P0791 OBD II Trouble Code Intermediate Shaft Speed Sensor A Circuit

How to easily diagnose, repair, and what causes a P0791 code which indicates a general malfunction in the A intermediate shaft speed sensor circuit.

Symptoms of P0791 OBD II Trouble Code

  • Hard shifting
  • Numerous instrument panel lights illuminated
  • Poor driveability
  • Erratic engine speed

Common Causes of P0791 OBD II Trouble Code

  • Defective or damaged Intermediate shaft speed sensor
  • Electrical fault in the wires between the speed sensor and modules used
  • Internal ECM and/or TCM issue
  • Other related sensors/solenoids damaged or defective (i.e.: Input shaft speed sensor, Output shaft sensor, Shift solenoid etc.)
  • Dirty or low automatic transmission fluid (ATF)

Severity of P0791 OBD II Trouble Code

I would say this fault is moderately severe. Like mentioned earlier, your automatic transmission may still be functioning OK. That said, it could also be indicative if one or more bigger more pressing issues. Diagnosing any transmission issue ASAP is the best strategy.