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Home/Nissan/Sentra/Nissan Sentra B16 (2006-2009)/Repair manual/Automatic Trans/Continuously Variable Transmission (Cvt): Maintenance
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Continuously Variable Transmission (Cvt): Maintenance Nissan Sentra B16

Automatic Trans 14 illustrations ~1050 words

FLUID LEVEL CHECK

Fluid level should be checked with the fluid warmed up to 50 to 80°C (122 to 176°F).

Scheme 39

Scheme 39: FLUID LEVEL CHECK
Scheme 39: FLUID LEVEL CHECK

Scheme 40

Scheme 40
Scheme 40

Scheme 41

Scheme 41
Scheme 41

Scheme 42

Scheme 42
Scheme 42
  1. Check for fluid leakage.
  2. With the engine warmed up, drive the vehicle to warm up the CVT fluid. When ambient temperature is 20°C (68°F), it takes about 10 minutes for the CVT fluid to warm up to 50 to 80°C (122 to 176°F).
  3. Park the vehicle on a level surface and set the parking brake.
  4. With engine at idle, while depressing brake pedal, move the selector lever throughout the entire shift range and return it to the "P" position. (Scheme 39): Checking Fluid Leakage
  5. Press the tab on the CVT fluid level gauge to release the lock and pull out the CVT fluid level gauge from the CVT fluid charging pipe. (Scheme 40): Identifying Tab On CVT Fluid Level Gauge To Release Lock
  6. Wipe fluid off the CVT fluid level gauge. Then rotate the CVT fluid level gauge 180° and re-insert it into the CVT charging pipe as far as it will go. CAUTION: Always use lint free paper towels to wipe fluid off the CVT fluid level gauge. (Scheme 41): Identifying CVT Fluid Level Gauge And CVT Fluid Charging Pipe
  7. Remove the CVT fluid level gauge and check that the fluid level is within the specified range as shown. If the fluid level is at or below the low side of the range, add the necessary specified NISSAN CVT fluid through the CVT charging pipe. Fluid grade: Refer to " «MR20DE»(ref-273042-S33967798442007113000000) ". CAUTION: Only use specified NISSAN CVT fluid. Do not overfill the CVT. (Scheme 42): Identifying CVT Fluid Level Gauge
  8. Install the CVT fluid level gauge to the CVT fluid charging pipe until it locks. CAUTION: When CVT fluid level gauge is installed into the CVT fluid charging pipe, make sure that the CVT fluid level gauge is securely locked in place.

FLUID CONDITION CHECK

Fluid statusConceivable causeRequired operation
Varnished (viscous varnish state)CVT fluid become degraded due to high temperatures.Replace the CVT fluid and check the CVT main unit and the vehicle for malfunctions (wire harness, cooler pipes, etc.)
Milky white or cloudyWater in the fluidReplace the CVT fluid and check for places where water is getting in.
Large amount of metal powder mixed in fluidUnusual wear of sliding parts within CVTReplace the CVT fluid and check for improper operation of the CVT.

FLUID CONDITION REFERENCE

Checking Fluid. Scheme 43

Scheme 43: Checking Fluid
Scheme 43: Checking Fluid

Changing CVT Fluid

  1. Remove drain plug, and drain CVT fluid from oil pan.
  2. Install drain plug with new gasket to oil pan and tighten to the specified torque. Drain plug: Refer to " «COMPONENTS»(ref-273051-S29635456202007113000000) ". CAUTION: Do not reuse drain plug gasket.
  3. Fill CVT fluid from CVT fluid charging pipe to the specified level. Fluid grade and capacity: Refer to " «MR20DE»(ref-273042-S33967798442007113000000) ". CAUTION: Use only Genuine NISSAN CVT Fluid NS-2. Do not mix with other fluid. Using CVT fluid other than Genuine NISSAN CVT Fluid NS-2 will deteriorate in driveability and CVT durability, and may damage the CVT, which is not covered by the warranty. When filling CVT fluid, take care not to scatter fluid on heat generating parts such as exhaust. Sufficiently shake the container of CVT fluid before using.
  4. With the engine warmed up, drive the vehicle in an urban area. When ambient temperature is 20°C (68°F), it takes about 10 minutes for the CVT fluid to warm up to 50 to 80°C (122 to 176°F).
  5. Check CVT fluid level and condition. Refer to " «CHECKING CVT FLUID»(ref-273051-S08492064662007113000000) ".
  6. Repeat steps 1 through 5 if CVT fluid is contaminated. CAUTION: Delete CVT fluid deterioration date with CONSULT-III after changing CVT fluid.

