Technician A says that some anti-lock braking systems do away with the mechanical proportioning valve Technician B says that the electronic brake control module performs an automatic self-check and warning lamp bulb check on the anti-lock braking system every time the key is turned to the "off'position. Who is correct? Select one: a. Technician A b. Technician B c. Both Technician A and Technician B d. Neither Technician A nor Technician B

c. Both Technician A and Technician B<br /><br />Both Technician A and Technician B are correct. Some anti-lock braking systems (ABS) do away with the mechanical proportioning valve, which is replaced by an electronic control unit that can adjust the brake pressure more precisely. Additionally, the electronic brake control module (EBCM) in ABS systems typically performs an automatic self-check and warning lamp bulb check every time the key is turned to the "off" position.