Hey guys I have an 04 1500 5.3 crew cab with a built 4l60 with a yank ss3600 converter.
The past few days it has been fairly cold between 33-50* out and my converter will take a while to lock up. After the first lock up, it is fine for the rest of the day. It is just on the first cold start of the day. I was thinking it might be the whole PCM won't let the converter lock up because it's too cold thing, but this morning when I went to work, around noon, it was 70* outside and it still would not lock up on the cold start. Any ideas?

 

There is a parameter in the tune that prohibits TCC lockup until a designated trans fluid temp is reached. Without a trans temp gauge or a scanner to show trans temp, its kind of hard to say for certain if that is it or not.

 

I have a trans temp gauge but it rarely every gets over 100 on a cold start in the morning. I don't know if it's helpful or not, but the converter seems to lock when the engine coolant temp gets to the first dash above 160*. Now where the trans temp is at this time I have no idea because it doesn't warm up until a while after.

Thanks,

Erik

 

Update.. Just drove it back to work and now, no lockup at all. It was at running temp and trans temp was around 150*. No check engine lights.. Could this be a solenoid?

 

i have that same problem.. but like stated above dont know if its the tune.. but when it gets cold i drive it and it wont lock up... after running temp it will... maybe its a tcc selenoid not sure.. do you have a Check engine light?

 

No CEL. If the rain will stop, I just picked up a new tcc pwm solenoid I will change out. What about the brakelight switch? If that was going out wouldn't the brake lights be on all the time?

 

Yes. The brake light switch can also affect your ability to lock up. The trans is supposed to unlock the converter when it see's the Signal from the brake light switch.

 

x2 theres a way to by pass it but dont remember... i think they are 2 pink wires or yellow under the dash not sure but ill find out.. that way you know if its that for sure..

 

TCC engagement is disabled if the fluid temp is below 68*F.

The brake pedal switch is a two stage switch, it has a NC and NO outputs. So if the switch goes bad you can get an open on the TCC circuit but not a closed on the lighting circuit.

 

My built 4l65e and yank tt3000 is the same way..on cold days (<40* or so) I don't get lockup until everything warms up..I asked Justin about it in the tune and its basically a safety precaution..but like you said, once its warm, I'm normally good for the rest of the day, unless its below 0* and it has to warm up again..Been like that for 3 years or so