Torque Converter Shifting in/out of lockup

[BigDogIDI]

I recently had the transmission (e4od) rebuilt on my 1992. I had an upgraded torque converter installed too. My TC has been shifting in/out of lockup randomly. It will lock and unlock (every 2-3 seconds) for a couple minutes, then I won't have an issue for 10 minutes or so. I cleaned up where the tach sensor connects to the wiring harness and also where the harness plugs into the TPS. (Both checked out with a multimeter test...) This didn't seem to make a difference. Any ideas?

 

[Ddizzy77]

Might want to disconnect the batteries for an hour or so. See if it keeps doing it.

 

[79jasper]

Check the brake light switch.

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[retiredinhomer]

I recently had the transmission (e4od) rebuilt on my 1992. I had an upgraded torque converter installed too. My TC has been shifting in/out of lockup randomly. It will lock and unlock (every 2-3 seconds) for a couple minutes, then I won't have an issue for 10 minutes or so. I cleaned up where the tach sensor connects to the wiring harness and also where the harness plugs into the TPS. (Both checked out with a multimeter test...) This didn't seem to make a difference. Any ideas?

what was the idle voltage on the tps? I have mine set for 1.12vdc it changed the whole shifting pattern .

 

[Double-S-Diesel]

check all you lights including parking lightts and 3rd brake lite
had a 96 that the liscensce lite was out and that caused an isssue
also had a 02 van with the 3rd brake lite out do that
other thing to look at is trailer brake control id installed, had one in a 97 that was causing an issue

 

[BigDogIDI]

My pickup doesn’t have a third brake light.... all the other lights work.

 

[trackspeeder]

Check the TPS again. The voltage should go up and down gradually with no funky readings.

 

[Sidewinded_idi]

Replace your tps. Mine was doing that when it had an internal short. It would test fine through setting with a multimeter but the vibrations going down the road it would lose connectivity and make it think you let off the gas and unlock the converter