Built-In Test Equipment (BITE) Test Cycle
WARNING: This page is about a different car, the 1993 Mercedes-Benz 300D. However, it is still accessible from the selected car via links, so may be relevant.
Test cycle begins when wheel speed in all 3 speed channels exceeds 3 MPH. Test cycle, activated by speed sensor voltage, also monitors safety circuit and logic section. Electronic control unit is given test signals to check whether or not correct output signals are available.