Audi revs but will not drive in reverse...ABS light is on & Brake light flashes on the dash. What do you think I need?
My car has 120000 miles.
My car has an automatic transmission.
The transmission needs around 100 psi pressure to operate all of the forward gears, but it needs 180-190 psi pressure for the reverse gears.
The transmission pump is designed to create 1000 psi of pressure and it is regulated by a pressure regulator located next to the pump. Check the wiring harness to the transmission and check the pressure to the transmission pump through the cooler lines. If the pressure is about 30 psi to 45 psi on the cooler lines and the wiring harness is in good condition, then the pump and the regulator is working correctly. In that case, the problem would now be within the transmission valve body (control module).
If the pressure is higher than 45 psi on the cooler lines, replace the pressure regulator solenoid in the transmission. If you need assistance, get a certified professional, such as one from YourMechanic, to replace the transmission oil pressure switch for your vehicle.