Williston Posted March 15, 2008 Report Share Posted March 15, 2008 Rolling back on hills: I see that this is now an item listed on the NHTSA web site for the Edge. Can anyone (maybe from Ford) explain why they do this? I didn't really want to put this in the "3 things I hate" string. It doesn't make me hate the vehicle, but it's hard to get used to. Except for VERY steep inclines, I have never had a car that does this. It's mentioned here and there as being normal while others say it's a problem and now the NHTSA is looking into it. Comments anyone? Quote Link to comment Share on other sites More sharing options...
akirby Posted March 15, 2008 Report Share Posted March 15, 2008 Rolling back on hills: I see that this is now an item listed on the NHTSA web site for the Edge. Can anyone (maybe from Ford) explain why they do this? I didn't really want to put this in the "3 things I hate" string. It doesn't make me hate the vehicle, but it's hard to get used to. Except for VERY steep inclines, I have never had a car that does this. It's mentioned here and there as being normal while others say it's a problem and now the NHTSA is looking into it. Comments anyone? Hard to say what's "normal" anymore, but this is definitely working as designed. The torque converter stall speed was designed for fuel economy. When the engine is idling, there isn't enough torque applied to the converter to overcome the gravitational force of the hill, so it rolls back. The computer can't control the torque converter stall speed. It can only force it to lockup and if it did that while sitting still the engine would die. I guess it's possible to make other changes in the transmission controls but the only software remedy I can see is to increase the idle RPM. It's not a safety issue (I assume the NHTSA item is just a user reported problem - doesn't mean the NHTSA will take action). It's not nearly as bad as driving a car with a manual tranny, and people manage to drive those on hills with no problems. It's definitely a PITA, but not serious and not a safety issue. Quote Link to comment Share on other sites More sharing options...
Williston Posted March 15, 2008 Author Report Share Posted March 15, 2008 Hard to say what's "normal" anymore, but this is definitely working as designed. The torque converter stall speed was designed for fuel economy. When the engine is idling, there isn't enough torque applied to the converter to overcome the gravitational force of the hill, so it rolls back. The computer can't control the torque converter stall speed. It can only force it to lockup and if it did that while sitting still the engine would die. I guess it's possible to make other changes in the transmission controls but the only software remedy I can see is to increase the idle RPM. It's not a safety issue (I assume the NHTSA item is just a user reported problem - doesn't mean the NHTSA will take action). It's not nearly as bad as driving a car with a manual tranny, and people manage to drive those on hills with no problems. It's definitely a PITA, but not serious and not a safety issue. ================================================================= Thank you for the reply. I appreciate it. I just hold the brake with my left foot to compensate. Seeing it listed on the NHTSA site is interesting as I assumed it takes a certain number of reports to exceed the threshold point where it actually shows up on the site. How does the lower stall speed affect (i.e.: improve) the fuel economy? Does the economy improve while idling, cruising or coasting (or always)? I can see where it may help while at idle, (less load on tranny and engine) but does it help at other speeds as well? Quote Link to comment Share on other sites More sharing options...
akirby Posted March 17, 2008 Report Share Posted March 17, 2008 How does the lower stall speed affect (i.e.: improve) the fuel economy? Does the economy improve while idling, cruising or coasting (or always)? I can see where it may help while at idle, (less load on tranny and engine) but does it help at other speeds as well? Not exactly sure about the technical details, but I do remember a Ford engineer stating that they tried to change it to help with the rollback problem but were denied based on fuel economy impacts. I'm sure it's only a few tenths of a MPG but those things add up. Quote Link to comment Share on other sites More sharing options...
