Tow/Haul Mode Not Functioning Correctly
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Junior Member
Joined: Apr 2009
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Thanks NorCAl for the information. I will try it again before bringing it back in now that I know it should function without a load as well.
5 Year Member
Joined: Mar 2009
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From: The Great Midwest, aka, Flyover Country
I've found that my '09 will actually downshift into a lower gear automatically when I'm cruising on the X-way with the cruise control engaged--without the T/H button on--if the grade is steep enough to let the truck speed creep above of the speed set window (presumably +/- 2 MPH).
As for the downshift mode with T/H engaged, my unit doesn't operate 'reliably' when vehicle speed is around 35 MPH or under. At higher speeds, it will kick down with successive taps of the brake pedal.
One thing you might want to check is that your brake light switch is adjusted correctly. I'm pretty sure there was a TSB/recall on this regarding the cruise control disengagment, and it may also affect the T/H mode as well.
As for the downshift mode with T/H engaged, my unit doesn't operate 'reliably' when vehicle speed is around 35 MPH or under. At higher speeds, it will kick down with successive taps of the brake pedal.
One thing you might want to check is that your brake light switch is adjusted correctly. I'm pretty sure there was a TSB/recall on this regarding the cruise control disengagment, and it may also affect the T/H mode as well.
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Joined: Sep 2009
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icantdrive55 has a point i belive there is a tsb on the cc issue you stated
as for the t/h mode ive yet to use mine towing the boat or atv's or sleds
but on its own in the mtn's it worked flawlessly for me no matter which speed i engaged it or activated it
it would down shift accordingly on a 18% grade as well as a 8%
as for the t/h mode ive yet to use mine towing the boat or atv's or sleds
but on its own in the mtn's it worked flawlessly for me no matter which speed i engaged it or activated it
it would down shift accordingly on a 18% grade as well as a 8%
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Joined: Aug 2009
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From: NWNJ
I have the 6 speed and 4.6L 3v engine.
When I was towing, I was crossing into WI from MN on I-90. When doing so there is a 8 or 9 % grade descending down for about 2 miles into LaCrosse.
The vehicle just kept gaining speed with the boat and I was trying to tap and later mash on the brake to make it downshift and start engine braking. The tach never moved higher nor did I sense the vehicle downshifting.
When I was towing, I was crossing into WI from MN on I-90. When doing so there is a 8 or 9 % grade descending down for about 2 miles into LaCrosse.
The vehicle just kept gaining speed with the boat and I was trying to tap and later mash on the brake to make it downshift and start engine braking. The tach never moved higher nor did I sense the vehicle downshifting.
If you recall the mph and rpm your truck was at, please post. I'm curious because you stated that the truck gained speed. When exploring how my truck's electronics control the trans, I used the cruse control at interstate speeds on hilly terrain. At 70mph (no load or tow), the trans would down shift to maintain speed and eliminate speed-creep. It worked really well. I know this might seem like thread drift, but if you could see if your cruse control works as I saw, the computer control programs might be interlinked with the tow/haul functions since the likely use the same monitoring parameters. Just a thought/reasoning process on my part.
Last edited by VigII; Nov 17, 2009 at 08:33 PM. Reason: note: when testing cruse ctrl, I was not in T/H mode.
