Theory Of Operation
The purpose of this diagnostic is to check the functionality of each of the six variable force solenoid circuits. The six variable force solenoids include a shift solenoid C which controls the 3rd, 5th, Reverse clutch, shift solenoid D which controls the Over Drive clutch, shift solenoid E which controls the Under Drive brake, shift solenoid F which controls the 2nd, 6th brake, pressure control solenoid A which controls the hydraulic line pressure, and torque converter clutch pressure control solenoid which controls the torque converter lock up clutch. The malfunction condition is detected if the measured solenoid feedback current does not correlate to the TCM commanded solenoid current. This failure may be caused by conditions such as internal circuit corrosion or manufacturing defects.