Downshifting while going up hill
#1
10-26-2006, 11:04 PM
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Downshifting while going up hill
I have a 2006 F250 V10. When going up steep hills, I press harder on the gas pedal, and the truck downshifts as I expect. However, sometimes it seems to bypass 4th and go directly to 3rd, not always what I want. But I noticed that while going up hill I can also make it downshift if I completely let my foot off the gas pedal and then press back down. This was also true of my 2000 Ford Explorer, so it must be a Ford thing. So to downshift when going up hill, I either stomp the pedal, or lift off all the way and then press back down. Is there any advantage or disadvantage to downshifting one way or the other?
#2
10-27-2006, 10:36 AM
KyleKai
The 3v V10 mated to the 5R110w can be a tad quirky some times
Remember you have a totally electronic throttle... there is no mechanical linkage
To insure safety the sender under your foot and the receiver at the throttle body have several redundant sub systems and logic. The system must always be self testing to determine if the command is real or a fault for most throttle positions that would result in a WOT (wide open throttle)
There is a noticeable delay to the driver and for all practical purposes there is inherent latency between the commands and the actions... a hell of a lot of variables are being calculated and reacted to.
The first priority of the system logic it to consider emissions impacts, second is power to load, and third is to drive-ability
These systems are no longer tied to a simple variation in engine manifold vacuum and throttle position
When you add in a 5 speed trans with a locking clutch torque converter that has parallel computer logic the entire power-train system gets extremely complicated.
I can duplicate what you are describing either empty or with a medium to heavy load.
My 2 year experience with this system is to use tow/haul mode anytime I have 1000 or more pounds on the truck or in tow. I also learned that she prefers a steady smooth foot feed of the throttle and will behave badly if I stab it real fast under some conditions..
Remember to shift up or down, the trany logic must unlock the torque converter clutch, and wait to sense that it did unlock by the differential speed of the input and out put sides.. this takes a few milliseconds to over 2 seconds before it will command the down shift out of OD or 4th gear or any gear where the Torque converter clutch was locked.
These delays are added to the PCM delay confirming that the full throttle command is not an error, several milliseconds, and then to actually command the stepper motor on the throttle body to move the plates wider open, a few more milliseconds
With all these subtle delays there may be times when the gear choice to react is going to be a harsh two gear drop and the resultant surge of power and speed
Sounds to me like your system is working correctly and I would advise you to play with it some more on your hill/mountains with some different loads and with or with out tow/haul mode turned on. While doing this find the technique of foot feed that behaves the way you expect
Once my truck was broken in I did a fair amount of max performance take off from stop accelerations to teach myself how to get the best drag race type start (lots of them thar Dodgem Ram Hemi-rhoids down here)
I found that a stabbed full throttle foot to the floor start would stumble, fall on its face and be a horrid start....the best is a steady feed to half throttle and as she is building torque then full on the floor and let the motor do it's thing
Same in the hills...like I said I know what you are describing because I can make mine do it...usually it is me pushing the foot feed too fast for all the things I described above to get done...
I also don't like this trany's tendency to not up shift until red line under certain circumstances in tow/haul mode.
With a light load on and going up an incline that I don't think is very steep...some times my trany will do the 1 to 2 shift about where in the RPM band I expect it.... but the 2 to 3 shift will only happen up above 4500 rpm when I felt that back around 3600 we were accelerating just fine to pop up to 3rd gear....
It doesn't do this all the time and I have a hard time duplicating it so eventually I chalked it up to a confused computer
The 3v V10 mated to the 5R110w can be a tad quirky some times
Remember you have a totally electronic throttle... there is no mechanical linkage
To insure safety the sender under your foot and the receiver at the throttle body have several redundant sub systems and logic. The system must always be self testing to determine if the command is real or a fault for most throttle positions that would result in a WOT (wide open throttle)
There is a noticeable delay to the driver and for all practical purposes there is inherent latency between the commands and the actions... a hell of a lot of variables are being calculated and reacted to.
