Can cold weather change the way TCC locks up? I had an evap problem and replaced all the vacume lines and associated hardware. Except for the charcoal canister. I haven't had any problems with the evap system since, but the trans has been acting funny. TCC hasn't been engaging as it usually does. This seems to have started after the evap system problem showed up. It seems to do it more when it is cold, but even after running for a little while with TCC locked up it will just kick out. Even on level ground with the cruise set at 70.

Thanks for any help.

so it still goes into 4th gear just fine? and the TC locks in 3rd?

it goes into gear just fine. the tcc just doesn't lock up all the time. i am starting to think this has more to do with the cold weather than anything. as the car warms up the tcc locks up. just curious if this had happened to anybody else.

Is your thermostat controlling the motor temperature at a normal temp?

Here it'* been brutally cold some days and I can cool the motor back down with motion through the cold air and with the heater pulling lots of heat out of the coolant circulating through it. I wonder if your coolant temp is going cool and the TCC unlocks to run the motor faster and heat it back up. I assume after a while it acts okay again?

Ever replaced the thermostat?

Sorry it has taken me a while to get back, things have been hectic.

I have replaced the thermostat, with a 180*. It has warmed back up around here and the car is back to normal. I think it was just running cold and kicking out of lock-up to try and warm the engine.

Thanks.

It was -15° on the way in to work this morning and I did not get lock up. I was doing 50 mph and the motor was ~150°. The shifter was in "D" and I was showing 1750 RPM'*.

I thought it went by the trans fluid temp?