sensor NISSAN LATIO 2008 Service Repair Manual

TROUBLE DIAGNOSIS
CVT-29
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TROUBLE DIAGNOSIS
DTC Inspection Priority ChartINFOID:0000000001703451
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-56
.
Fail-SafeINFOID:0000000001703452
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 overdrive-off mode is inhibited, and the tran-
saxle 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 sport mode
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”.
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 3500
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, secondary
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.
Ste p M oto r
If an unexpected signal is sent from the step motor to the TCM, the step motor coil phases “A” through “D” are
all turned OFF to hold the gear ratio used right before the non-standard condition occurred.
CVT Lock-up Select Solenoid
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above

CVT-30
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
If an unexpected signal is sent from the solenoid to the TCM, the CVT lock-up select solenoid is turned OFF to
cancel the lock-up.
TCM Power Supply (Memory Back-up)
Transaxle assembly is protected by limiting the engine torque when the memory back-up power supply (for
controlling) from the battery is not supplied to TCM. Normal statues is restored when turning the ignition switch
OFF to ON after the normal power supply.
How to Perform Trouble Diagnosis for Quick and Accurate RepairINFOID:0000000001703453
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, PNP switch and provides shift control or lock-up
control via CVT solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used with the OBD-related parts of the
CVT system for malfunction-diagnostic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions in its memory.
Input and output signals must always be correct and stable in the
operation of the CVT system. The CVT system must be in good
operating condition and be free of valve seizure, solenoid valve mal-
function, etc.
It is much more difficult to diagnose an error that occurs intermit-
tently rather than continuously. Most intermittent errors are caused
by poor electric connections or improper wiring. In this case, careful
checking of suspected circuits may help prevent the replacement of
good parts.
A visual check only may not find the cause of the errors. A road test
with CONSULT-III (or GST) or a circuit tester connected should be
performed. Follow the "WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “DIAGNOSTIC WORKSHEET” as
shown on the example (Refer to "Diagnostic Worksheet Chart" )
should be used.
Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.
WORK FLOW
A good understanding of the malfunction conditions can make troubleshooting faster and more accurate.
In general, each customer feels differently about a malfunction. It is important to fully understand the symp-
toms or conditions for a customer complaint.
Make good use of the two sheets provided, "Information From Customer" and "Diagnostic Worksheet Chart" ,
to perform the best troubleshooting possible.
Work Flow Chart
SAT631IB
SAT632I
SEF234G

TROUBLE DIAGNOSIS
CVT-35
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CVT Electrical Parts LocationINFOID:0000000001703454
1. O/D OFF indicator lamp 2. Shift position indicator 3. Accelerator pedal position sensor
4. CVT unit harness connector 5. Fuel door release 6. TCM
7. Overdrive control switch
BCIA0033E

CVT-40
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Road Test
INFOID:0000000001703457
DESCRIPTION
• The purpose of the test is to determine overall performance of CVT
and analyze causes of problems.
• The road test consists of the following three parts:
1. “Check Before Engine Is Started”CVT-41
.
2. “Check at Idle”CVT-41
.
3. “Cruise Test”CVT-43
.
Judgement Possible cause
Idle speedLow for all positions
(“P”, “R”, “N”, “D”, “L”)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 specific
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
function.
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
Sta ll sp ee dLine pressure does
not rise higher than
the line pressure for
idle.Possible causes include a sensor malfunction or malfunction in the pressure adjustment func-
tion.
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 position.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 specific
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.
SAT786A

CVT-46
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
4BRLock-up select
solenoid valveSelector lever in “P” and “N” positions Battery voltage
Wait at least for 5 seconds with the selector lever in
“R”, “D” and “L” positions0 V
5 L CAN-H — —
6 P CAN-L — —
8VBack-up lamp
relaySelector lever in “R” position. 0 V
Selector lever in other positions. Battery voltage
10 R Power supply— Battery voltage
—0 V
11 L Step motor A Within 2 seconds after ignition switch ON, the time measurement by using
the pulse width measurement function (Hi level) of CONSULT-III.*1
*1: A circuit tester cannot be used to test this item.30.0 msec
12 Y Step motor B10.0 msec
13 G ROM assembly — —
14 Y ROM assembly — —
15 G ROM assembly — —
19 R Power supply— Battery voltage
—0 V
20 W Step motor C Within 2 seconds after ignition switch ON, the time measurement by using
the pulse width measurement function (Hi level) of CONSULT-III.*1
*1: A circuit tester cannot be used to test this item.30.0 msec
21 P Step motor D10.0 msec
24 BR Starter relaySelector lever in “N” and “P”positions. Battery voltage
Selector lever in other positions. 0 V
25 B Ground Always 0 V
27 GR PNP switch 1Selector lever in “R”, “N” and “D” positions. 0 V
Selector lever in “P” and “L” positions. Battery voltage
28 YPower supply
(memory back-
up)Always Battery voltage
29 ROutput speed
sensor (Second-
ary speed sen-
sor)When driving [“D” position, 20 km/h (12 MPH)]. 570 Hz
31 LG K-LINE — — Te r m i n a lWire
colorItem Condition Data (Approx.)

