Diagnostic Aids

Code 24 can set if speedometer is binding. Ensure speedometer cable is free from restrictions and has a secure connection to instrument cluster assembly. Ensure all electrical connections are secure, and all wires are free of opens and shorts.

NOTE: Ensure diagnostic service check has been performed and check speedometer cable operation before continuing diagnosis. After repairs, confirm closed loop operation and no CHECK ENGINE light.

Fig 1: Vehicle Speed Sensor Terminal

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 24 Schematic, Vehicle Speed Sensor Circuit

Courtesy of GENERAL MOTORS CORP.

Fig 3: Code 24 Flow Chart, Vehicle Speed Sensor Circuit

Courtesy of GENERAL MOTORS CORP.