Code 37 - Erratic Vehicle Speed Sensor Signal: Notes

Code 37 is caused by an erratic Vehicle Speed Sensor (VSS) signal. Code is set if VCM detects 3 intermittent VSS signals while vehicle speed is greater than 12 MPH (brake released) or 20 MPH (brake applied) during one ignition cycle.

Fig 1: Wheel/Vehicle Speed Sensors Schematics (4.3L M/T - VIN Z)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Wheel/Vehicle Speed Sensors Schematics (Except 4.3L M/T - VIN Z)

Courtesy of GENERAL MOTORS CORP.

Fig 3: Code 37 - Erratic VSS Signal - Flow Chart

Courtesy of GENERAL MOTORS CORP.