Cross-Sectional View - CVT SYSTEM. Scheme 44

Scheme 44: Cross-Sectional View - CVT SYSTEM
Scheme 44: Cross-Sectional View - CVT SYSTEM

CVT Control System Diagram. Scheme 45

Scheme 45: CVT Control System Diagram
Scheme 45: CVT Control System Diagram

Hydraulic Control System Diagram. Scheme 46

Scheme 46: Hydraulic Control System Diagram
Scheme 46: Hydraulic Control System Diagram

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 4500 rpm.

Transmission Fluid Pressure Sensor A (Secondary Pressure Sensor)

  1. 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.
  2. 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.

Fluid Leakage and Fluid Level Check

  1. Inspect for fluid leakage and check the fluid level. Refer to " «CHECKING CVT FLUID»(ref-273051-S08492064662007113000000) ".

Inspect the fluid condition.

Fluid statusConceivable causeRequired operation
Varnished (viscous varnish state)Clutch, brake scorchedReplace the CVT fluid and check the CVT main unit and the vehicle for malfunctions (wire harnesses, cooler pipes, etc.)
Milky white or cloudyWater in the fluidReplace the CVT fluid and check for places where water is getting in.
Large amount of metal powder mixed inUnusual wear of sliding parts within CVTReplace the CVT fluid and check for improper operation of the CVT.

FLUID CONDITION REFERENCE

Checking A/T Fluid. Scheme 47

Scheme 47: Checking A/T Fluid
Scheme 47: Checking A/T Fluid

Scheme 48

Scheme 48: Stall Test Procedure
Scheme 48: Stall Test Procedure

Scheme 49

Scheme 49
Scheme 49

Scheme 50

Scheme 50
Scheme 50

Scheme 51

Scheme 51
Scheme 51

Scheme 52

Scheme 52
Scheme 52
  1. Inspect the amount of engine oil. Replenish the engine oil if necessary.
  2. Drive for about 10 minutes to warm up the vehicle so that the CVT fluid temperature is 50 to 80°C (122 to 176°F). Inspect the amount of CVT fluid. Replenish if necessary. (Scheme 48): Checking A/T Fluid Temperature
  3. Securely engage the parking brake so that the tires do not turn.
  4. Install a tachometer where it can be seen by driver during test. It is good practice to mark the point of specified engine rpm on indicator. (Scheme 49): Engaging Parking Brake
  5. Start engine, apply foot brake, and place selector lever in "D" position. (Scheme 50): Identifying Selector Lever In "D" Position
  6. While holding down the foot brake, gradually press down the accelerator pedal.
  7. Quickly read off the stall speed, and then quickly remove your foot from the accelerator pedal. CAUTION: Do not hold down the accelerator pedal for more than 5 seconds during this test. Stall speed: 2,500 - 3,000 rpm (with MR20DE) Stall speed: 2,050 - 3,550 rpm (with QR25DE) (Scheme 51): Identifying Accelerator Pedal Position
  8. Move the selector lever to the "N" position.
  9. Cool down the CVT fluid. CAUTION: Run the engine at idle for at least 1 minute.
  10. Repeat steps 6 through 9 with selector lever in "R" position. (Scheme 52): Moving Selector Lever To "N" Position

Check CVT Fluid Deterioration Date

"CVTF DETERIORATION DATE"

More than 210000

It is necessary to change CVT fluid.

Less than 210000

It is not necessary to change CVT fluid.

CAUTIONTouch "CLEAR" after changing CVT fluid, and then erase "CVTF DETERIORATION DATE".
  1. Turn ignition switch OFF.
  2. Disconnect CVT unit harness connector.
  3. Check resistance between CVT unit harness connector terminals. RESISTANCE SPECIFICATION CHART Name Connector Terminal Temperature °C (°F) Resistance (Approx.) CVT fluid temperature sensor F46 17 - 19 20 (68) 6.5 kohms 80 (176) 0.9 kohms
  4. If NG, replace the transaxle assembly. Refer to " «REMOVAL AND INSTALLATION (MR20DE)»(ref-273051-S13725889932007113000000) ". see scheme 62: Checking Resistance Between CVT Unit Harness Connector Terminals
NameConditionCONSULT-III "DATA MONITOR" (Approx.)Resistance (Approx.)
ATF TEMP SEN20°C (68°F)2.0 V6.5 kohms
80°C (176°F)1.0 V0.9 kohms

CVT FLUID TEMPERATURE SENSOR SPECIFICATION CHART

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