Automatic Transmission Question

[joshritger]

I have a 2007 m3 hatch with the 5 speed automatic and was wondering what the normal shift points are for this car. Mine seems to shift up a bit early and does not like to down shift. If I am light on the gas, it will shift up by about 2000 rpm, if I am normal it will shift up just below 3000 rpm. I can't really say what rpm it down shifts at, more like what speeds. It seems to down shift from 5th to 4th at around 45 mph and can stay in 4th until I come to a stop. If I am rolling, or say I am in town and I am slowing down from say 50 but not stopping it doesn't like to down shift out of 4th even at say 20 mph unless I give it a decent amount of gas. I had the transmission warrantied last summer with only about 15,000 miles on it and it is a little better, but I still have the problem with it down shifting.

 

[chrissor]

the shift scheduale for the cars are based on throttle position, load, and speed. downshifting is is pretty much the same, aslong as you are in drive, you would just be coasting, if you are in manual gear select, you will have engine braking.

 

[joshritger]

Can anyone that has the 5 speed automatic tell me if their cars shifting pattern ever changes, mine seems to change about every other week, it gets kind of annoying and mazda has looked at mine and says that it is normal since the car is just adapting to my driving style. But this cycle repeats itself time and time again. Shouldn't the car learn my driving style and then not change unless my driving style changes drastically? They have updated the firmware on the tcm and then it drives good for about a week to a week and a half, then it reverts back to this ever changing behavior.

 

[Gothkid]

i have the 08.5 5speed auto, it shifts a little early for me but its nothing too annoying. the dealership is right though, it has its own adaptive ecu that will constantly change according to your driving style. mine changes a lot, but not enough to bother me, just let it do its thing, the computer takes hundreds of factors in when it decides a shift point, u can expect it to be the same every time, there are just too many constituents.

 

[joshritger]

I guess the thing that bugs me the most is that say I get the transmission controller reflashed, the car drives great for about a week to a week and a half. It shifts smoothly, it has great pickup, and it gets about 32 mpg. Then a week and a half goes by and then all of a sudden it starts shifting differently (different shift points), the shifting itself isn't as smooth, and the gas mileage goes down to like 28 mpg max. I am going to try and get it looked at again, but why would it vary so much from when it is flashed? I know there are alot of variables, but can't the car sense that it is driving worse not better as it changes?

 

[joshritger]

Well I have been putzing around with my car the past week or so and I think my car acts differently off and on. By this I mean one time it will drive normally and have normal acceleration and normal shifting, and other times it will seem to not be all there and shifts kinda different. The main symptoms are poor acceleration while driving, not down shifting when it should, and poor fuel economy. After reading what chrissor said and doing some research I am wondering if maybe my car is running rich. If not all of the fuel is burning, could there be too much fuel and could this cause my car to lack power. Would this then affect the shifting? What sensors affect how much fuel is being injected, and how much air is being used. Is this a plausible scenario? Oh and I have no mods to the car yet other than a drop in k&n filter.

 

[Gothkid]

dude......u get 28mpg? and thats poor economy????? i got 25 if i was lucky! now i get 23, because i have to run premium for the nitrous.

if u dont like the mpg do monztas timing mod and move to mid grade fuel. it will bump up your milage at least a point or two. it might also get rid of that 'bogged' down feel.

 

[joshritger]

I guess the mpg's aren't the big issue, it is the bogging down feel. When the car is running good, it has great pickup and shifts good. When it is running bad it gets worse mpg's and the shifting changes and it feels like it lacks power. I guess I just mentioned the mpg's because that seems to be a symptom. When it runs good it gets better mileage (when running bad ~27-28, when running good ~31-32). I know 28 mpg's isn't bad, but a 5 mpg difference between running good and bad seems like a lot. I thought maybe either too much gas was being dumped in, or maybe not enough air was being taken in, this would cause the gas to not detonate fully. That could cause a lack of power right?

 

[Gothkid]

have u tried taking it to the dealer while its running bad? dont turn the car off, just leave it running when its crappin on ya and grab the service advisor tell him to ride with you or have a mechanic ride with you.

it sounds like a sensor is malfunctioning. if its a frayed wire or a glitched sensor it will cause intermittent problems.

 

[joshritger]

Since I live about 45 min from the dealer I can't just take it there when the problem arises immediately. Is there a particular sensor that I should have them test? O2, Mass Air Flow, ...?

 

[joshritger]

On a side note, if I reset the ecu by disconnecting the battery and pumping the brakes, will this delete the ecu flash that the dealer did when I took it in last year, or will this just delete the accumulated data that the car has learned since then? I just recently did the throttle body ground and was wondering if I should have reset the ecu?

 

[Gothkid]

TB ground just gives u a better signal at the throttle, wont affect the ecu at all. And 'resetting' it that way will not get rid of the flash they did. its written in eeprom and cannot be erased without a proprietary tool. that reset just makes it learn the fuel maps all over again. i'd watch it for a couple weeks, dont do anything at all, just observe and record (on paper) what days, and if possible what times the car "acts abnormally." report what you find here and maybe we can decipher it. also maybe present it to your dealership.

remember, a good dealer wont turn down work, or the opportunity for it. even if it is warranty, its still money in their pocket, straight from mazda. However, mazda, and any other car manufacturer, is very picky about what they give warranty to. Its not that the dealer cant find anything, its that the dealer would get reamed out from misdiagnosing warranty work and not being able to prove the fault.

 

[joshritger]

Ok, I will try to pay attention to when and what the conditions are when she drives bad and good.


Thanks,
Josh