What does P0819 Mean? The Transmission Control Module (TCM) monitors the Up And Down Shift Switch signal. The TCM sets the OBDII code when the Up And Down Shift Switch signal is not to factory specifications. engine code P0819P0819 fixobd P0819dtc P0819obd code P0819obd2 P0819P0819 car codediagnostic code P0819car code P0819check engine code P0819fehlercode P0819P0819 fiatcodigo P0819codigo falla P0819P0819 kody b??dówcodigo de falla P0819 What are the common causes of P0819 ? The Mass Airflow sensor is a hot wire that senses the volume of air entering the intake manifold. The computer uses this information to control fuel mixture. Defective ECU strategies or components will prevent proper regeneration A large air leak at or near the number one oxygen sensor would also cause a lean mixture. How do you troubleshoot P0819 ? The most common repairs for a P0819 are as follows: Replacing the up- and down-shift switch Replacing electrical connectors for the switch Replacing damaged wiring Searches related to P0819 Code - Up And Down Shift Switch To Transmission Range Correlation P0819 P0818