ridenred333

First off let me introduce myself. I have been a Ford owner for years. I bought a 2010 suburban last month. It's the lt model 4x4 1500. It has 40k miles. I did put a Range technology fuel management deactivation device on. Ok, so let me start with this. I drove it from Alabama to Arizona this past week. I was pulling a 3k trailer and had about 300lbs of gear in the back. I had my first issue in Louisiana. Trans started running hot in stop and go on the highway. I was running tow haul mode the whole trip. It kick check engine light on and put me in limp mode. So i pulled off highway and disconnected the battery to reset computer. The rest of the trip in never did trip limp mode however it did heat up to about 205 temp. I dont have an owners manual so I dont know what temp is the safety temp. I plan to have an aftermarket trans cooler put on it. Anyone else run into this? Why would they run the cooler lines thru the radiator if the engine temp always runs at 210 then the radiator has to be close to this temp, which is being shared with the cooling part for the trans. Second question is I was driving it tonight and pulled out onto a busy street and for some reason stability track dinged then check engine came on causing limp mode so I pulled over disconnected battery an reconnected go back on road no issues. Anyone have this issue? I am really getting frustrated as this is my pretty new vehicle and doesnt really have that many miles. Is this a Chevrolet issue? I am almost to the point of trading it in already and i just bought it. I feel like I should have just stuck with Ford but I am really not a brand specific person. Any thought or idea's will be helpful. Thanks

SabrToothSqrl

why did you install anything? a 3k trailer is nothing.

I hauled a 6,000 lbs boat + 1k of gear + 700 lbs of fuel for 2 hours each way with freaking mountains in the way. in a completely stock 2009 Tahoe. (Ok, I do have LED tail lights).

that truck should have no issues what so ever with a 3k trailer. you should barely notice it's there.

You don't have to do that kind of stuff. the truck is designed to tow... I'm really at a loss of understanding why it would need to be modified.

Did it exhibit any of these behaviors before it was modified?

intheburbs

Dexron VI transmission fluid, which is what's in your Burb, is capable of operating at much higher temperatures with minimal breakdown in properties. 205° on the transmission is slightly above normal operating temps, which are 180°-200°.

I just returned from a 5,000 mile trip pulling a 7,000-lb travel trailer. Gross weight of my rig was right around 14,500 lbs. It was a trip out west, through the Rockies, including a drive through the Eisenhower tunnel (11,300 ft altitude). Highest the transmission got was 230°. I was not concerned.

No need to install an aftermarket cooler. The stock cooler is just fine. I have several friends here in MI that work for GM, including one who's a transmission engineer that works at GM's test lab. Dexron VI can go as high as 270° before suffering any real breakdown in properties. After I got back from my trip, I pulled the transmission dipstick so see/smell/feel the fluid. I also cracked a new bottle of Dexron VI for comparison; other than some discoloration, which is normal, the two fluids smelled and felt the same.

I'm assuming the "Range technology fuel management deactivation device" is to disable AFM? One of the reasons I have a 2500 - no AFM on the 6.0.

ETA: Here's a link to download your owners manual: CLICK TO DOWNLOAD

ETAA: Here are my gauges as we approached the tunnel - 4,000 RPM, 2nd gear, 40 MPH, engine at 220°, trans at 230°, ambient temp at 78°:

ridenred333

Because the fuel management system on these vehicles are junk and this deletes it. I have ran with and with out it same results the delete has nothing to do with trans temps. The only thing it does it stop if from going back and forth between v4 and v8. Which is annoying in itself.

I know the trans isnt hot at 205 I just dont know why it would trip to limp mode between 205 and 210..

In the burbs thanks for sharing the owners manual with me.

in2pro

ridenred333 Welcome to the forum...

I don't think the temp tripped the check engine light, something else did and you have erased that code by disconnecting the battery... get a code reader and read those codes first, don't clear indiscriminately!

205 is not bad for a short period... before installing my aux trans cooler I was getting temps close to 220....with a 2000lb pop up going through Colorado...

And for clarification as I understand it, the engine operates at 210f and the thermostat opens at 195 and closes as needed to maintain that temp... the coolant in the radiator is NOT at 195 or 210 it is cooler due to air flow, that is its job to provide "cold" coolant for the engine to maintain that temp.
The transmission also releases heat to that lower temp coolant...the radiator does not heat up the transmission fluid to 210 that would counterproductive...

Do add that aux cooler it will help a great deal...FYI the aux cooler still pipes fluid through the radiator...

73shark

One of the reasons for this is to prevent "slushing" the ATF in very cold temps as Chrysler found out on their minivans when the optional tranny cooler was added and the driven in Minnesota in the winter.

ridenred333

What code reader would you recommend. Like I mentioned before I am new to chevrolet so I don't know if one brand is better than another or not. Thank you for the information it is greatly appreciated.

tech2

I'm wondering if both incidents were related to a drive by wire/throttle body concern, not a trans temp issue. This will set both traction and ses lights. There was a recall for this. Get the codes read and post them here. The codes will still be in history. I understand autozone will read them for free. have them check the ecm, tcm and ebcm for codes.


if you do decide to install and aftermarket trans cooler...route it into the cooler first then into the rad...do not bypass the rad.

73shark

I use one by Actron. On the road so I can't tell you the model but gave about $80 for it 15 years ago.

in2pro

ridenred333
It will depend on what you want to spend, but if you are anything of a DIY'er you should invest in one that will read the code and give a general description of what the code is...
You may not use it often maybe months or years but it can be very handy to have, I keep mine in the rear storage compartment with my jack, jumper cables and a quart of oil in a zip lock bag...
I have the Actron CP9180 that I also got several years back, it has the ability to record data and play it back or dump to a PC...
You can get one that will simply display the code and allow you to reset it for ~$40 but for $250 or so you can get more detail and some function features like activating EVAP system and the like...

Like Tech2 I also suspect a throttle body or throttle position sensor or accelerator pedal position sensor issue as those are most likely to put you in a limp mode... often times just shutting the vehicle off, removing the key and waiting a few minutes will also take the vehicle out of limp mode until the error comes up again...