TROUBLE DIAGNOSIS
CVT-47
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CONSULT-III Function (TRANSMISSION)INFOID:0000000001703463
CONSULT-III can display each diagnostic item using the diagnostic test modes shown below.
FUNCTION
32 YPNP switch 3
(monitor)Selector lever in “D” and “L” positions. 0 V
Selector lever in “P”, “R” and “N” positions.8.0 V - Battery
voltage
34 SB PNP switch 2Selector lever in “N”, “D” and “L” positions. 0 V
Selector lever in “P” and “R” positions.10.0 V - Battery
voltage
35 W PNP switch 3Selector lever in “D” and “L” positions. 0 V
Selector lever in “P”, “R” and “N” positions.8.0 V - Battery
voltage
36 W PNP switch 4Selector lever in “R” and “D” positions. 0 V
Selector lever in “P”, “N” and “L” positions.10.0 V - Battery
voltage
37 LTransmission
fluid pressure
sensor A (Sec-
ondary pressure
sensor)and “N” position idle 1.0 V
38 VInput speed sen-
sor (Primary
speed sensor)When driving [“L” position, 20 km/h (12 MPH)]. 1000 Hz
41 GTransmission
fluid pressure
sensor B (Prima-
ry pressure sen-
sor)and “N” position idle 0.7 V
42 LG Sensor ground Always 0 V
46 O Sensor power— 5.0 V
— 0 V
47 GCVT fluid tem-
perature 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 Te r m i n a lWire
colorItem Condition Data (Approx.)
Diagnostic test mode Function
Work supportThis mode enables a technician to adjust some devices faster and more accurately by following the in-
dications on CONSULT-III.
Self-diagnostic results Self-diagnostic results can be read and erased quickly.
Data monitor Input/Output data in the TCM can be read.

CVT-48
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
CONSULT-III REFERENCE VALUE
CAN diagnostic support mon-
itorThe results of transmit/receive diagnosis of CAN communication can be read.
CALIB data Characteristic information for TCM and CVT assembly can be read.
Function test Performed by CONSULT-III instead of a technician to determine whether each system is “OK” or “NG”.
ECU part number TCM part number can be read.Diagnostic test mode Function
Item name Condition Display value (Approx.)
VSP SENSOR
During drivingApproximately matches the speedometer
reading.
ESTM VSP SIG*
PRI SPEED SEN During driving (lock-up ON) Approximately matches the engine speed.
ENG SPEED SIG Engine running Closely matches the tachometer reading.
SEC HYDR SEN “N” position idle 1.0 V
PRI HYDR SEN “N” position idle 0.7 V
ATF TEMP SENWhen CVT fluid temperature is 20°C (68°F). 2.0 V
When CVT fluid temperature is 80°C (176°F). 1.0 V
VIGN SEN Ignition switch: ON Battery voltage
VEHICLE SPEED During drivingApproximately matches the speedometer
reading.
PRI SPEED During driving (lock-up ON) Approximately matches the engine speed.
SEC SPEED During driving50 X Approximately matches the speedom-
eter reading.
ENG SPEED Engine running Closely matches the tachometer reading.
GEAR RATIO During driving 2.56 - 0.43
ACC PEDAL OPENReleased accelerator pedal - Fully depressed
accelerator pedal0.0/8 - 8.0/8
SEC PRESS “N” position idle 0.8 MPa
PRI PRESS “N” position idle 0.4 MPa
STM STEP During driving−20 step - 180 step
ISOLT1Lock-up OFF 0.0 A
Lock-up ON 0.7 A
ISOLT2Release your foot from the accelerator pedal. 0.8 A
Press the accelerator pedal all the way down. 0.0 A
ISOLT3Secondary pressure low - Secondary pressure
high.0.8 - 0.0 A
SOLMON1Lock-up OFF 0.0 A
Lock-up ON 0.7 A
SOLMON2“N” position idle 0.8 A
When stalled 0.3 - 0.6 A
SOLMON3“N” position idle 0.6 - 0.7 A
When stalled 0.4 - 0.6 A
INH SW3MSelector lever in “D” and “L” positions ON
Selector lever in “P”, “R” and “N” positions OFF
INH SW4Selector lever in “R” and “D” positions ON
Selector lever in “P”, “N” and “L” positions OFF

