2013 Silverado Tranny Overheat in Park !

[wxfield]

Originally Posted by j cAT

do you have electric fans or mechanical fan ?

Oh, wait. I think I see why you're asking if it has electric fans. You think that there is some trigger temp that the computer will turn on (or up) the cooling fan to pull more air over the transmission core.

[Tech II]

I use my truck for business too.....what's the advantage of letting it idle for half an hour wasting gas? You have a business.....a smart business guy saves money any way he can.....shut it off....

[wxfield]

Originally Posted by Tech II

I use my truck for business too.....what's the advantage of letting it idle for half an hour wasting gas? You have a business.....a smart business guy saves money any way he can.....shut it off....

Like I said, Thank you for the suggestion on how I conduct my business. There are reasons we would keep the truck running in park however. None of which make any sense in explaining why the transmission should get so hot during idle.

[j cAT]

Originally Posted by wxfield

Electric.

the electric fans are whats doing this. when the vehicle idles the temp will rise to a higher than normal temp . then the fan will come on at this higher temp ..the transmission fluid sensor will show a higher temp because of the coolant being hotter because with the electric fans you get no air flow until the temp gets to a higher amount.

when you idle and then see this temp rise put the ac on. this will I believe put a fan on and the temp will drop...

I have these type issues with my 1996 impala. the fan comes on when the temp is about 230 deg f .this does cause the under hood temps to be too hot for my liking.. most have their PCM/computer programed so the fans come on sooner like 212 deg f instead of the 230 deg f...

with the mechanical fans you do not have these idling hi temp issues..

[wxfield]

Originally Posted by j cAT

the electric fans are whats doing this. when the vehicle idles the temp will rise to a higher than normal temp . then the fan will come on at this higher temp ..the transmission fluid sensor will show a higher temp because of the coolant being hotter because with the electric fans you get no air flow until the temp gets to a higher amount.

when you idle and then see this temp rise put the ac on. this will I believe put a fan on and the temp will drop...

I have these type issues with my 1996 impala. the fan comes on when the temp is about 230 deg f .this does cause the under hood temps to be too hot for my liking.. most have their PCM/computer programed so the fans come on sooner like 212 deg f instead of the 230 deg f...

with the mechanical fans you do not have these idling hi temp issues..

This all makes sense now. This is the first truck I've owned where there are electric fans in it. The funny thing is that when this tranny temp scenario first happened I noticed the water coolant temp also ticked a bit to the right of 210 degrees (which is the normal coolant operating temp). I tried blasting the heat in the cabin to see first if I could drop the water temp, and that worked..but the tranny temp kept rising, so I shut it all down.

Great advice on the AC, this is also one of my few trucks that came with AC..I'll give that a shot and see what happens. At least with the clutched mechanical fans you always had airflow..not sure I like the electric fans.

Did you ever look into reprogramming your fans to come on at lower temps to keep things cooler?

[j cAT]

Originally Posted by wxfield

This all makes sense now. This is the first truck I've owned where there are electric fans in it. The funny thing is that when this tranny temp scenario first happened I noticed the water coolant temp also ticked a bit to the right of 210 degrees (which is the normal coolant operating temp). I tried blasting the heat in the cabin to see first if I could drop the water temp, and that worked..but the tranny temp kept rising, so I shut it all down.

Great advice on the AC, this is also one of my few trucks that came with AC..I'll give that a shot and see what happens. At least with the clutched mechanical fans you always had airflow..not sure I like the electric fans.

Did you ever look into reprogramming your fans to come on at lower temps to keep things cooler?

on my 1996 I would have to ship my PCM to the programer guy. I wish they made a programer for my vehicle .. your vehicle you may be able to buy a programer to do this type adjustments . some with your vehicle type also remove the AFM . this they find uses a little more fuel but the transmission works better/smoother.

I do not have the OEM manual for your truck . I do not know what the temp would be to get the fan to come on.. I will see If I can find it as I do have some sections of the new OEM shop manual..

[wxfield]

Originally Posted by j cAT

on my 1996 I would have to ship my PCM to the programer guy. I wish they made a programer for my vehicle .. your vehicle you may be able to buy a programer to do this type adjustments . some with your vehicle type also remove the AFM . this they find uses a little more fuel but the transmission works better/smoother.

I do not have the OEM manual for your truck . I do not know what the temp would be to get the fan to come on.. I will see If I can find it as I do have some sections of the new OEM shop manual..

Wow! That would be great if you can find something..but don't go to a lot of trouble. The service manual the dealership provided me in a previous post seems to hint that 200 degrees is the top range for trans temp. I can always take this to my mechanic and ask for his help too. He's been really good over the years in keeping my fleet of vehicles on the road. I wonder in your case if it's worth the effort to have a re-programmed PCM sent to you in exchange for your old one.

[j cAT]

Originally Posted by wxfield

Wow! That would be great if you can find something..but don't go to a lot of trouble. The service manual the dealership provided me in a previous post seems to hint that 200 degrees is the top range for trans temp. I can always take this to my mechanic and ask for his help too. He's been really good over the years in keeping my fleet of vehicles on the road. I wonder in your case if it's worth the effort to have a re-programmed PCM sent to you in exchange for your old one.

I found this not sure if it correct but seems right ;

The fan relay will be commanded on when ECT reaches 223°F (106°C) or greater, A/C is requested or vehicle speed is less than 38 MPH.

[wxfield]

Originally Posted by j cAT

I found this not sure if it correct but seems right ;

The fan relay will be commanded on when ECT reaches 223°F (106°C) or greater, A/C is requested or vehicle speed is less than 38 MPH.

Great information, Thank You !

Do you have any opinions in regards to programmers? It seems I'm just interested in programming a few values (like the electric fans) to come on sooner.

I may ask my mechanic too. It's possible he has the ability to program different values for this truck and may have an opinion about doing that.