Code 38 - Wheel Speed Sensor Error: Notes

Code 38 is caused by an erratic signal from Vehicle Speed Sensor (VSS) or wheel speed sensors. Code is set if VCM detects incorrect signals while vehicle speed is greater than 12 MPH for at least 12 seconds.

Fig 1: Code 38 - Wheel Speed Sensor Error - Flow Chart

Courtesy of GENERAL MOTORS CORP.