What transmission temperature sensor adapter options are available for a 2014–2019 Duramax Silverado/Sierra?Updated 4 hours ago

For the 2014–2019 Duramax equipped with the Allison transmission, there are two main installation options for a transmission temperature sensor:

• Diagnostic (Test) Port Adapter

  • Connects to the factory “Diagnostic Pressure Port” on the Allison transmission

  • Located on the transmission case near the external spin-on filter

  • Originally designed for checking internal line pressure

  • Provides a reading of internal transmission fluid temperature

• Transmission Cooler Line T-Fitting Adapter

  • Installs into the ⅝” transmission cooler line

  • Reads fluid temperature as it exits the transmission and flows to the cooler

  • Measures slightly cooler temperatures compared to internal transmission readings

• Temperature Difference Note

  • Diagnostic port readings are typically higher than cooler line readings

  • Testing has shown differences of up to approximately 35°F depending on conditions and vehicle setup