Crawler mode sometime just gets rid of the brake function . Not actually slowing down the car .
Normal mode would be Fwd / Brake / Reverse ( you have to brake before reversing )
Crawler mode would Fwd / Reverse ( you can go from forward staight into reverse )
Race mode would be Fwd and Brake ( no reverse )
Check and see if you can go from forward to reverse without braking . Dont do it flat out as it can brake stuff .