K2–74
AUTOMATIC TRANSAXLE
Evaluation of line pressure test
Stall Speed Test
1. Perform mechanical system test preparation. (See K2–72 Mechanical System Test Preparation.)
2. Connect a tachometer.
3. Start the engine.
4. Shift the selector lever to D range.
Caution
• Do not maintain WOT in any gear range for more than 5 seconds or transaxle damage will occur.
• If engine speed recorded by the tachometer exceeds maximum specified rpm, release the
accelerator pedal immediately. Clutch or band slippage is indicator.
5. Firmly depress the brake pedal with the left foot, and gently depress the accelerator pedal to the floor (WOT)
with the right.
6. When the engine speed no longer increases, quickly read the engine speed and release the accelerator pedal.
7. Shift the selector the to N position and let the engine idle for 1 minute or more to cool the ATF.
8. Perform stall tests for the remaining ranges and position in the same manner.
• R position
• Mrange (1GR, 2GR)
Engine stall speed
ATF temperature : 60—70 °C {140—158 °F}
Turn off all electrical loads
2,200—2,600 rpm
9. Turn off the engine.
Evaluation of stall test
Condition Possible cause
Idle
Below specification
Low pressure in all ranges
Worn oil pump
Poor operation of each solenoid
Fluid leaking from oil strainer, oil pump, pressure regulator
valve, torque converter relief valve, and/or pressure relief valve
Pressure regulator valve or pilot valve sticking
Damaged pressure regulator valve spring or pilot valve spring
Low pressure in D and M
range
Fluid leaking from hydraulic circuit of low clutch
Low pressure in R position
only
Fluid leaking from hydraulic circuit of reverse clutch
Fluid leaking from hydraulic circuit of low and reverse brake
clutch
Above specification High pressure in all ranges
Throttle position sensor out of adjustment
TFT sensor malfunction
Poor operation of shift solenoid
Pilot valve sticking
Pressure reducing valve or plug sticking
Stall Below specification Low pressure in all ranges
Throttle position sensor out of adjustment
Pressure control solenoid malfunction
Poor operation of shift solenoid
Pilot valve sticking
Pressure reducing valve or plug sticking
Condition Possible cause
Above specification
In all forward ranges and R
position
Insufficient line pressure
Worm oil pump
Poor operation of low clutch
Poor adjustment or malfunction of TR switch
Oil leaking from oil pump, control valve, and/or transmission
case
Pressure regulator valve or pilot valve sticking
In all forward ranges
Low clutch slippage
Low one-way clutch slippage
Reduction one-way clutch slippage
In R position
Low and reverse brake slippage
Reverse clutch slippage
Reduction brake slippage
Below specification
In all forward ranges and R
position
Engine out of tune
One-way clutch slippage within torque converter
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