BON DIA Posted March 17, 2008 Report Share Posted March 17, 2008 (edited) It's one of the things I mention to those who drive our Edge. It's most notable on a hill when put into park & brake released. The beast rolls downhill more than any car I've ever driven, maybe a couple of inches more...be forewarned not to park too close to anything below you. Edited March 17, 2008 by BON DIA Quote Link to comment Share on other sites More sharing options...
akirby Posted March 17, 2008 Report Share Posted March 17, 2008 It's one of the things I mention to those who drive our Edge. It's most notable on a hill when put into park & brake released. The beast rolls downhill more than any car I've ever driven & will smack anything you parked too close too. That's not the same thing. We're talking about having the car in gear on an incline and having it roll back if you lift off the brake whereas some vehicles do not roll back. Sounds like you're talking about the vehicle moving after putting it in park. That's why they make a parking brake. Quote Link to comment Share on other sites More sharing options...
solas989 Posted March 17, 2008 Report Share Posted March 17, 2008 I have not noticed this phenomena much - I guess since I drive a manual, it is not an issue for me. Plus my wife has not made any comments on it either - and we have some steep grades around here (10-20% per posted signs). Will rolling back harm the transmission? Just my addition Solas Quote Link to comment Share on other sites More sharing options...
akirby Posted March 17, 2008 Report Share Posted March 17, 2008 Will rolling back harm the transmission? No - all cars do it, but some do it more easily than others. Quote Link to comment Share on other sites More sharing options...
PrinzII Posted March 17, 2008 Report Share Posted March 17, 2008 Mine did the rollback thing regardless of incline before I got the PCM flashed. Now, it won't roll back. Quote Link to comment Share on other sites More sharing options...
Always_smile1st Posted March 28, 2008 Report Share Posted March 28, 2008 Rolling back on hills: I see that this is now an item listed on the NHTSA web site for the Edge. Can anyone (maybe from Ford) explain why they do this? I didn't really want to put this in the "3 things I hate" string. It doesn't make me hate the vehicle, but it's hard to get used to. Except for VERY steep inclines, I have never had a car that does this. It's mentioned here and there as being normal while others say it's a problem and now the NHTSA is looking into it. Comments anyone? I have a 2007 Sel Edge FWD that also rolls back. When I ask the dealership about it they tell me it's normal. I don’t believe that. My 2003 accord never rolled back. The edge will roll back when I just park it in the garage and on a hill. The last thing I need is to role back into someone. This does not sound normal to me. I’m scared one day after parking the edge in my garage when I wake up the next morning the car will be in the middle of the street. Now when I go to the dealership I want it all in writing your not going to tell me it just normal. Quote Link to comment Share on other sites More sharing options...
carbonedge+ Posted March 28, 2008 Report Share Posted March 28, 2008 I have a 2007 Sel Edge FWD that also rolls back. When I ask the dealership about it they tell me it's normal. I don’t believe that. My 2003 accord never rolled back. The edge will roll back when I just park it in the garage and on a hill. The last thing I need is to role back into someone. This does not sound normal to me. I’m scared one day after parking the edge in my garage when I wake up the next morning the car will be in the middle of the street. Now when I go to the dealership I want it all in writing your not going to tell me it just normal. Might I suggest placing your Edge in Park and setting the parking brake to ensure your Edge remains in your garage... Quote Link to comment Share on other sites More sharing options...
Always_smile1st Posted March 28, 2008 Report Share Posted March 28, 2008 Might I suggest placing your Edge in Park and setting the parking brake to ensure your Edge remains in your garage... That's what I do. The problem is I should not have to. I'm glad your edge does not do that. Quote Link to comment Share on other sites More sharing options...
akirby Posted March 28, 2008 Report Share Posted March 28, 2008 That's what I do. The problem is I should not have to. I'm glad your edge does not do that. If it rolls back more than a foot or so when it's in Park then that's not normal. Rolling back when you're on a hill in Drive is perfectly normal and all automatic equipped vehicles will do that at some point. It's just that some cars do it more easily than others. The reason you can put an automatic in Drive and hold it with the brake is that there is no mechanical connection between the engine and the transmission. It uses fluid driven by a fan which in turn drives another fan that transfers torque to the tranmission. In other words, it's designed to slip when idling. In this case the torque converter is designed to slip more easily than others so it will roll back on an incline. It's normal. And you should always.....always......did I mention always?.........use the parking brake if you are parking on any type of incline. You don't want to use the transmission parking pawl to hold the vehicle. Quote Link to comment Share on other sites More sharing options...
