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well, Today Scoots gave me her first quirk. as I was going into town Today with a Stone Cold Engine, 'Ol Scoots Would not Shift into 4th for a Few minutes. (Tach was Reading 3 Grand at 55 MPH, when its SUPPOSED to be reading 2 Grand at 55 MPH) is there some sort of TCM Programming that Delays Shifting into 4th/TCC Lockup at a certain temperature? (Ambient Temp was 50*F)
An Aveo has four forward gears plus torque converter lockup. The torque converter works as part of the automatic transmission system. The lockup acts similar to a fifth gear or overdrive on automatic transmissions. (Techincally it's not a fifth gear but the TC lockup feels just like an upshift when it occurs.) On an Aveo, the torque converter doesn't enter lockup until about 45 MPH. When it does, it actually feels and looks like a shift: you will notice a drop in RPM to about 2000. If the engine is cold, the TC will not lockup at all until it reaches operating temperature. That is normal for most Asian cars, whether it is overdrive or TC lockup.Quote:
Originally Posted by 2010AveoLT
Now read this thread (click here).
Your car is probably still under warranty. If the engine is at full operating temperture and it's still revving too high at speeds over 45, there is something wrong. Bring it to a dealer and start the process of having them rectify it.
any if you find out what the problem is please let me know because mine's being doing that for 3 years now. Dealerships told me it was too cold.....but they didn't mention anything about driving around in second gear in the wintertime when I was buying it ? And synthetic oil doesn't help...tried that.
I have a Degree in Automotive Technology, I KNOW how an Automatic Transmission with TCC Works; and to HeavyDuty: its Staying in 3rd for me.Quote:
Originally Posted by Thymeclock
*Bump* its Still doing it, and now it does it EVERY Time on the First Startup of the day with the Outside Temp 50 Degrees F or lower. I've already blown ONE Engine in 2012 with my Plymouth (which caused me to get Scoots in the First Place) and I Don't want Another Blown Engine!
both my 04 aveo my kia rio have delayed shifts when cold. i think it the computer trying to get the trans/engine to warm up faster.
I'll accept that answer if its coming from either a GMDAT Engineer, an Aisin Engineer, or a Chevrolet Technician that's quoting from the Service Manual. other than that, I'm assuming my Transmission is trying to kill itself.Quote:
Originally Posted by jayman
So basically you're telling us you're a stubborn person who doesn't want the help he asked for. If youre going to be so stubborn then do to ask for our help. And 3000rpm at 55 is definitely 4th gear without tc lockup
I counted the Gears this morning when I went to town, and it was DEFINITELY in 3rd, and REFUSING to Shift into 4th. only after a few minutes of a Cold Engine SCREAMING at a Speed that Should only be seen when Blasting down the Interstate at 70 MPH did it shift into 4th. and I'm not being stubborn, just stating the fact that if this IS Normal Behavior, then I need to hear it from someone who either Repairs the car on a daily basis, or someone who helped design the Powertrain.Quote:
Originally Posted by Pickles
No degree in Automotive Technology here - just a low level, amature mechanic. But I've been driving for over 40 years, and never have blown an engine. Perhaps a big factor is that I've never pushed any vehicle until it comes up to temp - just very moderate rpms and speed. The link below describes how Chrysler programs their TCMs, using temp(s) as the key inputs. Seems like there must be some type of similar programming done for every make.Quote:
Originally Posted by 2010AveoLT
Perhaps you just had bad luck with your Plymouth. But OTOH, maybe you should think about your driving habits, and consider backing off a bit until the engine comes up to temp. Not intending to be rude or obnoxious here - just trying to offer some friendly JMHO advice.
Jeep Grand Cherokee Transmission Shifting Problem
Tell us what the shift points are that you are experiencing (under a moderate acceleration, stated in MPH).Quote:
Originally Posted by 2010AveoLT
Hello,
I apologize for any inconvenience this causing you. Regrading the shifting, I did consult the Owner's Manual and found a passage on page 1-15 regarding cold weather shifting. However, if you feel there is an issue, please address with a GM Dealer. They should be able to properly diagnose and repair a problem if it's occurring. If you decide to have it looked at by a service center, please let us know. Please send us a PM with the VIN#, your name, situation, concern, dealership name, current mileage, and contact information. I hope this is resolved quickly for you. Thank you.
From 1-15
Cold Weather Shifting
When operating the vehicle in severe cold conditions,
the transmission may be prevented from shifting into
D4 gear until the transmission fluid has warmed up to
it's operational temperature.
Matt,
GM Customer Assistance
okay, so it IS normal Operation, now it makes sense since its been only doing it below 40 Degrees F, and on the Very First start up of the day. it hasn't inconvienced me (car's been Completely Trouble free since the day I bought her; Knock on Wood), it only alarmed me because I've been used to a Chrysler 4 speed Auto that could potentially self-destruct if you didn't feed it the Proper Fluid. and to Thymeclock: my shift points were 1-2 at 15MPH, 2-3 at 30MPH, then 3-4 at 55MPH after about 2-3 minutes of staying in 3rd. Thank you Matt for your Prompt Reply, it shows that GM Truly DOES Care about its Customers.Quote:
Originally Posted by Chevy Customer Svc
The shift points occur (approximately) as follows: second at 15, third at 25, fourth at 35, followed by torque converter lockup at about 45 MPH, which feels like a shift (including the drop in RPM's) but it's actually the torque converter locking up. Even when it is cold it should go into fourth gear - but not TC lockup.Quote:
Originally Posted by 2010AveoLT
i know that, but in my case at 35 AND 45 MPH, it DOESN'T shift, and keeps going up to 55 MPH whilst staying in 3rd. but as Matt from GM Customer Service said (and Confirming what he said by reading my Owner's Manual a little closer) it looks like GM has Programmed into the TCM a program that Locks Out 4th Gear during Operation in Severely Cold Temperatures (like what is happening in my area right now) to speed up the ATF Warming Process.Quote:
Originally Posted by Thymeclock
It helps not to push things until the engine is at operating temp. As long as the A/T works well once it is warmed up and your transmission eventually goes into high gear and TC lockup, it's OK. No one can change that. Winter driving sucks.Quote:
Originally Posted by 2010AveoLT
But Aveos tend to take forever to reach operating temperature during cold weather. Why they do this is a whole 'nother story. :-"