Road Test

U341E AUTOMATIC TRANSAXLE: AUTOMATIC TRANSAXLE SYSTEM: ROAD TEST

1. PROBLEM SYMPTOM CONFIRMATION

(a) Based on the result of the customer problem analysis, try to reproduce the symptoms. If the problem is that the transaxle does not shift up or down, 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.

2. ROAD TEST

NOTICE:
Perform the test at the ATF (Automatic Transmission Fluid) temperature 50 to 80°C (122 to 176°F) in the normal operation.

(a) D position test:

Shift into the D position and check the following points.

(1) Check up-shift operation.

Check that 1 -> 2, 2 -> 3 and 3 -> 4 up-shifts take place, and that the shift points conform to the automatic shift schedule Pressure, Vacuum and Temperature Specifications.

HINT
4th Gear Up-shift Prohibition Control

* Engine coolant temperature is 40°C (104°F) or less.
* ATF temperature is 0°C (32°F) or less.
4th Gear Lock-up Prohibition Control

* Brake pedal is depressed.
* Accelerator pedal is released.
* Engine coolant temperature is 60°C (140°F) or less.
* ATF temperature is 10°C (50°F) or less.

(2) Check for shift shock and slip.

Check for shock and slip at the 1 -> 2, 2 -> 3 and 3 -> 4 up-shifts.

(3) Check for abnormal noise and vibration.

Check for abnormal noise and vibration when up-shifting from 1 -> 2, 2 -> 3 and 3 -> 4 while driving with the shift lever in D, and check while driving in the lock-up condition.

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

(4) Check kick-down operation.

Check vehicle speeds when the kick-down from 2 -> 1, 3 -> 2 and 4 -> 3 take place while driving with the shift lever in D. Confirm that each speed is within the applicable vehicle speed range indicated in the automatic shift schedule Pressure, Vacuum and Temperature Specifications.

(5) Check abnormal shock and slip at kick-down.

(6) Check the lock-up mechanism.

* Drive in the D position (4th gear), at a steady speed (lock-up ON).

* Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.

HINT
If there is a big jump in engine speed, there is no lock-up.

(b) 3 position test:

Shift into the 3 position and check the following points.

(1) Check up-shift operation.

Check that the 1 -> 2 and 2 -> 3 up-shifts take place and that the shift point conforms to the automatic shift schedule Pressure, Vacuum and Temperature Specifications.

HINT
There is no 4th up-shift in the 3 position.

(2) Check engine braking.

While driving in the 3 position and 3rd gear, release the accelerator pedal and check the engine braking effect.

(3) Check for abnormal noise during acceleration and deceleration, and for shock at up-shift and down-shift.

(c) 2 position test:

Shift into the 2 position and check the following points.

(1) Check up-shift operation.

Check that the 1 -> 2 up-shift takes place and that the shift point conforms to the automatic shift schedule Pressure, Vacuum and Temperature Specifications.

HINT
There is no 3rd up-shift and lock-up in the 2 position.

(2) Check engine braking.

While driving in the 2 position and 2nd gear, release the accelerator pedal and check the engine braking effect.

(3) Check for abnormal noise during acceleration and deceleration, and for shock at up-shift and down-shift.

(d) L position test:

Shift into the L position and check the following points.

(1) Check no up-shift.

While driving in the L position, check that there is no up-shift to 2nd gear.

HINT
There is no lock-up in the L position.

(2) Check engine braking.

While driving in the L position, release the accelerator pedal and check the engine braking effect.

(3) Check for abnormal noise during acceleration and deceleration.

(e) R position test:

Shift into the R position, lightly depress the accelerator pedal, and check that the vehicle moves backward without any abnormal noise or vibration.

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

(f) P position test:

Stop the vehicle on a grade (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.