CVT-50
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Engine Brake Adjustment
CAUTION:
Mode of “+1”“0”“-1”“-2”“OFF” can be selected by pressing the “UP”“DOWN” on CONSULT-III screen.
However, do not select mode other than “0” and “OFF”. If the “+1” or “-1” or “-2” is selected, that
might cause the irregular driveability.
Check CVT Fluid Deterioration Date
CAUTION:
Touch “CLEAR” after changing CVT fluid, and then erase “CVTF DETERIORATION DATE”.
SELF-DIAGNOSTIC RESULT MODE
After performing self-diagnosis, place check marks for results on the CVT-30, "How to Perform Trouble Diag-
nosis for Quick and Accurate Repair" . Reference pages are provided following the items.
Display Items List
X: Applicable —: Not applicable
Item name Description
ENGINE BRAKE ADJ. The engine brake level setting can be canceled.
CONFORM CVTF DETERIORTN The CVT fluid deterioration level can be checked.
“ENGINE BRAKE LEVEL”
0: Initial set value (Engine brake level control is ac-
tivated)
OFF: Engine brake level control is deactivated.
“CVTF DETERIORATION DATE”
More than 210000:
It is necessary to change CVT fluid.
Less than 210000:
It is not necessary to change CVT fluid.
Items (CONSULT-
III screen terms)Malfunction is detected when...TCM self-di-
agnosisOBD-III (DTC)
Reference
page “TRANSMIS-
SION” with
CONSULT-IIIMIL indicator
lamp*1, “EN-
GINE” with
CONSULT-III
or GST
CAN COMM CIR-
CUITWhen TCM is not transmitting or receiving CAN communica-
tion signal for 2 seconds or moreU1000 U1000CVT-56
CONTROL
UNIT(CAN)When detecting error during the initial diagnosis of CAN con-
troller of TCMU1010 U1010CVT-59
STARTER RELAY/
CIRCIf this signal is ON other than in “P” or “N” position, this is
judged to be a malfunction
(And if it is OFF in “P” or “N” position, this is judged to be a
malfunction too)P0615 —CVT-60
BRAKE SW/CIRC When the brake switch does not switch to ON or OFF P0703 —CVT-63
PNP SW/CIRC• PNP switch 1-4 signals input with impossible pattern
• PNP switch 3 monitor terminal open or short circuitP0705 P0705CVT-65
ATF TEMP SEN/
CIRCDuring running, the CVT fluid temperature sensor signal volt-
age is excessively high or lowP0710 P0710CVT-71
INPUT SPD SEN/
CIRC• Input speed sensor (primary speed sensor) signal is not in-
put due to an open circuit
• An unexpected signal is input when vehicle is being drivenP0715 P0715CVT-76

