98 T/A TCC Lock-up

[JonRussell18]

For some time now my car will drive fine, and once it has some temp in it. It'll lock up the converter clutch. After a few miles or so it'll just randomly unlock and won't lock back. It has no problems when it is locked up feels fine. No codes or anything being shown. I got HP Tuners recently and I wanna address this problem. I'm a noob when it comes to this so forgive me.

Rundown on the car:
SBE LS1, 227/235 .619/.606 110+3, Stock heads, Ported Fast 92, PTM 92mm Throttle Body, Headers, True Duals, Performabuilt Level 2 4L60e, Yank SS3600 Single Disc.

Here's the tune that was done a few months back after I had it dyno tuned locally. Any help is much appreciated!

[fst100]

im not on my tuning laptop with hptuners but i noticed you have an aftermarket higher stall converter and depending on if your pcm is tuned yet or not, may be the culprit.

[RDF1]

You should be able to monitor why its unlocking if its in the tune. Id have to connect to a pcm and find the channels tho.

Look up all the TCC channels and see if any of them show you why its happening

[Alvin]

While it is acting up scan it to see if there is a P0741 pending. This is acts exactly like that.

The tune looked OK from a quick glance.

[JonRussell18]

It's been tuned for the converter. And the last drive while scanning, the TCC Mode went from Locked straight to off for seemingly no reason. TPS was at 5% doing around 65mph. And it didn't try and apply it for the rest of the drive. I looked at my DTCs and the P0741 is turned off in the tune. I checked it back and will go for another drive.

Edit: I drove it, and scanned the DTCs while driving and the only pending code I have is a MAF code. I'm tuned in speed density so I suspect that's why that pops up. I monitored the TCC mode and it never changed from off. Never said Apply/Locked or '--- 3 ---"

[JonRussell18]

I wanna bump this just in case someone has a similar issue. After Facebook groups and other forums suggest misfire detection in the tune and that not helping in the least. I logged the car again with more PIDs and discovered the pressure manifold switch that includes the trans temp sensor is faulty. It pegs the sensor at 5 volts and -36 degrees. And once in the log it was reading 97 degrees and 1.43 volts like it should and the TCC mode was set to "---3--" which I've read means that the TCC is ready to be locked. So if anyone has issues with a TCC lock up intermittent issues, log the trans temp sensor.