The first priority of the system logic it to consider emissions impacts, second is power to load, and third is to drive-ability
These systems are no longer tied to a simple variation in engine manifold vacuum and throttle position
When you add in a 5 speed trans with a locking clutch torque converter that has parallel computer logic the entire power-train system gets extremely complicated.
I can duplicate what you are describing either empty or with a medium to heavy load.
My 2 year experience with this system is to use tow/haul mode anytime I have 1000 or more pounds on the truck or in tow. I also learned that she prefers a steady smooth foot feed of the throttle and will behave badly if I stab it real fast under some conditions..
Remember to shift up or down, the trany logic must unlock the torque converter clutch, and wait to sense that it did unlock by the differential speed of the input and out put sides.. this takes a few milliseconds to over 2 seconds before it will command the down shift out of OD or 4th gear or any gear where the Torque converter clutch was locked.
These delays are added to the PCM delay confirming that the full throttle command is not an error, several milliseconds, and then to actually command the stepper motor on the throttle body to move the plates wider open, a few more milliseconds
With all these subtle delays there may be times when the gear choice to react is going to be a harsh two gear drop and the resultant surge of power and speed
Sounds to me like your system is working correctly and I would advise you to play with it some more on your hill/mountains with some different loads and with or with out tow/haul mode turned on. While doing this find the technique of foot feed that behaves the way you expect
Once my truck was broken in I did a fair amount of max performance take off from stop accelerations to teach myself how to get the best drag race type start (lots of them thar Dodgem Ram Hemi-rhoids down here)
I found that a stabbed full throttle foot to the floor start would stumble, fall on its face and be a horrid start....the best is a steady feed to half throttle and as she is building torque then full on the floor and let the motor do it's thing
Same in the hills...like I said I know what you are describing because I can make mine do it...usually it is me pushing the foot feed too fast for all the things I described above to get done...
I also don't like this trany's tendency to not up shift until red line under certain circumstances in tow/haul mode.
With a light load on and going up an incline that I don't think is very steep...some times my trany will do the 1 to 2 shift about where in the RPM band I expect it.... but the 2 to 3 shift will only happen up above 4500 rpm when I felt that back around 3600 we were accelerating just fine to pop up to 3rd gear....
It doesn't do this all the time and I have a hard time duplicating it so eventually I chalked it up to a confused computer
#3
10-27-2006, 12:14 PM
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Thanks for the detailed reply. I have one more question. You stated "My 2 year experience with this system is to use tow/haul mode anytime I have 1000 or more pounds on the truck or in tow." I almost always haul a camper that weighs close to 2,000 pounds, and when I use tow/haul mode, I don't necessarily get better performance, just a nosier engine. In the F250 manual, it states to use tow/haul mode when hauling a heavy load. But what is "heavy"? 1,000 pounds? 5,000 pounds? But I don't want to strain the engine or transmission either. My question is, when hauling a 2,000 pound load, will it harm the engine to not use haul/tow mode? Or it it advisable to use it and try to ignore the high-rev noise (and presumably decreased mileage)? Thanks!
#4
10-27-2006, 01:07 PM
I am starting to think you need to re-teach your transmission
This is done by disconnecting the battery negative cable and let it sit for more then ten minuets... I leave it off over night
This forces three of the four computers to re-boot at next start and two of them to re-learn
The four computers are the Anti lock Brakes (ABS), Powertrain Control Module (PCM), Electronic Injector Module, and the Transmission Control Module no acronyms I have ever seen.
The Powertrain and trany computers re-learn your weight vs. terrain, stop and go habits, and change the default or "base" program in subtle ways to maximize driveability and emissions processes. These changes can vary from unnoticeable to very dramatic
I use my truck 80% empty commuting 32mile round trip mixed city highway every day....several times a year I load max weight for family trips and hunting -fishing excursions.... occasionally I will load the bed to the gills from a Lowes/Homedepot "wife project" like pallets of lumber, concrete etc.. sometimes these loads are significantly heavy in the 4 to 5 thousand pound range.
