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Home >> Saturn >> 1996 >> SW1 Automatic >> Repair and Diagnosis >> Brakes >> Traction Control >> Anti-Lock Brake System >> Diagnostic Trouble Code Charts >> Code 21, Code 22, Code 23 Or Code 24 - Wheel Speed Equals Zero Mph >> Notes
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Code 21, Code 22, Code 23 Or Code 24 - Wheel Speed Equals Zero Mph: Notes

NOTE: To identify circuits and terminals referenced in text and flowcharts, see WIRING DIAGRAM  .

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.

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.

Fig 1: Code 21, 22, 23 Or 24 Diagnostic Flow Chart
G95G15301Courtesy of GENERAL MOTORS CORP.