2008 NISSAN LATIO service

CVT-28
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON with-
out the engine running. This is a bulb check.
• If the MIL does not light up, refer to DI-21
, or see EC-546.
2. When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction.
SEF217U

TROUBLE DIAGNOSIS
CVT-29
< SERVICE INFORMATION >
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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-31
< SERVICE INFORMATION >
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DIAGNOSTIC WORKSHEET
Information From Customer
KEY POINTS•WHAT..... Vehicle & CVT model
•WHEN..... Date, Frequencies
•WHERE..... Road conditions
•HOW..... Operating conditions, Symptoms
*1. "Information From Customer" *2. "DIAGNOSTIC WORKSHEET" *3.CVT-29
*4.CVT-36*5.CVT-36, CVT-36*6.CVT-40
*7.CVT-47*8.CVT-26*9.CVT-29
*10.CVT-56*11.CVT-141*12.CVT-149
*13.CVT-26*14.CVT-56*15.CVT-141
*16.EC-47
AWDIA0189GB

CVT-32
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Diagnostic Worksheet Chart
Customer name MR/MS Model & Year VIN
Trans. Model Engine Mileage
malfunction Date Manuf. Date In Service Date
Frequency❏ Continuous❏ Intermittent ( times a day)
Symptoms❏ Vehicle does not move. (❏ Any position❏ Particular position)
❏ No shift
❏ Lock-up malfunction
❏ Shift shock or slip (❏ N → D❏ N → R❏ Lock-up❏ Any drive position)
❏ Noise or vibration
❏ No pattern select
❏ Others
()
Malfunction indicator lamp (MIL)❏ Continuously lit❏ Not lit
1❏ Read the item on cautions concerning fail-safe and understand the customer's complaint.CVT-29
2❏ CVT fluid inspection
CVT-36❏ Leak (Repair leak location.)
❏ Sta te
❏ Amount
3❏ Stall test and line pressure test
CVT-36
,
CVT-36
❏ Stall test
❏ Torque converter one-way clutch
❏ Reverse brake
❏ Forward clutch
❏ Steel belt❏ Engine
❏ Line pressure low
❏ Primary pulley
❏ Secondary pulley
❏ Line pressure inspection - Suspected part:

TROUBLE DIAGNOSIS
CVT-33
< SERVICE INFORMATION >
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4❏ Perform road test.CVT-40
4-1.Check before engine is started CVT-41
❏CVT-151, "O/D OFF Indicator Lamp Does Not Come On"
❏ Perform self-diagnosis. Enter checks for detected items. CVT-47
❏CVT-56
❏CVT-60
❏CVT-63
❏CVT-65
❏CVT-71
❏CVT-76
❏CVT-80
❏CVT-85
❏CVT-87
❏CVT-88
❏CVT-93
❏CVT-95
❏CVT-100
❏CVT-102
❏CVT-104
❏CVT-109
❏CVT-113
❏CVT-115
❏CVT-119
❏CVT-121
❏CVT-125
❏CVT-127
❏CVT-129
❏CVT-131
❏CVT-132
❏CVT-137
❏CVT-141
4-2.Check at idleCVT-41
❏CVT-153, "Engine Cannot Be Started in "P" and "N" Position"
❏CVT-153, "In "P" Position, Vehicle Moves Forward or Backward When Pushed"
❏CVT-154, "In "N" Position, Vehicle Moves"
❏CVT-154, "Large Shock "N" → "R" Position"
❏CVT-155, "Vehicle Does Not Creep Backward in "R" Position"
❏CVT-156, "Vehicle Does Not Creep Forward in "D" or "L" Position"

CVT-34
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
44-3.Cruise testCVT-43
❏CVT-157, "Vehicle Speed Does Not Change in "L" Position"
❏CVT-158, "Vehicle Speed Does Not Change in overdrive-off mode"
❏CVT-159, "Vehicle Speed Does Not Change in "D" Position"
❏CVT-159, "Vehicle Does Not Decelerate by Engine Brake"
❏ perform self-diagnosis. Enter checks for detected items. CVT-47
❏CVT-56
❏CVT-60
❏CVT-63
❏CVT-65
❏CVT-71
❏CVT-76
❏CVT-80
❏CVT-85
❏CVT-87
❏CVT-88
❏CVT-93
❏CVT-95
❏CVT-100
❏CVT-102
❏CVT-104
❏CVT-109
❏CVT-113
❏CVT-115
❏CVT-119
❏CVT-121
❏CVT-125
❏CVT-127
❏CVT-129
❏CVT-131
❏CVT-132
❏CVT-137
❏CVT-141
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 items.CVT-40
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 TCM.CVT-26
,
CVT-26

TROUBLE DIAGNOSIS
CVT-35
< SERVICE INFORMATION >
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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