No. You have a problem when it doesn't unlock. GM had a huge problem with that in the '80s. The converter would stick and not unlock causing stalling at stop signs. The cheap fix was to unplug the connector for the lockup solenoid so it never locked and couldn't stick. That raised engine speed 200 rpm on the highway. Few people noticed the big drop in fuel mileage.
Yours is doing exactly what it is supposed to do. The only thing that can cause trouble is using the wrong transmission fluid. That can cause a harmless but irritating shudder for half a second each time it locks up. Again, the way to identify that is to cruise at a steady speed, then tap the brake pedal. Each time the converter locks up right after that, you'll feel the shudder if the wrong fluid is in there.
Another potential problem is caused by a dropout of the signal from the throttle position sensor. Usually that will set a fault code and turn on the Check Engine light, but if it occurs fast enough, it might not set a code. The clue is the converter will be unlocking intermittently when you're just moving the throttle a little bit. Normally you have to almost totally release the gas pedal before the computer knows you plan on coming to a stop. If you feel the unlocking with the cruise control set, the slight throttle adjustments it makes to hold the speed steady will cause the converter to unlock if there's a glitch in the throttle position sensor's signal. That's not real common. It seems to happen more on some diesel trucks.
Monday, March 12th, 2012 AT 3:10 PM