Circuit Description
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The torque converter is the primary source of heat in the transmission. In order to prevent overheating of the torque converter and the automatic transmission fluid, the powertrain control module (PCM) monitors the transmission fluid temperature (TFT), torque converter slip, ambient temperature, and various other conditions. The PCM uses the information it monitors to estimate the torque converter temperature.
If the PCM detects a high TFT, or estimates the temperature of the torque converter to exceed a predetermined temperature, DTC P0218 sets. DTC P0218 is a type C DTC.