Problem Symptom Confirmation (Road Test)

PROBLEM SYMPTOM CONFIRMATION

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

ROAD TEST

NOTICE: Conduct the test at normal operating ATF temperature 50 - 80 °C (122 - 176 °F).

(a) D position test (NORM and PWR pattern)
Shift into the D position and fully depress the accelerator pedal and and check the following points:
(1) Check upshift operation.
Check to see that 1 -> 2, 2 -> 3 and 3 -> 4 upshift takes place, and that the shift points conform to the automatic shift schedule.

HINT:
- 4th Gear Upshift Prohibition Control (1. Coolant temp. is 60 °C (140 °F) or less. 2. If there is a 10 km/h (6mph) difference between the set cruise control speed and vehicle speed.)
- 4th Gear Lock-up Prohibition Control (1. Brake pedal is depressed. 2. Coolant temp. is 60 °C (140 °F) or less.)

(2) Check for shift shock and slip.
Check for shock and slip at the 1 -> 2, 2 -> 3 and 3 -> 4 upshifts.
(3) Check for abnormal noises and vibration.
Run at the D position lock-up or 4th gear and check for abnormal noises and vibration.

HINT: The check for the cause of abnormal noises and vibration must be done very thoroughly as it could also be due to loss of balance in the differential, torque converter clutch, etc.

(4) Check kickdown operation.
While running in the D position, 2nd, 3rd and 4th gears, check to see that the possible kickdown vehicle speed limits for 2 -> 1, 3 -> 2 and 4 -> 3 kick-downs conform to those indicated in the automatic shift schedule.
(5) Check abnormal shock and slip at kickdown.
(6) Check the lock-up mechanism.
- Drive in D position, 4th gear, at a steady speed (lock-up ON) of about 70 km/h (43 mph).
- Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.
If there is a big jump in engine speed, there is no lock-up.
(b) 2 position test
Shift into the 2 position and fully depress the accelerator pedal and check the following points:
(1) Check upshift operation.
Check to see that the 1 -> 2 upshift takes place and that the shift point conforms to the automatic shift schedule.

HINT: There is no 4th upshift and lock-up in the 2 position.

(2) Check engine braking.
While running in the 2 position and 2nd gear, release the accelerator pedal and check the engine braking effect.
(3) Check for abnormal noises during acceleration and deceleration, and for shock at up-shift and down-shift.
(c) L position test
Shift into the L position and fully depress the accelerator pedal and check the following points:
(1) Check no upshift.
While running in the L position, check that there is no upshift to 2nd gear.
(2) Check engine braking.
While running in the L position, release the accelerator pedal and check the engine braking effect.
(3) Check for abnormal noises during acceleration and deceleration.
(d) R position test
Shift into the R position and fully depress the accelerator pedal and check for slipping.

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

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