HYDRAULIC PRESSURE TEST


caution This test must be performed with the CVT fluid temperature within the range of 70 to 80°C.
1.Check the engine oil level, and add if necessary.
2.Warm up the engine, and then perform test drive for approx. ten minutes.
3.Check the CVT fluid for leaks, level and contamination. Then top up or change if necessary.
4.Operate the parking brake securely, and then chock the wheels.
5.Connect the M.U.T.-III, and then start the engine.
6.
warning For safety, operators must not stand in front of and at the rear of the vehicle during this test.
caution During this test, leave the brake pedal depressed fully.
Use the M.U.T.-III (data list item No. 20: Secondary pressure) to measure the secondary pressure (line pressure) by observing the conditions listed in the hydraulic pressure table.
7.Stop the engine.
8.If not within the standard value, take necessary steps according to the hydraulic pressure test diagnosis table.

Hydraulic pressure table (reference value)
Selector lever position
 During engine idling
 During engine stall
P, N
 0.50 MPa
 -
R, D (Ds, B, L)
 0.50 - 1.18 MPa
 4.04 - 4.54 MPa
Judgement result
 Probable cause
 Remedy
During engine idling
 Low at all ranges [P, R, N, D (Ds, B, L)]
 The hydraulic pressure delivery system or the oil pump may be defective.
  • Worn oil pump

 Replace the CVT assembly

  • Damaged oil pump chain and sprocket

  • Defective pressure regulator valve, or deteriorated spring

  • Leaks in the hydraulic pressure circuit ranging from the oil strainer via the oil pump to the pressure regulator valve

  • The engine idling speed is low.

 Check the engine system, and repair or replace if necessary.
Low at certain range(s) only.
 Oil leaks may be present in the device or circuit relating to that range.
 Replace the CVT assembly
High
 Sensor(s) or the pressure adjusting function may be defective.
  • Malfunction of the accelerator pedal position sensor

 Check the accelerator pedal position sensor, and repair or replace if necessary.

  • Malfunction of the oil pressure sensor

 Replace the CVT assembly

  • Malfunction of the line pressure solenoid valve (stuck OFF, open circuit or short circuit)

  • Malfunction of the pressure regulator valve
During engine stall
 Oil pressure does not rise from that during the engine idling.
 Sensor(s) or the pressure adjusting function may be defective.
  • Malfunction of CVT-ECU

 Check the CVT-ECU, and repair or replace if necessary.

  • Malfunction of the line pressure solenoid valve (stuck ON or short circuit)

 Replace the CVT assembly

  • Malfunction of the pressure regulator valve
Oil pressure rises, but is not within the standard value.
 The pressure supply system, sensor(s) or the pressure adjusting function may be defective.
  • Worn oil pump

  • Malfunction of the line pressure solenoid valve

  • Malfunction of the pressure regulator valve
Low at certain range(s) only.
 Oil leaks may be present in the device or circuit relating to that range.