Thread: Repeated TCC lock/unlock with no PCS readout

I put a used transmission into my car last week and have noticed that on the highway or anytime the torque converter is supposed to be locked, I get an oscillating lock/unlock at 10-15% throttle. More throttle keeps it unlocked, and less lets it stay locked.

Upon scanning, I noticed that my PCS current was 0.00 A and the line pressure was frozen at 38%. Could I have a bad connection at the 20-pin plug, or could the PCS be completely dead?

BTW, donor car supposedly drove perfectly fine, but blew head gasket and overheated (I helped tear the engine down). This was over a year ago.

I really need some help with this one! It's driving me crazy.

I did see that the PCS current was changing today, but the line pressure percentage was still stuck at 38%. I have a few scans if someone wants to take a look at them.

The torque converter unlocks and stays unlocked if I touch the brakes while cruising.

I'll post the scans here shortly.