Diagnostic Aids

DTC 24 will set when no vehicle speed is detected at vehicle start off. DTC 72 will set when vehicle speed has been detected and is lost.

Fig 1: DTC 72 Schematic ("G" Series - 4L60-E) Speed Sensor Circuit Loss (Transmission Output Speed Signal)

Fig 2: DTC 72 Schematic ("G" Series - 4L80-E) Speed Sensor Circuit Loss (Transmission Output Speed Signal)

Fig 3: DTC 72 Schematic ("P" Series - 4L80-E) Speed Sensor Circuit Loss (Transmission Output Speed Signal)

Fig 4: DTC 72 Flow Chart (All Models) Speed Sensor Circuit Loss (Transmission Output Speed Signal)