Proper Operation of Tranny

07texas Titan · 11-24-2008, 04:45 PM

Have a question about the proper operation of tow haul mode.

Have 07 Titan Crew Cab SE and when in Normal mode in 5th going down hill large or small and touch the brakes the truck down shifts and engine brakes.

However in Tow Haul mode I do not get the engine braking. Have asked dealer about this repeatedly. "No problem found trans working as it's supposed to" but when asked "Ok then how is it supposed to work am I supposed to get engine breaking in tow haul mode? In normal mode? In neither or both? " they dnon't know.
So my question is two part:

Do your trucks trans brake in Normal Mode?

Do your trucks trans brake in Tow Haul Mode?

Does it engine brake in both or 1 of the 2 only?

Thanks in advance for your assistance.

Cliff

**helomech** · 11-24-2008, 04:48 PM

Quote:

Originally Posted by 07texas Titan

Have a question about the proper operation of tow haul mode.

Have 07 Titan Crew Cab SE and when in Normal mode in 5th going down hill large or small and touch the brakes the truck down shifts and engine brakes.

However in Tow Haul mode I do not get the engine braking. Have asked dealer about this repeatedly. "No problem found trans working as it's supposed to" but when asked "Ok then how is it supposed to work am I supposed to get engine breaking in tow haul mode? In normal mode? In neither or both? " they dnon't know.
So my question is two part:

Do your trucks trans brake in Normal Mode?

Do your trucks trans brake in Tow Haul Mode?

Does it engine brake in both or 1 of the 2 only?

Thanks in advance for your assistance.

Cliff

I don't think the tow mode works in 5th.

HudsonValleyTitan · 11-24-2008, 05:51 PM

Quote:

Originally Posted by 07texas Titan

Have a question about the proper operation of tow haul mode.

Have 07 Titan Crew Cab SE and when in Normal mode in 5th going down hill large or small and touch the brakes the truck down shifts and engine brakes.

However in Tow Haul mode I do not get the engine braking. Have asked dealer about this repeatedly. "No problem found trans working as it's supposed to" but when asked "Ok then how is it supposed to work am I supposed to get engine breaking in tow haul mode? In normal mode? In neither or both? " they dnon't know.
So my question is two part:

Do your trucks trans brake in Normal Mode?

Do your trucks trans brake in Tow Haul Mode?

Does it engine brake in both or 1 of the 2 only?

Thanks in advance for your assistance.

Cliff

According to Nissan, Titans don't have any sort of hill descent feature although us owners know better. Tow/Haul mode ony changes shift points in the first 2 gears. It doesn't change anything else that I've even been aware of. If you're towing in 4th like you're supposed to, that may be the difference. It may not engine brake unless it's in D. But no, it doesn't sound like anythings wrong.

**loufish** · 11-24-2008, 09:55 PM

I've tried all sorts of different things with the T/mode and the only thing I can say for sure is....what everybody spits out..."Raises shift points on the first 2 shifts...after that there is no evidence that the T/Mode does ANYTHING else"

I do use it around town to keep the trans from short-shifting, but once on the road use it, don't use it, it makes no difference...

I've voice-ed my discontentment of Nissans T/Mode operation many times before...

07texas Titan · 11-25-2008, 07:40 PM

Loufish

Can you try a test for me?
While going down a hill approx 20mph in normal mode in 5th touch your brakes.... do you notice the truck dropping a gear and engine braking? If it does try it again in tow haul mode tranny in 5th and see if she engine brakes.
I have service manger in CT in an uproar because I bashed his service dept on the written servey so he is pulling in all favors trying to get a proper description of how the tranny is supposed to operate. AKA and get me off his ARSE about this issue.
Would love to have some comparisons to run by him first. If he gets a fix will let you all know as soon as I do.

Note another side affect is engine braking will give you that back and forth jerking motion when you let off the gas then reapply the gas because she keeps the torque converter locked up. (like in a standard shift).