On the occasions when I know in advance I am going to do the heavy work I re-teach the trany while in tow/haul mode... the rest of the time I reset and teach it in normal "D" position with tow/haul defaulted to off.
Teaching normally is as simple as driving it normally on a 30 or more minute trek that includes 3 to 5 full stops like at lights or signs, and after the stop you are back up to 30 mph or higher... all this after the motor is up to full operating temp.
In Tow/haul mode it is the same driving requirements but with a load in the bed or a trailer in tow
If you drive the route aggressively it has a different effect on the shift patterns then if you are very passive and easy on acceleration
You can't teach both...and to tell the truth for the average person the base "D" normal empty teaching is good enough and the default tow/haul mode acts properly this way. I do the teaching in tow/haul because I like the behavior better on my longer 2400mile + excursions for a few weeks...no I do not think it gets any better fuel effeciency... just seems to shift better and more to my expectations.
I did not spend much time "experimenting" with this 05 5R110w but did extensively test re-teaching under differing driving conditions with my 2001 2v V10 and 4R100...
Back to your question.... I think your camper at 2000 pounds can be considered heavy.... but it is light enough that you can probably safely use either mode as you see fit... the biggest benefit to the tow/haul mode is the down hill deceleration logic.... in normal mode the locking clutch in the torque converter acts normally and this means un locked and freewheeling under most deceleration times like coasting to a stop with the throttle closed
In tow haul mode when throttle is closed and coasting the torque converter will stay locked longer providing engine compression braking effect and if you lightly tap the brake it will unlock, command a down shift and re-lock giving back the compression braking ...
I think the tow/haul logic is a little screwy and not very intuitive. You have to get on a steep down hill grade that you are familiar with and is a good safe road and play with it... (no wife here cus this is a jerky uncomfortable bit of training...for you)
Basically you need to see how the tow/haul mode adds in this compression braking and downshifting before you find your self way too fast on a 38% downgrade with 270 degree switchbacks needing the motor to help keep from smoking the brake pads and rotors!
This is done by disconnecting the battery negative cable and let it sit for more then ten minuets... I leave it off over night
This forces three of the four computers to re-boot at next start and two of them to re-learn
The four computers are the Anti lock Brakes (ABS), Powertrain Control Module (PCM), Electronic Injector Module, and the Transmission Control Module no acronyms I have ever seen.
The Powertrain and trany computers re-learn your weight vs. terrain, stop and go habits, and change the default or "base" program in subtle ways to maximize driveability and emissions processes. These changes can vary from unnoticeable to very dramatic
I use my truck 80% empty commuting 32mile round trip mixed city highway every day....several times a year I load max weight for family trips and hunting -fishing excursions.... occasionally I will load the bed to the gills from a Lowes/Homedepot "wife project" like pallets of lumber, concrete etc.. sometimes these loads are significantly heavy in the 4 to 5 thousand pound range.
On the occasions when I know in advance I am going to do the heavy work I re-teach the trany while in tow/haul mode... the rest of the time I reset and teach it in normal "D" position with tow/haul defaulted to off.
Teaching normally is as simple as driving it normally on a 30 or more minute trek that includes 3 to 5 full stops like at lights or signs, and after the stop you are back up to 30 mph or higher... all this after the motor is up to full operating temp.
In Tow/haul mode it is the same driving requirements but with a load in the bed or a trailer in tow
If you drive the route aggressively it has a different effect on the shift patterns then if you are very passive and easy on acceleration
You can't teach both...and to tell the truth for the average person the base "D" normal empty teaching is good enough and the default tow/haul mode acts properly this way. I do the teaching in tow/haul because I like the behavior better on my longer 2400mile + excursions for a few weeks...no I do not think it gets any better fuel effeciency... just seems to shift better and more to my expectations.
I did not spend much time "experimenting" with this 05 5R110w but did extensively test re-teaching under differing driving conditions with my 2001 2v V10 and 4R100...
