Posted Tue Apr 3, 2018 12:08 PM
Could be the Optical Sensor or it could be bad battery contact with one another or the contact in the battery compartment. Try this...
Turn the Driving Module upside down, take cover off, check batteries are installed properly, put cover back on, with the unit still upside down start Turbo, lift unit up so that you can spin the wheel in either direction real fast with one finger. If the on-screen car moves left and right properly, then your unit is good and you'll have to use some cardboard, velcro tape, etc. to secure the batteries in place better.
If no go, open up unit and give it a good cleaning.
If still no go, then probably the Optical Sensor.