TROUBLE DIAGNOSIS
CVT-51
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PVEH SPD SEN/
CIR AT• Signal from vehicle speed sensor CVT [Output speed sen-
sor (Secondary speed sensor)] not input due to open or
short circuit
• Unexpected signal input during runningP0720 P0720CVT-80
ENGINE SPEED
SIG• TCM does not receive the CAN communication signal from
the ECM
• Engine speed is too low while drivingP0725 —CVT-85
BELT DAMG Unexpected gear ratio detected P0730 —CVT-87
TCC SOLENOID/
CIRCNormal voltage not applied to solenoid due to open or short
circuitP0740 P0740CVT-88
A/T TCC S/V
FNCTN• CVT cannot perform lock-up even if electrical circuit is good
• TCM detects as irregular by comparing difference value
with slip rotation
• There is big difference engine speed and primary speed
when TCM lock-up signal is onP0744 P0744CVT-93
L/PRESS SOL/
CIRC• Normal voltage not applied to solenoid due to open or short
circuit
• TCM detects as irregular by comparing target value with
monitor valueP0745 P0745CVT-95
PRS CNT SOL/A
FCTNUnexpected gear ratio was detected in the LOW side due to
excessively low line pressureP0746 P0746CVT-100
PRS CNT SOL/B
FCTNSecondary pressure is too high or too low compared with the
commanded value while drivingP0776 P0776CVT-102
PRS CNT SOL/B
CIRC• Normal voltage not applied to solenoid due to cut line,
short, or the like
• TCM detects as irregular by comparing target value with
monitor valueP0778 P0778CVT-104
TR PRS SENS/A
CIRCSignal voltage of the transmission fluid pressure sensor A
(secondary pressure sensor) is too high or too low while driv-
ingP0840 P0840CVT-109
PRESS SEN/
FNCTNCorrelation between the values of the transmission fluid pres-
sure sensor A (secondary pressure sensor) and the transmis-
sion fluid pressure sensor B (primary pressure sensor) is out
of specificationP0841 —CVT-113
TR PRS SENS/B
CIRCSignal voltage of the transmission fluid pressure sensor B
(primary pressure sensor) is too high or too low while drivingP0845 P0845CVT-115
SEC/PRESS
DOWNSecondary fluid pressure is too low compared with the com-
manded value while drivingP0868 —CVT-119
TCM-POWER
SUPPLY• When the power supply to the TCM is cut OFF, for example
because the battery is removed, and the self-diagnosis
memory function stops
• This is not a malfunction message (Whenever shutting
OFF a power supply to the TCM, this message appears on
the screen)P1701 —CVT-121
TP SEN/CIRC A/TTCM does not receive the proper accelerator pedal position
signals (input by CAN communication) from ECMP1705 —CVT-125
ESTM VEH SPD
SIG*2• CAN communication with the ABS actuator and the electric
unit (control unit) is malfunctioning
• There is a great difference between the vehicle speed sig-
nal from the ABS actuator and the electric unit (control
unit), and the vehicle speed sensor signalP1722 —CVT-127
Items (CONSULT-
III screen terms)Malfunction is detected when...TCM self-di-
agnosisOBD-III (DTC)
Reference
page “TRANSMIS-
SION” with
CONSULT-IIIMIL indicator
lamp*1, “EN-
GINE” with
CONSULT-III
or GST

CVT-52
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
*1: Refer to CVT-27, "Malfunction Indicator Lamp (MIL)" .
*2: Models without ABS does not indicate.
DATA MONITOR MODE
Display Items List
X: Standard, —: Not applicable, : Option
CVT SPD SEN/
FNCTNA rotation sensor error is detected because the gear does not
change in accordance with the position of the stepping motor
CAUTION:
One of the “P0720 VEH SPD SEN/CIR AT”, the “P0715 IN-
PUT SPD SEN/CIRC” or the “P0725 ENGINE SPEED SIG“
is displayed with the DTC at the same timeP1723 —CVT-129
ELEC TH CON-
TROLThe electronically controlled throttle for ECM is malfunction-
ingP1726 —CVT-131
LU-SLCT SOL/
CIRC• Normal voltage not applied to solenoid due to cut line,
short, or the like
• TCM detects as irregular by comparing target value with
monitor valueP1740 P1740CVT-132
L/PRESS CON-
TROLTCM detects the unexpected line pressure P1745 —CVT-136
STEP MOTR CIRCEach coil of the step motor is not energized properly due to
an open or a shortP1777 P1777CVT-137
STEP MOTR/FNCThere is a great difference between the number of steps for
the stepping motor and for the actual gear ratioP1778 P1778CVT-141
NO DTC IS DE-
TECTED: FUR-
THER TESTING
MAY BE RE-
QUIREDNo NG item has been detected X X — Items (CONSULT-
III screen terms)Malfunction is detected when...TCM self-di-
agnosisOBD-III (DTC)
Reference
page “TRANSMIS-
SION” with
CONSULT-IIIMIL indicator
lamp*1, “EN-
GINE” with
CONSULT-III
or GST
Monitored item (Unit)Monitor item selection
Remarks ECU IN-
PUT SIG-
NALSMAIN SIG-
NALSSELEC-
TION
FROM
MENU
VSP SENSOR (km/h) X — Output speed sensor (secondary speed sensor).
ESTM VSP SIG (km/h) X — Models without ABS does not indicate.
PRI SPEED SEN (rpm) X —
ENG SPEED SIG (rpm) X —
SEC HYDR SEN (V) X —
PRI HYDR SEN (V) X —
ATF TEMP SEN (V) X — CVT fluid temperature sensor
VIGN SEN (V) X —
VEHICLE SPEED (km/h) — X Vehicle speed recognized by the TCM.
PRI SPEED (rpm) — X Primary pulley speed.
SEC SPEED (rpm) — — Secondary pulley speed.