Back to your question.... I think your camper at 2000 pounds can be considered heavy.... but it is light enough that you can probably safely use either mode as you see fit... the biggest benefit to the tow/haul mode is the down hill deceleration logic.... in normal mode the locking clutch in the torque converter acts normally and this means un locked and freewheeling under most deceleration times like coasting to a stop with the throttle closed
In tow haul mode when throttle is closed and coasting the torque converter will stay locked longer providing engine compression braking effect and if you lightly tap the brake it will unlock, command a down shift and re-lock giving back the compression braking ...
I think the tow/haul logic is a little screwy and not very intuitive. You have to get on a steep down hill grade that you are familiar with and is a good safe road and play with it... (no wife here cus this is a jerky uncomfortable bit of training...for you)
Basically you need to see how the tow/haul mode adds in this compression braking and downshifting before you find your self way too fast on a 38% downgrade with 270 degree switchbacks needing the motor to help keep from smoking the brake pads and rotors!
#6
10-27-2006, 02:17 PM
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engine compression braking in OD??
so if I can jump in here with a question Fredvon4.... is this normal for the tranny-
Driving at 60mph (or thereabouts..) on Cruise, NOT in Tow/Haul, in OD, when I come to a downhill section that's steep enough to increase my speed about 6-8 mph, the transmission downshifts on it's own to give me engine braking, and the revs of course go way up (mid 3000's).... all at a time when I would prefer it just coast to the bottom in the gear it's in...
Driving at 60mph (or thereabouts..) on Cruise, NOT in Tow/Haul, in OD, when I come to a downhill section that's steep enough to increase my speed about 6-8 mph, the transmission downshifts on it's own to give me engine braking, and the revs of course go way up (mid 3000's).... all at a time when I would prefer it just coast to the bottom in the gear it's in...
#7
10-27-2006, 02:37 PM
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#8
10-28-2006, 06:30 AM
Majic31
Not sure how to answer with any authority.... to me it does not sound "normal" for tow / haul mode off and a down shift like you describe...
To tell the truth, Ford has been known to do subtle changes and it is impossible to know how the computer logic is changed year to year....
My understanding of the 5R110w and the normal vs tow.haul mode is as I described above in earlier post...But perhaps the logic has been upgraded to use more compression braking in both modes... I can see from a product liability and consumer demand point of view where they may have done this.
If you can duplicate the behavior more then 80% of the time it is probably normal and something you should just be aware of and expect... on the other hand if it only does this occasionally and usually startles you to the point of reacting to the trucks behavior then I would suggest a simple reset and re-training to see if it is just screwy logic....
90% of all the 5R110 owners won't benefit from this but... I have decided for my 05 first year (V10 w/5R110w) version to re-train every 90 days when I do the oil change...I know this is ****, but I have one that has a great power PCM code and do NOT want A Ford re-flash to newer code... but my trany logic sometimes acted real screwy the first year, and did things I did NOT expect...seem to me once I started the re-training 4 times a year that this last year she has always been consistent in shift patterns...
Not sure how to answer with any authority.... to me it does not sound "normal" for tow / haul mode off and a down shift like you describe...
To tell the truth, Ford has been known to do subtle changes and it is impossible to know how the computer logic is changed year to year....
My understanding of the 5R110w and the normal vs tow.haul mode is as I described above in earlier post...But perhaps the logic has been upgraded to use more compression braking in both modes... I can see from a product liability and consumer demand point of view where they may have done this.
If you can duplicate the behavior more then 80% of the time it is probably normal and something you should just be aware of and expect... on the other hand if it only does this occasionally and usually startles you to the point of reacting to the trucks behavior then I would suggest a simple reset and re-training to see if it is just screwy logic....
90% of all the 5R110 owners won't benefit from this but... I have decided for my 05 first year (V10 w/5R110w) version to re-train every 90 days when I do the oil change...I know this is ****, but I have one that has a great power PCM code and do NOT want A Ford re-flash to newer code... but my trany logic sometimes acted real screwy the first year, and did things I did NOT expect...seem to me once I started the re-training 4 times a year that this last year she has always been consistent in shift patterns...
