Theory Of Operation
The purpose of this diagnostic is to check the electrical performance of the on/off shift solenoid A (1) and B (2) circuits. Shift solenoid A (1) engages the Low, Reverse clutch when activated or the Over drive clutch when deactivated. Shift solenoid B (2) engages the 3rd , 5th , Reverse clutch when activated. The electrical failures that are detected include short to battery, short to ground, and open circuit. The power stage driver, which is located in the TCM, detects these electrical malfunctions.