Road Test

U760E 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 attempt to duplicate the problem symptoms.

2. ROAD TEST

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

(a) D position test:

Move the shift lever to D and fully depress the accelerator pedal. Check the following:

(1) Check up-shift operation.

Check that the 1 to 2, 2 to 3, 3 to 4, 4 to 5 and 5 to 6 up-shifts take place, and that the shift points conform to the automatic shift schedule.

HINT
6th Gear Up-shift Prohibition Control

* Engine coolant temperature is 48°C (118°F) or less and vehicle speed is 51 km/h (32 mph) or less.
* ATF temperature is 0°C (32°F) or less.
5th Gear Up-shift Prohibition Control

* Engine coolant temperature is 48°C (118°F) or less and vehicle speed is 51 km/h (32 mph) or less.
* ATF temperature is 0°C (32°F) or less.
4th Gear Up-shift Prohibition Control

* Engine coolant temperature is 48°C (118°F) or less and vehicle speed is 40 km/h (25 mph) or less.
Lock-up Prohibition Control

* Brake pedal is depressed.
* Accelerator pedal is released.
* Engine coolant temperature is 60°C (140°F) or less.
(2) Check for shift shock and slippage.

Check for shock and slippage at the 1 to 2, 2 to 3, 3 to 4, 4 to 5 and 5 to 6 up-shifts.

(3) Check for abnormal noise and vibration.

Check for abnormal noise and vibration when up-shifting from 1 to 2, 2 to 3, 3 to 4, 4 to 5 and 5 to 6 while driving with the shift lever in D, and also 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 2 to 1, 3 to 2, 4 to 3, 5 to 4, and 6 to 5 kick-downs 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.

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

(6) Check the lock-up mechanism.

* Drive the vehicle with the shift lever in D (4th, 5th or 6th gear) at a steady speed (lock-up ON).

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

HINT
* There is no lock-up function in 1st, 2nd and 3rd gears.
* If there is a jump in engine speed, this indicates that lock-up is not operating.
(b) S position test

Move the shift lever to S and check the following:

(1) Check shift operation.

* With the shift lever in S (while the vehicle is stopped), repeatedly move the shift lever toward "+" and check that the shift position on the combination meter changes as follows: 1 to 2, 2 to 3, 3 to 4, 4 to 5 and 5 to 6.

* While driving in 5th gear with the S5 range selected (at a vehicle speed of approximately 55 to 65 km/h (34 to 40 mph), move the shift lever toward "-" and check if the down-shift to 4th gear and proper engine braking occurs.

* While driving in 4th gear with the S4 range selected (at a vehicle speed of approximately 35 to 45 km/h (22 to 28 mph), move the shift lever toward "-" and check if the down-shift to 3rd gear and proper engine braking occurs.

* While driving in 3rd gear with the S3 range selected (at a vehicle speed of approximately 20 to 30 km/h (12 to 19 mph), move the shift lever toward "-" and check if the down-shift to 2nd gear and proper engine braking occurs.

* While driving in 2nd gear with the S2 range selected (at a vehicle speed of approximately 15 to 25 km/h (9 to 16 mph), move the shift lever toward "-" and check if the down-shift to 1st gear and proper engine braking occurs.

HINT
Changing ranges (with the shift lever in S position) is prohibited under either of the following conditions:

* If down-shifting may cause excessive engine speed.
* If the driver continuously down-shifts. (Down-shifting to 1st may not be performed.)
(c) R position test:

Move the shift lever to R and lightly depress the accelerator pedal. 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.

(d) P position test:

Stop the vehicle on an incline (more than 5°). Then move the shift lever to P and release the parking brake. Check that the parking lock pawl holds the vehicle in place.