Hi, I am new to this site. I have a 94 bonneville, and when cruising, the chime will go off and speedometer will zome up, like the tranny has come out of gear. Can let off the throttle, and it will come back and do fine. It shoots a P0740 code. It acts to me as if its an electrical problem. I took pan of this weekend, and everything looked fine, when I changed filter. Would appreciate any and all help in this matter.
Thanks guys,
Steve

P0740 code is Torque Converter Clutch (TCC) problem. This code is displayed when the TCC is commanded "ON" by the Powertrain control module and the engine rpm/vehicle speed ratio indicates that the torque converter is not locked. May be a problem with the wiring to the trans or the tcc solenoid. Could also be other internal trans problem.

Flatlander

Don't know if yours is the same problem, but my '95 would not stay in lockup when hot. I got great results by adding an auxiliary trans cooler. Here is the thread: http://www.bonnevilleclub.com/forum/...ic.php?t=59874

more info on the code:

Hello,

I have the exact same problem. I was wondering if adding a cooler was a permanent fix. Thanks!
PS: I cannot open the link you provided...

Hey, I'm curious about this too. I'm getting that surging associated with the TCC but primarily after the vehicle warms up. A tranny radiator is pretty easy to install and only about 40 bucks. Did this help out your issue permanently?