Diagnostic Aids

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

Fig 1: DTC 24 & 72 Schematic - 1994 Diesel

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC 24 & 72 Schematic - 1994 Gasoline

Courtesy of GENERAL MOTORS CORP.

Fig 3: DTC 24 & 72 Flow Chart - 1994

Courtesy of GENERAL MOTORS CORP.