Control System/Component Testing

The cause of problems in the F3A21 is deterioration of the oil pressure control system and defective adjustment.
In order to carry out diagnosis of these systems effectively, carry out troubleshooting by the following procedure.





1. Gain a full understanding of the conditions under which the trouble symptoms that the user is complaining about occur, including frequency of occurrence.
2. Carry out adjustment of the basic inspection items (ATF, throttle cable, Park/Neutral position switch, manual control cable).
3. Carry out a road test and check the trouble symptoms.
4. Determine the probable cause from the Troubleshooting Chart.
Carry out the inspection of the hydraulic pressure control system and the main body in that order.
5. If the probable cause is in the hydraulic pressure control system, carry out a hydraulic pressure test.
If the result is normal, check for the probable cause in one of the other systems.
If there is an abnormality in the oil pressure test, carry out inspection and adjustment according to the hydraulic pressure troubleshooting chart.
6. If the probable cause is in the A/T main body system, determine which part is malfunctioning by means of a stall test, and then carry out an overhaul.
7. After repairs are completed, carry out a road test to check that the malfunction has been repaired.


ROAD TEST
1. Before carrying out a road test, carry out the following inspections.
- Fluid level and condition of fluid
- Adjustment of throttle control cable
- Condition of selector lever, Park/Neutral position switch and linkages
2. Drive until the fluid temperature reaches the normal temperature [70-80°C (158-176°F)].
3. Compare the vehicle speed when shifting for the shift patterns in the next section with the actual vehicle speed, and carry out the subsequent test.





4. If the inspection shows an abnormality, determine the cause according to the Troubleshooting Chart.




SHIFT PATTERN





TROUBLESHOOTING CHART

PROBABLE CAUSE
1. Engine starting system
2. Insufficient engine output
3. Poor oil pump discharge pressure
4. Clogged oil filter
5. Torque converter
- Malfunction of stator one-way clutch
- Burned out stator one-way clutch
6. One-way clutch
- Malfunction
- Burn out
7. Front clutch
- Sticking of piston
- Foreign material caught in check valve
- Damaged seal ring
- Worn disc
- Deformed return spring
- Excessive clutch clearance
8. Rear clutch
- Sticking of piston
- Foreign material caught in check valve
- Damaged seal ring
- Worn disc
- Deformed return spring
- Excessive clutch clearance
9. Low-reverse brake
- Sticking of piston
- Damaged seal ring
- Worn disc
- Deformed return spring
- Excessive clutch clearance
10. Kickdown brake
- Sticking of piston
- Damaged seal ring
- Kickdown servo poorly adjusted
- Malfunction of anchor rod
- Burned out kickdown band
- Worn kickdown band
- Deformed return spring
- Kickdown servo bore worn
- Kickdown servo bore check valve malfunction
11. Valve body
- Improper installation
- Damaged O-ring at installation surfaces
- Sticking of check ball
12. Malfunction of throttle valve
13. Governor
- Damaged weight
- Clogged filter
14. Regulator valve
- Improper adjustment
- Malfunction
15. Line pressure relief valve
- Sticking of ball
- Deformed or damaged spring
16. Low-relief valve
- Sticking of ball
- Deformed or damaged spring
17. Malfunction of 1-2 shift valve
18. Malfunction of 2-3 shift valve
19. Malfunction of 2-3 control valve
20. Malfunction of range control valve
21. Malfunction of torque converter control valve
22. Malfunction of kickdown valve
23. Malfunction of N-D accumulator valve
24. Malfunction of 1-2 accumulator valve
25. Malfunction of 1-2 engine brake valve
26. Parking mechanism failure