Code 72, Vehicle Speed Sensor Loss - 3.4L "F" Body, 4.3L & 5.7L "B", "D" & "F" Bodies: Notes

Fig 1: Code 72 - VSS Circuit Schematic (3.4L "F" Body)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 72 - VSS Circuit Schematic (4.3L & 5.7L "B" Body)

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Fig 3: Code 72 - VSS Circuit Schematic (5.7L "D" Body)

Courtesy of GENERAL MOTORS CORP.

Fig 4: Code 72 - VSS Circuit Schematic (5.7L "F" Body)

Courtesy of GENERAL MOTORS CORP.

Speed sensor is a PM generator located on transmission output shaft.

1. Disable Traction Control (TC) system (if equipped) when performing this step. Whenever ignition is cycled off and then back on, TC system will default on.
2. An intermittent connection at VSS or PCM may cause code to set. Inspect harness and all related connections. Check for damage or pushed out terminals.
3. Ensure harness is not routed too close to hot exhaust components.