My other caddy is pulling a code 39 whenever I get on the highway and the torque converter fails to go into lockup (39 indicates VCC problem) been doing this for a long time, otherwise the trans is fine, shifts firm and all. Pulls down the gas mileage around 4mpq which is frusterating given these high prices. I heard of an updated prom for this car came out 1998 that may correct this problem. Thinking about taking the 40 dollar gamble and trying this fix. Anybody familiar with this? Could just popping a new chip in the computer correct this problem? If it is a bad soliniod in the trans, think I'll just leave it alone as I understand the whole trans would have to be removed for this, might as well just rebuild it at that point with all the work involved just to get to the solinoid, the car has 123k on it, like I said runs and shifts fine, only complaint is gas mileage with no lockup, put a piece of tape over the check engine light so it does not bother me.

Edited to Add, Thinking about maybe trying a trying a Fastchip in this car, anybody have any experience with these http://www.fastchip.com/ For 159 bucks, I would loose the speed limiter, gain performance and hopefully correct the TCC lockup problem. Now just gotta find where the chip is located, I think a while back someone told me it was on the pass side near the a/c heating ducts?

I have a 95 4.6 liter with the P039 problem, what did you end up doing?

Pretty much nothing, when i talked to the dealer about getting a computer chip with larger tolerances relating to lockup slip they looked at me like I was crazy. then I called fast chip and they say there chips have the same lock up slip tolerances as stock so installing their chip would not fix this problem. Best solution I come up with for this problem is black electrical tape covering the check engine light. When the trans dies, I will address the problem then, but that may be another 50k miles or more, it shifts fine now. I may try some lucas trans treatment and see if that helps out although probabley it wont.