Ok, I've got a couple ideas but not sure if any of them are right. I hooked up exhaust brake/tc lockup from turbobrake.com. It's nos, had it on the shelf for a couple of years.
Anyhow everything seems to work, other than when it's in the accel lockup position. The trans doesn't seem to shift into OD (holds 2800 rpm @55) then the OD light starts flashing and I get a P1728 trans slip code. Along with a P0603 KAM code.
Normal driving with the switch in the ex brake mode and the shifts are better (doesn't drop rpm's like before under acc), seems to shift at normal speeds, and I don't throw any codes
When I delete it with the AE and restart the OD stays flashing until I leave the batts disconnected for a while. Any ideas?

 

sounds liek there is an internal problem with the brake box. it is causing a slip condition that you are associating with the lack of upshift into overdrive.

 

That's what I was thinking, guess if it works alright in the other modes I'll just disconnect the acc/lock up mode. Thanks!

 

still got a warrentee? if one component is toast how long before somethign else goes up?

 

It's probably long since expired. I've had it for a couple of years just never installed it. Can't get the website to open so maybe thery arn't in busines any more??