#9
10-28-2006, 06:41 AM
dallbright
Give me a little more info...what is the E-350 Château? what rpm and speed range... what is a slight down hill to you..how heavy is the rig, how many miles on her, do you know the rear gear ratio, how many tires and do you always check the pressure and have them all the same or less in front more in the rear...
how confident are you in steering axle alignment and drive axle alignment..
There are a lot of factor that can cause what you are describing... like a boat, trailer, or vehicle on the ground in tow behind it
short answer is NO that is NOT normal for this v10 and transmission... the cruise control is now a near perfect design. All the electronic throttle and 5R110w trans I have driven have had rock steady Cruise Control behavior... in fact I use CC about 80% of every driving day just because it is so predictable and does exactly what I tell it to do and then stay right there ..uphill, downhill, accelerating, or coast / decelerating with the steering wheel buttons... If it would work under 30~35mph... I do believe I could use the truck without a right foot.
Give me a little more info...what is the E-350 Château? what rpm and speed range... what is a slight down hill to you..how heavy is the rig, how many miles on her, do you know the rear gear ratio, how many tires and do you always check the pressure and have them all the same or less in front more in the rear...
how confident are you in steering axle alignment and drive axle alignment..
There are a lot of factor that can cause what you are describing... like a boat, trailer, or vehicle on the ground in tow behind it
short answer is NO that is NOT normal for this v10 and transmission... the cruise control is now a near perfect design. All the electronic throttle and 5R110w trans I have driven have had rock steady Cruise Control behavior... in fact I use CC about 80% of every driving day just because it is so predictable and does exactly what I tell it to do and then stay right there ..uphill, downhill, accelerating, or coast / decelerating with the steering wheel buttons... If it would work under 30~35mph... I do believe I could use the truck without a right foot.
#10
10-28-2006, 11:17 AM
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fredvon4
Well, I'll do my best:
E-350 7-passenger (window) van nothing but me in it, weighs what, maybe 6,000 (including Quigley 4x4)? Has 3,600 on it now so has done that since new. Window sticker from dealer says it has 3:73LS diff. let's see, 65 mph is about 2,100 rpm, maybe that's 70 mph, but close. Tires are factory LT245/75R16E's. Actually, unless I am hauling a load over 1,000 lbs or so I always keep my tires about 5-7 lbs. LESS in the rear. Right now I think they are 3-4 less than front tires and they still seem to stand a bit taller. Alignment was off just a whisker, but the mechanical side of the collision shop we just visited put the alignment on the mark. Not sure if they checked rear axle.
When driving at highway speeds of say 60-70, in cruise, imaging climbing a hill, it gradually levels off, then starts down again.
Climbing = power, levelling = less power needed, starting down hill (not steep) = even less power needed, then you reach the "equilibrium point where grade is just enough to overcome resistance and no power is needed, but no holdback is needed either----THAT'S the point where the van hiccups and bucks slightly, ever so slightly. The lightest of pressure on the accel. will take it away. A steeper downgrage will take it away.
Yes, I like using it too, but this quirk has me opting not to until I know more.
This unhooking the battery to reprogram sounds like a good idea, van had 67 miles on it as they had to transport it for me, but I don't know anything about the training drive. I haven't even looked at that second battery on the frame rail, I just know it's there and will have to be unhooked as well.
Any pointers anyone?
Thanks for the help, fredvon
E-350 7-passenger (window) van nothing but me in it, weighs what, maybe 6,000 (including Quigley 4x4)? Has 3,600 on it now so has done that since new. Window sticker from dealer says it has 3:73LS diff. let's see, 65 mph is about 2,100 rpm, maybe that's 70 mph, but close. Tires are factory LT245/75R16E's. Actually, unless I am hauling a load over 1,000 lbs or so I always keep my tires about 5-7 lbs. LESS in the rear. Right now I think they are 3-4 less than front tires and they still seem to stand a bit taller. Alignment was off just a whisker, but the mechanical side of the collision shop we just visited put the alignment on the mark. Not sure if they checked rear axle.
When driving at highway speeds of say 60-70, in cruise, imaging climbing a hill, it gradually levels off, then starts down again.
