Circuit Description

WARNING: This page is about a different car, the 2002 GMC Yukon XL, 2002 GMC Sierra, 2002 Chevrolet Suburban, and 2002 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The flow of transmission fluid starts in the transmission pan. It is then drawn through the filter and transmission case into the oil pump assembly. The oil pump assembly pressurizes the fluid, which becomes the main supply line of fluid. This fluid is directed to various components and hydraulic circuits within the transmission. The pressure regulator valve receives this fluid and directs it to the converter clutch shift valve. The converter clutch shift valve directs hot fluid leaving the torque converter, or regulated converter feed fluid, through the cooler line to the transmission oil cooler. The transmission oil cooler is located in the radiator. The vehicle may also be equipped with an auxiliary oil cooler. The cooled fluid is returned to the transmission through the return cooler line and into center lube port of the transmission. The Transmission Fluid Temperature (TFT) sensor, senses the fluid temperature in the transmission pan.

If the PCM detects a high transmission fluid temperature for a long period of time, then DTC P0218 sets. DTC P0218 is a type "C" DTC.