Code 21, Code 22, Code 23, Code 24: Wheel Speed Equals Zero Mph: Notes
Each wheel speed sensor generates a signal which is proportional to wheel speed. If any wheel speed signal is less than 50 percent of other wheel speeds when vehicle is moving, ABS module disables Anti-Lock Brake System (ABS) and illuminates ABS light. See Fig 1 .
Code will set if one wheel speed signal is less than 50 percent of other wheel speeds. This code may set any time vehicle is moving faster than 5 MPH and is not in ABS braking. This code may be set together with Code 25/26/27/28. Failure may first appear to be an intermittent short or open which sets Code 25/26/27/28. Subsequent complete failure may then set code. Drive vehicle faster than 40 MPH to check for reappearance of failure.