bri719 Posted March 28, 2008 Report Share Posted March 28, 2008 Hard to say what's "normal" anymore, but this is definitely working as designed. The torque converter stall speed was designed for fuel economy. When the engine is idling, there isn't enough torque applied to the converter to overcome the gravitational force of the hill, so it rolls back. The computer can't control the torque converter stall speed. It can only force it to lockup and if it did that while sitting still the engine would die. I guess it's possible to make other changes in the transmission controls but the only software remedy I can see is to increase the idle RPM. It's not a safety issue (I assume the NHTSA item is just a user reported problem - doesn't mean the NHTSA will take action). It's not nearly as bad as driving a car with a manual tranny, and people manage to drive those on hills with no problems. It's definitely a PITA, but not serious and not a safety issue. man that is a great answer... you nailed it. are you an engineer by chance? :shades: I have driven a 5-speed manual my entire life, so to me it will probably be "who cares" and something I'd just barely notice. I know a lot of other people, it might come as a great shock but I've driven automatics which have a slight tendency to roll back on a hill also (I grew up and lived in a very hilly area most of my life). no biggie by the way, I believe based on your info and my own knowledge, this is what determines I'm at a red light or in stop-and-go traffic I don't have to pound the brake constantly or worry about not keeping enough pressure on it and having the car 'take off' on me while idling. because THAT is a real pet peeve of mine. I really hate cars that have that tendency at all... whcih I'm sure helps contribute to the gas mileage problem you're talking about. Quote Link to comment Share on other sites More sharing options...
bri719 Posted March 28, 2008 Report Share Posted March 28, 2008 Mine did the rollback thing regardless of incline before I got the PCM flashed. Now, it won't roll back. flashed? under warranty by dealer or was this an aftermarket mod? to all the people saying their Edge rolls back in park, more than just a little bit, then yeah I'd definitely take it to get looked at or research further. sounds like all Edges are not reporting this exact problem, but some are rolling back (or forward, I suppose) a significant distance in "P". as mentioned already the Drive thing on a hill is quite normal. at any rate, people should always set their parking brake when the car is on any kind of slope. I can't believe how many people I've met don't even know where the parking brake is in their car. or what it's for! they're like "oh that? yeah I don't know what that is. I've never used it before". amazing Quote Link to comment Share on other sites More sharing options...
PrinzII Posted March 29, 2008 Report Share Posted March 29, 2008 flashed? under warranty by dealer or was this an aftermarket mod? This was done under warranty by the dealer. Quote Link to comment Share on other sites More sharing options...
Blue Oval Posted April 4, 2008 Report Share Posted April 4, 2008 Just had my 08 Limited reflashed today for the rollback issue. I gave the service dept. the TSB # and they did it for me. They also replaced the headliner which had a 1/2" tear when I picked up the car two weeks ago. They said it was a pain in the ass to replace because the wires were not attached to the metal roof with clips as in most other cars, rather the wires were glued to the headliner. They had to carefully cut away all the glue and then use a glue gun to reapply the wires to the new liner. Glad I didn't have to do it! The rollback has seemed to go away so it seems to have worked. Any of you that are experiencing this symptom should have your dealer be aware of the TSB.08-05-12 Oval Quote Link to comment Share on other sites More sharing options...
