Initial Inspection and Diagnostic Overview

Test drive schedule, description

Note: This schedule is intended to provide guidelines when test driving a car to evaluate complaints about the AW 55-51 automatic transmission.

Caution: Please observe speed limits.

Preparatory work
Check before test driving
Before the test drive:
- check the oil level in the transmission before test driving. See: Oil level, checking
- check that the gear selector cannot be moved with the ignition off
- check that the gear selector cannot be moved with the ignition on and the brake pedal unaffected.

Test driving
Test driving the vehicle
Check the operation of the park / neutral position (PNP) switch:
- it should only be possible to start the engine when the gear selector is in P or N
- try to start the engine with the gear selector in any other position than P or N.

Check the gear selector positions:
- check that the selector engages in each position, and that it does not try to jump out of the selected position.

Check the back-up gear
Back up the vehicle in the normal way.
Check that the back-up light comes on.

Listen for mechanical noises
Start the car with the gear selector in position D. Drive the vehicle so that the transmission shifts up and down. Listen for abnormal noises from the transmission. If you hear noises, stop the test drive and return to the workshop.

Fault-trace the relevant symptoms in the symptom manager.

Checking the function
Check the function of the transmission while driving.

Economy mode, Sport mode
During normal driving the transmission uses the economy mode. The transmission shifts smoothly. In the event of rapid acceleration, the transmission switches to the sport mode. Shifting in sport mode is quicker, although still smooth. Check that the transmission is working correctly. Start the car with the gear selector in position D. Note whether the gears slip or shifting is harsh. Check that the lock-up function engages. Keep the vehicle stationary on a flat road with the gear selector in N position. Release the brake and accelerate a little. Does the vehicle move forward?

Start in position D. Drive the vehicle at approximately 70 km/h so that 5th gear engages. Shift the transmission down in order to gears 4, 3 and 2/L. Check that engine braking occurs.

Stop the vehicle on a slope. Shift the gear selector to position P. Release the brake. Does the vehicle move?

Winter (W)
Start the car with the gear selector in position D. The transmission should start in third gear and give a smooth take-up from standstill. Check that the kickdown function operates.