Flow of Diagnosis

This schedule is intended for guidance when carrying out a road test to check complaints about the operation of automatic transmission AF20/22. Note that speed limits must not be exceeded.

Prior to starting the test drive:

Check the level of the fluid in the transmission before starting the test drive.

Test Driving

1. Check the operation of the starting interlock switch:

Try to start the car with the selector lever in position P or N.
Try to start the car with the selector lever in a position other than P or N.

2. Check the positions of the selector lever:

Make sure that the lever really is in the correct position and does not jump out of the selected position.

3. Check reverse gear:

Reverse the car in the normal manner, checking at the same time that the reversing light comes on.

4. Listen for mechanical noise:
Start in position D. Drive the car so that the transmission is caused to upshift and downshift. Listen for abnormal sounds from the transmission. If you hear anything unusual, cut the test drive short and return to the garage for transmission fault diagnosis. Mechanical faults without a diagnostic trouble code.

5. Check the operation of the transmission while driving:

Sport mode (S)

The transmission should downshift faster. Check gear-shifting speeds

Winter mode (W)

Start, in position D. The transmission should start smoothly in 3rd gear. Check that the kick-down function operates satisfactorily. Check gear-shifting speeds. Check that winter Mode is disengaged at 80 km/h (engine versions without turbo and without On-Board Diagnostic II diagnosis only; turbo versions and versions with On-Board Diagnostic II diagnosis stay in WINTER mode).

Normal position

Start in position D. Check gear-shifting speeds at the smallest possible throttle opening, Also check whether shifting is abrupt or slippage occurs. Check that the lock-up function is present and correct. Lock-up does not work at throttle openings smaller than 4%.

Start in position D. Press the accelerator to the kick-down position (100% throttle opening). After the transmission has shifted from 1st to 2nd gear, press the accelerator to a position just short of the kick-down position (85% throttle opening), Check the gear-shifting speeds for the engine type in question. Also check whether shifting is abrupt or slippage occurs. Check that the lock-up function is present and correct.

DRIVING HINTS

Accelerate slowly. Apply the brakes lightly while accelerating. The lock-up should disengage if engine speed is lower than 2,000 rpm.

Start in position D. Press the accelerator to the kick-down position at different speeds. Check the highest gear-shifting speed at which kick-down downshifting occurs.

Stop the car on a level road with the selector lever in position N. Release the brakes and press the accelerator Slightly. Does the car move forward?

Start in position 3. Drive the car until 3rd gear is engaged. release the accelerator and check that engine braking occurs in 1st gear. Engage position 1 at a higher speed and allow the car to decelerate. Check the gear-shifting points during retardation.

Start in position 1. Accelerate and check whether engine braking is obtainable.

Place the selector lever in position P with the car stationary on a gradient and release the brakes. Does the car move?