3.5 V
42 W/R Sensor ground Always 0 V
46 L/O Sensor power— 5.0 V
— 0 V
47 VCVT fluid temperature
sensor When CVT fluid temperature is 20°C (68°F) 2.0 V
When CVT fluid temperature is 80°C (176°F) 1.0 V
48 B Ground Always 0 V TerminalWire
colorItem Condition Data (Approx.)