Rockfish Posted April 5, 2008 Report Share Posted April 5, 2008 Not exactly sure about the technical details, but I do remember a Ford engineer stating that they tried to change it to help with the rollback problem but were denied based on fuel economy impacts. I'm sure it's only a few tenths of a MPG but those things add up. Akirby, do you know if the TSB.08-05-12 has a downside of decreasing the MPG since the fix to the rollback problem was previously denied based on fuel economy impacts Quote Link to comment Share on other sites More sharing options...
akirby Posted April 6, 2008 Report Share Posted April 6, 2008 Akirby,do you know if the TSB.08-05-12 has a downside of decreasing the MPG since the fix to the rollback problem was previously denied based on fuel economy impacts Nope - no idea. But the original change was based on using a different torque converter with a different stall speed - that's the one that was denied based on fuel economy. They're obviously not swapping out torque converters here. If they're only changing the way the car behaves at idle by increasing the idle rpm or changing the computer controls on the transmission then that probably wouldn't have a noticeable effect on fuel economy. Quote Link to comment Share on other sites More sharing options...
Blue Oval Posted April 6, 2008 Report Share Posted April 6, 2008 Nope - no idea. But the original change was based on using a different torque converter with a different stall speed - that's the one that was denied based on fuel economy. They're obviously not swapping out torque converters here. If they're only changing the way the car behaves at idle by increasing the idle rpm or changing the computer controls on the transmission then that probably wouldn't have a noticeable effect on fuel economy.Well answered akirby. They did not swap out the torque converter, only did a reflash on the tranny. Quote Link to comment Share on other sites More sharing options...
Rockfish Posted April 7, 2008 Report Share Posted April 7, 2008 Well answered akirby. They did not swap out the torque converter, only did a reflash on the tranny. Blue, PrinzII and anyone else who had the TSB applied to prevent rollback. Has your hot idle rpm changed? If it has not, then I would assume MPG may not change but I am far from understanding what is actually changed when the TSB is applied. Quote Link to comment Share on other sites More sharing options...
Blue Oval Posted April 7, 2008 Report Share Posted April 7, 2008 Blue, PrinzII and anyone else who had the TSB applied to prevent rollback. Has your hot idle rpm changed? If it has not, then I would assume MPG may not change but I am far from understanding what is actually changed when the TSB is applied. Please explain what "hot' idle is. Do you mean after the car has warmed up and the idle has kicked down? I will check on this and report back. Quote Link to comment Share on other sites More sharing options...
Rockfish Posted April 7, 2008 Report Share Posted April 7, 2008 Please explain what "hot' idle is. Do you mean after the car has warmed up and the idle has kicked down? I will check on this and report back. Yes, that is correct. Let's compare the idle (car stopped with foot on brake in order to mimic the stopped and rolling back condition that the TSB corrects) RPMs in drive at normal operating temperature verses the cold idle which is typically higher when you start up in the morning. If the RPMs are the same then the TSB must change some other transmission setting to prevent rollback. These settings and how they operate are wwwwwwway beyond my knowledge of the transmission. I would just like to know if my MPG will change if I ask for the TSB to be applied to my one week old Edge since it also has the rollback condition. Quote Link to comment Share on other sites More sharing options...
Blue Oval Posted April 9, 2008 Report Share Posted April 9, 2008 Yes, that is correct. Let's compare the idle (car stopped with foot on brake in order to mimic the stopped and rolling back condition that the TSB corrects) RPMs in drive at normal operating temperature verses the cold idle which is typically higher when you start up in the morning.If the RPMs are the same then the TSB must change some other transmission setting to prevent rollback. These settings and how they operate are wwwwwwway beyond my knowledge of the transmission. I would just like to know if my MPG will change if I ask for the TSB to be applied to my one week old Edge since it also has the rollback condition. At cold idle I'm around 800-1000 RPM's-----When the Edge is warm whether my foot is on the brake in Drive or idling, I'm at 600 RPM's. Oval Quote Link to comment Share on other sites More sharing options...
Rockfish Posted April 10, 2008 Report Share Posted April 10, 2008 At cold idle I'm around 800-1000 RPM's-----When the Edge is warm whether my foot is on the brake in Drive or idling, I'm at 600 RPM's. Oval Thanks for checking. Mine is also around 600 rpm in drive. Since I have the rollback problem, I will assume that the fix is not affecting the MPG at least as far as the idle speed is concerned. Quote Link to comment Share on other sites More sharing options...
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