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 up-shift, does not down-shift or the shift point is too high or too low, conduct the following road test referring to the automatic shift schedule and simulate the problem symptoms.

ROAD TEST

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

1. D POSITION TEST (NORM AND PWR PATTERN)
Shift into the D position and fully depress accelerator pedal then check the following points:
(a) Check up-shift operation
Check that 1 -> 2, 2 -> 3 and 3 -> O/D up-shift takes place, at the shift point shown in the automatic shift schedule.
Conduct the test for both Normal and Power patterns.

HINT:
O/D Gear Up-shift and Lock-up Prohibition Control
(1) When the following 2 conditions occur at the same time, the ECM prohibits O/D gear up-shift and lock-up.
- The engine coolant temperature is 60°C (140°F) or less.
- The vehicle speed is 63 km/h (39 mph) or less.
However, if the engine coolant temperature is below 60°C (140°F) but the vehicle speed exceeds 63 km/h (39 mph), O/D gear and lock-up prohibition is canceled.
Cancellation continues until the IG SW is turned OFF.
(2) If there is a 10 km/h (6 mph) difference between the set cruise control speed and vehicle speed.
3rd Gear Up-shift Prohibition Control
When the following 2 conditions occur at the same time, the ECM prohibits up-shift to 3rd gear.
- The engine coolant temperature is 35°C (95°F) or less.
- The vehicle speed is 40 km/h (25 mph) or less.
However, if the engine coolant temperature is below 35°C (95°F) but the vehicle speed exceeds 40 km/h (25 mph), 3rd gear prohibition is canceled.
Cancellation continues until the 16 SW is turned OFF.

(b) Check for shift shock and slip.
Check for shock and slip at the 1 -> 2, 2 -> 3 and 3 -> O/D up-shifts.
(c) Check for abnormal noises and vibration.
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 abnormal noises and vibration must be performed very thoroughly as it could also be due to loss of balance in the propeller shaft, differential, torque converter clutch, etc.

(d) Check kick-down operation.
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.
(e) Check abnormal shock and slip at kick-down.
(f) Check the lock-up mechanism.
(1) Drive in the D position, O/D gear, at a steady speed (lock-up ON) of about 58 km/h (36 mph).
(2) Lightly depress the accelerator pedal and check that the RPM does not change abruptly. If there is a big jump in RPM, there is no lock-up.

2. 2 POSITION TEST
Shift into the 2 position and fully depress the accelerator pedal and check the following points:
(a) Check up-shift operation
Check to see that the 1 -> 2 up-shift takes place and that the shift point conforms to the automatic shift schedule.

HINT: There is no O/D up-shift and lock-up in the 2 position.

(b) Check engine braking
While running in the 2 position and 2nd gear, release the accelerator pedal and check the engine braking effect.
(c) Check for abnormal noises during acceleration and deceleration and for shock at up-shift and down - shift.

3. L POSITION TEST
Shift into the L position and fully depress the accelerator pedal and check the following points:
(a) Check no up-shift
While running in the L position, check that there is no up-shift to 2nd gear.
(b) Check engine braking
While running in the L position, release the accelerator pedal and check the engine braking effect.
(c) Check for abnormal noises during acceleration and deceleration.

4. 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 personnel and obstructions.

5. P POSITION TEST
Stop the vehicle on a gradient (more than 50) and after shifting into the P position, release the parking brake.
Then check that the parking lock pawl holds the vehicle in place.