Road Test

A343E AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION 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 transmission does not shift up or shift down, or that the shift point is too high or too low, conduct the following road test and reproduce the problem symptoms.

2. ROAD TEST

HINT
The ECM controls the transmission based on the vehicle condition according to the table below.

Automatic Transmission Control





(a) D position test

(1) Check up-shift operation.

Check the 1 -> 2, 2 -> 3 and 3 -> 4 up-shifts.

(2) Check for shift shock and slippage.

Check for shock and slippage 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 also check while driving in lock-up.

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 that the 2 -> 1, 3 -> 2 and 4 -> 3 kick-downs take place when accelerating with the shift lever in D.

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

(6) Check the lock-up mechanism.

Drive in 4th gear with the shift lever in D 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 sudden increase in engine speed, there is no lock-up.

(b) 3 position test

(1) Check up-shift operation.

Check the 1 -> 2 and 2 -> 3 up-shifts.

(2) Check engine braking.

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

(3) Check for abnormal noise.

Check for abnormal noise during acceleration and deceleration, and for shock when up-shifts and down-shifts are performed.

(4) Check the lock-up mechanism.

Drive in 3rd gear with the shift lever in 3 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 sudden increase in engine speed, there is no lock-up.

(c) 2 position test

(1) Check up-shift operation.

Check the 1 -> 2 up-shift.

(2) Check engine braking.

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

(3) Check for abnormal noise.

Check for abnormal noise during acceleration and deceleration, and for shock when up-shifts and down-shifts are performed.

(d) L position test

(1) Check that there is no up-shift.

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

(2) Check engine braking.

While driving with the shift lever in L, release the accelerator pedal and check the engine braking effect.

(3) Check for abnormal noise.

Check for abnormal noise during acceleration and deceleration.

(e) R position test

Move the shift lever to R, lightly depress the accelerator pedal and check that the vehicle moves backward without any abnormal noise or vibration.

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

(f) P position test

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