4t45e Torque Converter Not Staying Locked

[sparkplug]

Well if you read my last thread about my oil pressure gauge and the spinning of a bearing I have an 05 LA1 in my 03 Grand Am GT. So after the swap I noticed that my torque converter will not stay locked. When I drive it first in the morning it will shift fine and lock up. Then after a few minutes it unlocks and rpms go up. After a while it will lock but unlock again. Fluid level is ok, it's not brown or burnt. I have 94000 on the tranny. Can anyone tell me what the hell is going on here? I heard there was a PCM flash to correct this.

[robertisaar]

don't suppose you have a way of monitoring trans temp?

it sounds like the normal PCM unlocking of the TCC due to high temps, if so, pipe in an auxiliary trans cooler.

[sparkplug]

I don't have a way to checking the temperature. Will a code scanner be able to check the temperature?

[robertisaar]

a scanner would only work if it was able to read sensor values(most don't), unless the temps got high enough to set a DTC, then you would see it, but that's not likely.

[sparkplug]

I guess I'll have to add another cooler and go from there.

[bob442]

Could be a sticky valve, or maybe you damaged something when swapping the motor? Anyways, a scanner will tell you tcc apply pressure and slippage. Issues are known to happen with tcc on 4t45e/60e/65e. A cooler won't fix this.


Sent from my iPhone using my iPhone at work cuz I have nothing to do

[sparkplug]

So would a fluid and filter change help? Or do I need to replace the TCC? And I'm assuming http://www.rockauto.com/catalog/moreinfo.php?pk=1217365 thats what your talking about?

[geldartb]

GM did some upgrades to the valve body is 02-03 so you shouldn't see the issues that the previous years saw.

[3400-95-Modified]

Start with finding a way to monitor temps... then go from there. The sticky valve issue is knows for transmissions that have been neglected and caused excess wear on the valve body bores, at that mileage it doesnt sound like that should be the issue though.

The other thing to check is the trans pressure itself as well to ensure that is correct. I'm not sure what the testing procedure is for a 4t45e since its electronically controlled pressure vs my vac on my 4t60e.

[sparkplug]

Hmmmm. I was hoping it was something easy to fix. The car is under warranty and since I don't have access to a scanner to I"ll have to take it to the dealer.

[3400-95-Modified]

If it's under warranty why would you even want to think about taking on a transmission issue... Just bring it back and have them troubleshoot it or fix it.

[geldartb]

If it's under warranty why would you even want to think about taking on a transmission issue... Just bring it back and have them troubleshoot it or fix it.

i'm with him. if you can have someone else screw around with it and not have to pay then go that route.

[sparkplug]

I'd like to know for my own personal knowledge.

[geldartb]

save that for when the warranty runs out.

[sparkplug]

True.