Learjet · 11-30-2008, 08:00 AM

see the attachment for the shift points with and without tow mode. I do feel some engine braking sometimes, I would say it is when the Torque converts doesn't unlock right away due to certain unknown parameters.

**Carbeaux** · 11-30-2008, 08:22 AM

Quote:

Originally Posted by Learjet

see the attachment for the shift points with and without tow mode. I do feel some engine braking sometimes, I would say it is when the Torque converts doesn't unlock right away due to certain unknown parameters.

That's an interesting doc. Where'd you come across that? Gotta admit I'm curious.

Learjet · 11-30-2008, 08:29 AM

Quote:

Originally Posted by Carbeaux

That's an interesting doc. Where'd you come across that? Gotta admit I'm curious.

Nissan service manual for the transmission.

**loufish** · 11-30-2008, 12:11 PM

Quote:

Can you try a test for me?
While going down a hill approx 20mph in normal mode in 5th touch your brakes.... do you notice the truck dropping a gear and engine braking? If it does try it again in tow haul mode tranny in 5th and see if she engine brakes.
I have service manger in CT in an uproar because I bashed his service dept on the written servey so he is pulling in all favors trying to get a proper description of how the tranny is supposed to operate. AKA and get me off his ARSE about this issue.
Would love to have some comparisons to run by him first. If he gets a fix will let you all know as soon as I do.

Note another side affect is engine braking will give you that back and forth jerking motion when you let off the gas then reapply the gas because she keeps the torque converter locked up. (like in a standard shift).

I get the downhill engine braking when i just touch the brakes ...sometimes. I say sometimes because I can't get it to happen the same way every time...But when it happens I do feel it...I don't remember reading about it in any of Nissans literature. I'll try it with T/M on and off and see what happens....

**J.Bahde** · 12-06-2008, 05:11 PM

I recently took a trip to the mountains of east Tennessee and was doing a lot of manual shifting with the rocker switch on the end of my shifter for three days (I didn't notice any difference using tow mode), but when I got back on straight roads I put it in OD like I normally would drive, and for the rest of that day the engine was braking much more than I have ever noticed before. It would brake when I let off the gas and tapped the brakes. That only lasted for a couple days, now it dosen't brake like that any more, it just drives normal again now. I don't know if doing all that manual shifting caused that or not.

Leadsled124 · 12-06-2008, 06:58 PM

I think you have to be going downhill (picking up speed) and tap the brakes 2 times without touching the gas pedal to get it to downshift. Im not sure about t/h mode but ill try it next time

**J.Bahde** · 12-06-2008, 08:57 PM

So I was driving the Titan tonight and started pushing the tow mode button. I noticed that when I take it out of OD and then push the tow button, the light on the tow button dosen't come on, but if I push the tow button when it's in OD the light comes on, and stays on even if I take it out of OD, but only comes on if I push it when it's in OD. Anyone else noticed this?

HudsonValleyTitan · 12-07-2008, 09:59 AM

Quote:

Originally Posted by J.Bahde

So I was driving the Titan tonight and started pushing the tow mode button. I noticed that when I take it out of OD and then push the tow button, the light on the tow button dosen't come on, but if I push the tow button when it's in OD the light comes on, and stays on even if I take it out of OD, but only comes on if I push it when it's in OD. Anyone else noticed this?

On both my Titans, that tow mode button light stayed lit until the truck was shut off or I turned it off myself. It doesn't care what gear the shifter is in.

**J.Bahde** · 12-07-2008, 10:32 AM

Thanks for the reply, I may bring mine to the dealar to make sure everything's ok. Hopefully if something is wrong it will be covered under the powertrain warranty.

HudsonValleyTitan · 12-07-2008, 12:01 PM

Yeah that doesn't sound right since you're supposed to use the tow mode while in 4th anyhow. I'd double check to see if you're right then have the dealer look at it. Let us know what they find.