Ambient Air temp vs. Trans Temp?

mookdoc6 · August 7, 2018

Just curious.....what everybody is seeing on their DIC for Trans Temp when cold soaked before starting vs. the ambient air temp? It looks like I am +20 degrees colder than ambient? Problem maybe with fluid temperature sensor?

Grumpy Bear · August 7, 2018

1 hour ago, mookdoc6 said:

Just curious.....what everybody is seeing on their DIC for Trans Temp when cold soaked before starting vs. the ambient air temp? It looks like I am +20 degrees colder than ambient? Problem maybe with fluid temperature sensor?

Just a though. The trans and 12+ quarts of fluid is a big heat sink. By 4 AM or so the fluid and ambient are likely very close. By 6 or 7 am the air temp has risen but the larger heat sink taking longer to heat lags behind. Mine is behind some days and ahead some others. Never tried matching it to the evenings temperature cycle. There is this as well. The ambient sensor in my truck will go down 10 or so after being started and moving down the road. My Honda does that too. That sensor is very near the cowl and easy to bake.

Bryn7471 · August 8, 2018

I have the same problem. These photos were taken on June 26th in Tampa Florida. Temps never even get close to 59 degrees that time a year.

mookdoc6 · August 8, 2018

3 hours ago, Grumpy Bear said:

Just a though. The trans and 12+ quarts of fluid is a big heat sink. By 4 AM or so the fluid and ambient are likely very close. By 6 or 7 am the air temp has risen but the larger heat sink taking longer to heat lags behind. Mine is behind some days and ahead some others. Never tried matching it to the evenings temperature cycle. There is this as well. The ambient sensor in my truck will go down 10 or so after being started and moving down the road. My Honda does that too. That sensor is very near the cowl and easy to bake.

Yeah, probably to some extent especially with rapid temp changes ambient to garage etc. My problem was the garage never gets below 100f and just happened to notice the trans fluid @ 85f in morning?

Did not have to think much beyond that as it sat in 115f heat for 5-6 hours....I drove away only to realize that 86f after my stop watch hit 15 minutes it went to 82f? First out of pocket expense! Dang 64K harness costs 100.00 and have to buy fluid now 200.00........Could be worse I suppose?

mookdoc6 · August 8, 2018

2 hours ago, Bryn7471 said:

I have the same problem. These photos were taken on June 26th in Tampa Florida. Temps never even get close to 59 degrees that time a year.

You probably have the same failure of harness fluid temperature sensor as myself? Sucks....but could be worse and not too bad of a fix it seems?

Bryn7471 · August 8, 2018

Your right, it could be worse. I just hate the fact that I’m having trouble convincing the dealership that the sensor is reading incorrectly. They must think I’m stupid, but your fluid can’t be colder than ambient temperature by that much.

mookdoc6 · August 8, 2018

3 hours ago, Bryn7471 said:

Your right, it could be worse. I just hate the fact that I’m having trouble convincing the dealership that the sensor is reading incorrectly. They must think I’m stupid, but your fluid can’t be colder than ambient temperature by that much.

Yup, not after setting all night...I will install after I receive the harness and report back............

m3n00b · September 18, 2020

On 8/7/2018 at 5:23 PM, Bryn7471 said:

I have the same problem. These photos were taken on June 26th in Tampa Florida. Temps never even get close to 59 degrees that time a year.

I'm having the same exact issue right now. After sitting all night, ambient was 69F. I started my truck this morning before the sun came up and the trans read 39F. I also notice that it won't shift into 8th(or maybe lock up) on the highway until the sensor reads ~75ish. I'm also concerned about the trans thermostat. Is that controlled by this sensor or is it mechanical? I guess I need to get this fixed either way. No codes yet....