Climbing = power, levelling = less power needed, starting down hill (not steep) = even less power needed, then you reach the "equilibrium point where grade is just enough to overcome resistance and no power is needed, but no holdback is needed either----THAT'S the point where the van hiccups and bucks slightly, ever so slightly. The lightest of pressure on the accel. will take it away. A steeper downgrage will take it away.
Yes, I like using it too, but this quirk has me opting not to until I know more.
This unhooking the battery to reprogram sounds like a good idea, van had 67 miles on it as they had to transport it for me, but I don't know anything about the training drive. I haven't even looked at that second battery on the frame rail, I just know it's there and will have to be unhooked as well.
Any pointers anyone?
Thanks for the help, fredvon
#11
10-28-2006, 12:52 PM
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Fredvon4
Thanks for the input... I have about 6000mi on the truck now.. I'm due in for my (10000km) oil change to the dealer this Monday morning coming... I'm taking your advice and when I get it home, I'll reset those computers... if it prevents problems, then I can see following your example and just resetting every time it goes in for service...thanks again.
fyi - yes it does it every time IF the hill is steep enough for the truck to accelerate on its own... then after about 6mi speed increase it downshifts...
On shorter or not so steep hills it doesn't do it if it doesn't increase those 6mi.
Thanks for the input... I have about 6000mi on the truck now.. I'm due in for my (10000km) oil change to the dealer this Monday morning coming... I'm taking your advice and when I get it home, I'll reset those computers... if it prevents problems, then I can see following your example and just resetting every time it goes in for service...thanks again.
fyi - yes it does it every time IF the hill is steep enough for the truck to accelerate on its own... then after about 6mi speed increase it downshifts...
On shorter or not so steep hills it doesn't do it if it doesn't increase those 6mi.
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10-28-2006, 01:46 PM
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10-28-2006, 09:15 PM
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10-28-2006, 09:32 PM
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#15
10-29-2006, 08:20 AM
You guys with the "down hill" cruise control surge.....this is a new quirk for me, and yesterday I tried on three different hills on the way back from a funeral with my wife and I as only load on the 05 F350 ...could not make it do what you are describing
From dallbright's very good description of the long van, I don't see any set up or mechanical reason for a suspension or steering reason, and does not sound like "porpoising" either unless one of you with these vehicles suspect that the rear axle carries more load then the front axle.
If these vans are still within warranty, you might consider getting Ford to look at it...a good argument can be made about safety above simple drive-ability annoyance...
Perhaps Ford has a re-flash that has a better set of logic for the cruise control in that "hunting" zone of "feedback over shoot"... technically that is what is happening,,,
Also, the condition you are describing can be caused by the throttle plate stepper motor opening a tad too much then being commanded a tad too closed and continuing to do this until something intervenes, like a light pressure on the foot feed
In early 05 models the throttle position sensor, the stepper motor and the foot feed transducer had problems.... Ford fix them during late 04 through mid 05 and then we stopped hearing of the problems...
It is possible with the conversion vans that you all got some of the bad batch of sensors and stepper motors...so that is another area to have the Ford tech to consider
From dallbright's very good description of the long van, I don't see any set up or mechanical reason for a suspension or steering reason, and does not sound like "porpoising" either unless one of you with these vehicles suspect that the rear axle carries more load then the front axle.
If these vans are still within warranty, you might consider getting Ford to look at it...a good argument can be made about safety above simple drive-ability annoyance...
Perhaps Ford has a re-flash that has a better set of logic for the cruise control in that "hunting" zone of "feedback over shoot"... technically that is what is happening,,,
Also, the condition you are describing can be caused by the throttle plate stepper motor opening a tad too much then being commanded a tad too closed and continuing to do this until something intervenes, like a light pressure on the foot feed
In early 05 models the throttle position sensor, the stepper motor and the foot feed transducer had problems.... Ford fix them during late 04 through mid 05 and then we stopped hearing of the problems...
It is possible with the conversion vans that you all got some of the bad batch of sensors and stepper motors...so that is another area to have the Ford tech to consider