FixVault

Test Driving the Transmission

Test drive the car as follows:

Before the test drive: 

Test driving: 

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 the Neutral or Park  positions.

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 really engages correctly in each position, and that it does not try to "jump out" of the selected position.

Check the reverse gear: 

Back up the car in the normal way. Check that the reverse light comes on.

Adaptation of Transmission Control Module (TCM) 

Perform Adaptation Of Transmission Control Module (TCM) .

Listen for mechanical noises: 

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

Fault-trace the relevant symptoms in the symptom manager.

Check the function of the transmission while driving 

Economy mode, Sport mode 

During normal driving the gearbox uses the economy mode. The gearbox shifts smoothly. In the event of rapid acceleration, the gearbox switches to the sport mode. Shifting in sport mode is quicker, although still smooth. Check that the gearbox is working correctly.

Start the car with the gear selector in position . Note whether the gears slip or shifting is harsh. Check that the lock-up function engages.

Keep the car stationary on a flat road with the gear selector in N position  . Release the brake and accelerate a little. Does the car move forward?

Start in position D. Drive the car at approximately 70 km/h so that 5th gear engages. Shift the gear selector to positions 4, 3 and L. Check that there is engine braking.

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

Winter (W) 

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

If the function of the transaxle is OK, the fault has been traced and rectified and fault tracing can stopped. If not, select continue to advance with fault tracing.

Fig 1: Identifying Test Driving Transmission
GLL102645Courtesy of VOLVO CARS OF NORTH AMERICA.