Theory Of Operation

The purpose of the diagnostic is to detect if the Dog Clutch F is stuck in the engaged position while shifting from the extended NEUTRAL position (all clutches should be disengaged) to the DRIVE position. To be able to detect if Dog Clutch F is stuck, the friction Clutch E is engaged after the extended NEUTRAL position has occurred. If the input speed is equal to the output speed multiplied by the gear ratio of the Fourth gear, the Dog Clutch F is stuck in the engaged position

A dog clutch is a type of clutch that couples two rotating shifting elements not by friction but by interference. The two parts of the clutch are designed such that one will push the other, causing both to rotate at the same speed and will never slip. The speeds of the shifting elements must match before the dog clutch can be engaged. If the rotational speed difference of the shifting elements is too high during the engagement, the dog clutch is damaged. If torque is transmitted via the shifting elements of the dog clutch, the dog clutch cannot be disengaged.