Sensors and Transmission Diagnostics

Most modern vehicles are equipped with a number of computer modules and sensors in the engine and transmission to ensure good performance and drivability, control emissions, and safety. So, what is involved in transmission diagnistics?

The Onboard Diagnostic (OBD) system can detect most issues and is what will trigger your “check engine” light to come on.  The check engine light can indicate numerous issues, but you have to connect to the OBD to get the codes for the exact issue(s).

The Powertrain Control Module (PCM) controls the engine and transmission, though some vehicles have a separate Transmission Control Module (TCM).  Many of these sensors can indicate an issue with the transmission or other parts of the engine, and can affect the performance and life of your transmission.

  • Vehicle speed sensor
  • Transmission Input & Output Speed Sensors
  • Turbine Speed Shaft Sensor
  • Manifold airflow sensor
  • Manifold absolute pressure sensor
  • Coolant Temperature sensor
  • Throttle position sensor
  • Differential speed sensor
  • Overdrive switch
  • Brake switch
  • Transmission Range sensor or manual lever position switch
  • Transmission Fluid Temperature Sensor
diagnosis tool transmissions

Sensors do not have a factory recommended replacement time table.  They either last for the life of the vehicle, or fail and will need to be replaced.  Make sure you take your vehicle to a trusted mechanic if you have a check engine light, or if you notice any unusual or concerning noises or driving issues. These are vital when it comes to transmission diagnostics.