Trans Lock Up Converter

[patrari]

Hello I have a 93 gmc 4x4 1ton 7.4 with a 4l80e and my lock up convertor locks up intermitily while at cruising speeds 65 70. I will be going along and it will lockup and unlock for a split second. Any idea how to trouble shoot this to figure out what is causeing this. Other wise the trans works like it should.

[2000CAYukon]

Most likely valve body wear.

http://www.sonnax.com/announcements/34994-01K.pdf

//2000CAYukon

[patrari]

Is there any way you coyuld give me more info on this? and if you can can u explain it to me please and thank you. went to website thanks

[maxwedge]

The pcm controls the application of the tcc based on tps, speed and engine load inputs, the valve body issue may not apply to your year. A full scan will look at whether the listed functions are within operating range, an improperly adjusted stop lite switch could cause this also.