Stupid question: what exactly does Tow/Haul mode do on 2013 Escalade ESV?

[skpyle]

Hello All!

I have what is likely a VERY stupid question: what exactly does the 'Tow/Haul' mode do in my 2013 Escalade ESV?
I am assuming it alters the shift timing and characteristics of the 6L80E transmission?
I have read section 9 in the Owner's manual, it discusses Tow/Haul some, but I am missing something. Or I am just dense. Which is always a possibility.

This is mainly an academic curiosity. I have not, nor intend, to tow more than a small single axle trailer with a lawn tractor on it. Nowhere near the max trailer weight of 7,700lbs my Escalade is rated for.

Thanks for your time!

 

[rockola1971]

Tow/Haul Mode accesses a specific map in the PCM for shifting patterns and input characteristics while towing. It also prevents hunting back and forth when just over the top of one gear and into the next. This was a common problem in the 4L60E/65E/80E trannys. While towing in 4th (OD) the tranny would hunt back and forth between 3rd and 4th gear depending on weight hauled/incline/throttle position. It didnt end well for the 2-4 band. It would burn the 2-4 band up prematurely and dish the input drum where the band grabs to hold it stationary. Very common for the TH700R4 and 4L60 which is the great grandfather of the 4L60E/65E.

 

[Rocket Man]

You are correct, it changes the shift characteristics of the transmission. There may be more than that with your particular vehicle/ trans combination, I’m not sure. I know on the 4l60’s that’s all it does.

 

[skpyle]

You are correct, it changes the shift characteristics of the transmission. There may be more than that with your particular vehicle/ trans combination, I’m not sure. I know on the 4l60’s that’s all it does.

Thank you!
The more I read the owner's manual over and over again, it sorta makes sense. However, I am interested in the real world knowledge of you guys.

 

[skpyle]

Tow/Haul Mode accesses a specific map in the PCM for shifting patterns and input characteristics while towing. It also prevents hunting back and forth when just over the top of one gear and into the next. This was a common problem in the 4L60E/65E/80E trannys. While towing in 4th (OD) the tranny would hunt back and forth between 3rd and 4th gear depending on weight hauled/incline/throttle position. It didnt end well for the 2-4 band. It would burn the 2-4 band up prematurely and dish the input drum where the band grabs to hold it stationary. Very common for the TH700R4 and 4L60 which is the great grandfather of the 4L60E/65E.

Ah! That makes sense. Thanks!
(Hmmm...maybe I should not be towing the aforementioned trailer anymore with my little '84 S-1 with its GMPP HT3400 crate engine and TH700R4.)

 

[swathdiver]

Hello All!

I have what is likely a VERY stupid question: what exactly does the 'Tow/Haul' mode do in my 2013 Escalade ESV?
I am assuming it alters the shift timing and characteristics of the 6L80E transmission?
I have read section 9 in the Owner's manual, it discusses Tow/Haul some, but I am missing something. Or I am just dense. Which is always a possibility.

This is mainly an academic curiosity. I have not, nor intend, to tow more than a small single axle trailer with a lawn tractor on it. Nowhere near the max trailer weight of 7,700lbs my Escalade is rated for.

Thanks for your time!

I've engaged it when unladen or lightly laden and it holds the shifts longer and feels funny. When towing over 5K pounds, the shifting feels just right, there's no benefit to it unless you are within 75% of your GCWR of 14,000 pounds. Well, if you have the "hotel" wire hooked up, when tow/haul is engaged it sends power back to the trailer to power its internal lights, refrigerator, etc. If you leave it connected when you shut the engine off, it will continue to draw power. Of course, this does not apply to the lawn trailer, you would be using a 7 to 4 pin adapter which only works the running lights and signals.

How does the transmission feel after the upgrades?

 

[rockola1971]

Ah! That makes sense. Thanks!
(Hmmm...maybe I should not be towing the aforementioned trailer anymore with my little '84 S-1 with its GMPP HT3400 crate engine and TH700R4.)

700R4 is fine to tow with. Just keep it in 3rd and it will never hunt back and forth between 3-4. Put it in 4th(OD) and it will hunt and eventually burn the 2-4 band up. A corvette servo helps tremendously with this problem.

 

[skpyle]

I've engaged it when unladen or lightly laden and it holds the shifts longer and feels funny. When towing over 5K pounds, the shifting feels just right, there's no benefit to it unless you are within 75% of your GCWR of 14,000 pounds. Well, if you have the "hotel" wire hooked up, when tow/haul is engaged it sends power back to the trailer to power its internal lights, refrigerator, etc. If you leave it connected when you shut the engine off, it will continue to draw power. Of course, this does not apply to the lawn trailer, you would be using a 7 to 4 pin adapter which only works the running lights and signals.

How does the transmission feel after the upgrades?

Excellent, thank you! Correct, I am running a 7-4 pin adapter. Lights on the trailer only.

Transmission feels great! Granted, it is not end of the world different, but it feels better. Shifts are tighter and firmer. More pronounced when I put my foot in the water pump.
However, now I am getting antsy about the torque converter. Mileage is around 127,800. Just a shade under 4000 miles on the transmission after the upgrades and fluid exchange. I saw no metal in the pan, but she is at the age where the torque converter clutch starts to go. I am within a month or two of paying off the vehicle loan. After that, I will have money freed up. However...I have a 2 year powertrain warranty on the vehicle. I am on the fence: do I go ahead and pull the transmission for a new Circle D torque converter and engine rear main seal now? And possibly void the warranty? Or, wait it out until the transmission goes south, and hope the warranty does right by me...

 

[skpyle]

700R4 is fine to tow with. Just keep it in 3rd and it will never hunt back and forth between 3-4. Put it in 4th(OD) and it will hunt and eventually burn the 2-4 band up. A corvette servo helps tremendously with this problem.

Makes sense. I usually left it in 3rd when pulling the trailer. The GMPP HT3400 is stronger than the original 2.8L, but it is still a V-6, and the transmission is the original V-6 spec trans. Though I had it overhauled when I put the crate engine in. I have always tried to drive like I had some sense while towing.

Thanks!

 

[Geotrash]

Excellent, thank you! Correct, I am running a 7-4 pin adapter. Lights on the trailer only.

Transmission feels great! Granted, it is not end of the world different, but it feels better. Shifts are tighter and firmer. More pronounced when I put my foot in the water pump.
However, now I am getting antsy about the torque converter. Mileage is around 127,800. Just a shade under 4000 miles on the transmission after the upgrades and fluid exchange. I saw no metal in the pan, but she is at the age where the torque converter clutch starts to go. I am within a month or two of paying off the vehicle loan. After that, I will have money freed up. However...I have a 2 year powertrain warranty on the vehicle. I am on the fence: do I go ahead and pull the transmission for a new Circle D torque converter and engine rear main seal now? And possibly void the warranty? Or, wait it out until the transmission goes south, and hope the warranty does right by me...

It's the AFM engage/disengage that causes most of the problems with the TC lockup clutch on these. Since you have AFM disabled (you do, right?), I would be inclined to wait until your extended warranty is up. I still have the original transmission and TC in my 2007 (no AFM), and am coming up on 220K.