P0642 OBD II Trouble Code Sensor Reference Voltage A Circuit Low

Symptoms of P0642 OBD II Trouble Code

  • Failure of the transmission to shift between sport and economy modes
  • Transmission shifting malfunctions
  • Delayed (or no) transmission engagement
  • Failure of the transmission to switch between all-wheel and two-wheel drive modes
  • Failure of the transfer case to shift from low to high gear
  • Lack of front differential engagement
  • Lack of front hub engagement
  • Erratic or inoperative speedometer/odometer

Common Causes of P0642 OBD II Trouble Code

  • Bad sensor
  • Defective or blown fuses and/or fusible links
  • Faulty system power relay
  • Open circuits and/or connectors

Severity of P0642 OBD II Trouble Code

The severity of a stored P0642 depends upon which sensor circuit is experiencing a low voltage condition. Other stored codes must be considered before a determination of severity can be made.