A method for preventing a torque converter clutch that controls the slip
in a torque converter between a vehicle engine and transmission from
locking up in response to wheel slip from one or more of the vehicle
wheels. The method includes monitoring the vehicle speed and/or the
transmission output speed, and converting the speed to an acceleration.
An average of the acceleration is provided over a predetermined number of
sample points. The method then determines whether the current
acceleration exceeds the average acceleration by a predetermined amount.
If the current acceleration does exceed the average acceleration, then
the method causes the converter slip to be held at its current value so
that the torque converter does not lock up. Additionally, the method
prevents the transmission from changing gears. The method then monitors
whether the acceleration has fallen below a predetermined value or a
predetermined period of time has expired.