Road Test

PROBLEM SYMPTOM CONFIRMATION/ROAD TEST PROCEDURE

Taking into consideration the results of the customer problem analysis, try to reproduce the symptoms of the trouble. If the problem is that the transaxle does not up-shift, does not down -shift, or the shift point is too high or too low, conduct the following road test the and simulate the problem symptoms.

NOTICE: Do this test at normal ATF temperature 50-80°C (122-176°F).

1. D POSITION TEST
Shift into the D position.
Switch O/D on.
Keep the accelerator pedal fully depressed and check the following points.
(a) Check to see that the 1 -> 2, 2 -> 3 and 3 -> O/D up-shifts take place, and shift points should conform to those in the automatic shift schedule.

HINT: There is no O/D up-shift or lock-up when the coolant temperature is below 70°C (158°F).

EVALUATION
(1) If there is no 1 -> 2 up-shift:
- Shift solenoid valve No.2 is stuck
- 1 -> 2 shift valve is stuck
(2) If there is no 2 -> 3 up-shift:
- Shift solenoid valve No.1 is stuck
- 2 -> 3 shift valve is stuck.
(3) If there is no 3 -> O/D up shift:
- 3 -> 4 shift valve is stuck
(4) If the shift point is defective:
- Throttle valve. 1 -> 2 shift valve, 2 -> 3 shift valve, 3 -> 4 shift valve etc., are defective
(5) If the lock-up is defective:
- Shift solenoid valve SL is stuck
- Lock-up relay valve is stuck

(b) If the same way, check the shock and slip at 1 -> 2, 2 -> 3 and 3 -> O/D up shifts.

EVALUATION
If the shock is excessive:
- Line pressure is too high
- Accumulator is defective
- Check ball is defective

(c) Run at the D position lock-up or O/D gear and check for abnormal noises and vibration.

HINT: The check for the cause of the abnormal noises and vibration must be made with extreme care as it could also be due to lose of balance in the propeller shaft, differential, torque converter clutch, etc.

(d) While running in the D position, 2nd. 3rd and O/D gears. check to see that the possible kick-down vehicle speed limits for 2 -> 1, 3 -> 2 and O/D -> 3 kick-downs conform to those indicated on the automatic shift schedule.
Check for abnormal shock and slip at kick-down. Check for the lock-up mechanism.
(1) Drive in the D position, O/D gear. at a steady speed (lock-up ON).
(2) Lightly depress the accelerator pedal and check that there is lock-up. If there is a big jump in engine RPM, there is no lock-up.

2. 2 POSITION TEST
Shift into the 2 position.
Keep the accelerator pedal fully depressed and check the following points.
(a) Check to see that the 1 -> 2 up-shift takes place and that the shift point conforms to that shown on the automatic shift schedule.
(b) There is no 3rd up-shift and lock-up in the 2 position.
(c) While running in the 2nd gear of 2 position, release the accelerator pedal and check the engine braking effect.

EVALUATION
If there is no engine braking effect:
- No.1 brake defective
(d) Check for abnormal noises during acceleration and deceleration, and for shock during up-shift and down-shift.

3. L POSITION TEST
(a) While running in the L position, check to see that there is no up-shift to 2nd gear.
(b) While running in the L position, release the accelerator pedal and check the engine braking effect.

EVALUATION
If there is no engine braking effect:
- 1st and reverse brake is defective
(c) Check for abnormal noises during acceleration and deceleration.

4. R POSITION TEST
Shift into the R position and, while starting at full throttle, check for slipping.

CAUTION: Before conducting this test ensure that the test area is free from personnel and obstruction.

5. P POSITION TEST
Stop the vehicle on a gradient (more than 5°) and after shifting into the P position, release the parking brake.
Then check that the parking lock pawl holds the vehicle in place.