TORQUE CONVERTER STALL TEST
This test measures the maximum engine speed when the selector lever is in the D or R position. The torque converter stalls to test the operation of the torque converter, starter motor, one-way clutch operation, the holding performance of the clutches, and brakes in the transmission.
| CAUTION | Do not let anybody stand in front of or behind the vehicle while this test is being carried out. |
- Check the automatic transmission fluid level and temperature, and the engine coolant temperature. Fluid level : At the HOT mark on the oil level gauge Fluid temperature : 80-100°C Engine coolant temperature : 80-100°C
- Chock both rear wheels (left and right).
- Apply the parking brake lever with the brake pedal fully depressed.
- Start the engine.
- Move the selector lever to the D position, fully depress the accelerator pedal and take a reading of the maximum engine speed at this time.
| CAUTION | The throttle should not be left fully open for more than eight seconds. If carrying out the stall test two or more times, move the selector lever to the N position and run the engine at 1,000 RPM to let the automatic transmission fluid cool down before carrying out subsequent tests. Standard value stall speed : 2,100-2,900 RPM Move the selector lever to the R position and carry out the same test again. Standard value stall speed : 2,100-2,900 RPM |
Scheme 8
- Stall speed is too high in both D and R ranges Low line pressure Low & reverse brake slippage
- Stall speed is too high in D range only Underdrive clutch slippage
- Stall speed is too high in R range only Reverse clutch slippage
- Stall speed too low in both D and R ranges Malfunction of torque converter Insufficient engine output (Scheme 8): Identifying Reverse Clutch, Low-Reverse Brake, Underdrive Clutch & Torque Converter
Scheme 9
Scheme 10
Scheme 11
- Warm up the engine until the automatic transmission fluid temperature is 80-100°C.
- Jack up the vehicle so that the wheels are free to turn.
- Connect the special tool (oil pressure gauge) to each pressure discharge port.
- Measure the hydraulic pressure at each port under the conditions given in the standard hydraulic pressure table, and check that the measured values are within the standard value ranges.
- If a value is outside the standard range, correct the problem while referring to the hydraulic pressure test diagnosis table. (Scheme 9): Identifying Low & Reverse Brake Pressure Port, Under Drive Clutch Pressure Port & Second Brake Pressure Port (Scheme 10): Identifying Damper Clutch Apply Pressure Port & Damper Clutch Release Pressure Port (Scheme 11): Identifying Reverse Clutch Pressure Port & Overdrive Clutch Pressure Port
Hydraulic Pressure Test Table. Scheme 12
Hydraulic Pressure Test Diagnosis Table (1 Of 2). Scheme 13
Hydraulic Pressure Test Diagnosis Table (2 Of 2). Scheme 14
See also:
• THROTTLE POSITION (TP) SENSOR