Code 29 - Both Front Wheel Speed Signals Missing: Notes

Code 29 is caused by loss of both left and right front wheel speed sensor signals with vehicle speed greater than 12 MPH (brake released) or 20 MPH (brake applied). Code 29 may be caused by a faulty VCM or 32-way VCM harness connector.

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 29 - Both Front Wheel Speed Signals Missing - Flow Chart

Courtesy of GENERAL MOTORS CORP.