Trac Off Light...Shifting Weird

Well it happened first a few weeks ago, and then never happened again. Now it happens everytime I drive, and is getting to be quite annoying. When I'm driving my trac off light come on, and stays on. Some times it turns off, but the side effect stays. What happens is, the trac light comes on, and the tranny starts to shift a lil differently. Especially when going from 1st-2nd it kicks really really hard, and the car is slow to accelerate. When i turn the car off and then restart it, the tranny shifts fine....until the light comes on again. The light comes on sporatically, and not at any particular point. I have my car lowered, with 18s, a ps2, a monitor...some neons, etc etc etc....all this wouldnt play a part would it? Cause the repair shop said maybe the lowering messed something up traction wise....or the electronics shorted out the control box and thats why it keeps coming on. Any help would be appreciated!

I'm having the same problem with my 01 sunfire, the dealership told me it was one of the speed sensors. My warranty of course doesn't cover sensors on the transmission so one of my friends who's a mechanic said we could try switching out the output speed sensor on the transmission which is located on the case by the axle, I think it's going to cost me like $20.

If it doesn't fix the problem I was told it could be that the input sensor is bad too, which cost about the same but labor is crazy since they have to open the transmission up.

I will be replacing the output sensor in a couple of days , if it fixes the problem I will let you know. I know how annoying it is, my car is at the point where it starts doing this after just 5 minutes of driving.

I have this same problem with my 99 Alero. The first time it happened was about this time last year (Oct '03). Then it was fine for about 6 months then it did it again one day and then again about a week later for a day. Then it was fine for about 3 months before it did it again 2 days in a row. It's been fine since then until today.

As long as the Trac Off light is off, it shifts smoothly but as soon as it comes on it starts shifting hard and even seems to run a bit differently. When the light goes back off, back to smooth shifting with the occasionaly exception of the first time or two it shifts after the light goes off.. as if it's getting back in synch with how it's supposed to shift. Usually the light doesn't go off until the car has been stopped and restarted later but I think I recall a time it went off on it's own while driving/running.

I've searched the net and cannot find any info on this problem and only a couple of reports with people experiencing the same thing. If there is anyone out there with info/ideas about what's causing this problem or anyone who's had it and has had it resolved, I'd love to hear from you. I'd like to know what to expect and what it takes to fix it... both work and the cost.

Thanks

A friend of mine had a 2001 alero and his problem was as follows:

When switching from third to drive, the car would seem to slip. He always thought it was normal. However, it started getting to the point where it would slip and the service engine soon / trac off lights would blink just before and after the slipping and then go out. As long as you weren't trying to shift gears and even when shifting in the lower gears there was no problem.

The problem turned out to be a burnt engine coil. Which was causing the #3 sparkplug to misfire. So while it felt like it was a tranny problem it was actually not.

Whether this has any bearing on your problem I do not know. However, more info can't hurt.

- Matt

it could also be a bad wheel speed sensor, as anything that would cause a different reading at one wheel than the others would cause this light to come on.

it could also be a bad wheel speed sensor, as anything that would cause a different reading at one wheel than the others would cause this light to come on.


I have since replaced one wheel sensor on my car.. Which cost me about $350.
I noticed this when my ABS light and TRAC OFF/ON lights were lighting up every once and a while then they were constantly on.

I have since noticed the same thing happening when I go over railroad tracks or dips in the road. It seems to tell me my right side sensor may be going as well.

When mine went the first time other than the beeping from the warning lights I did notice a looseness in my steering once the ABS light came on.

I did however recieve a BAD sensor the first time I took my car in, we soon reliazed this and my mechanic replaced it no problem.

This is a very common issue with Aleros.

the other thing to look at is a bad hub bearing. That would cause the loose steering feel you describe.

Hey guys,
My alero has had the same type of problem, but it doesn't happen very often. It happened when I first got the car and they said it might be related to disconnecting the battery, its like the transmission is getting used to your driving again?! But what i have noticed is that if you shift between gears a lot, (i have an auto trans.) that it is more likely to do that. However, I did have a misfire on cyl. #2, but the next day, it stopped, the garage cleared the codes, and it hasn't happened since?! Does anyone think I might have a burnt-out engine coil as well?? anything will help!
thanx
-jordan
P.S. how much does it cost to replace an engine coil, and is it hard to do?

sorry, i forgot to mention the problem!! It seems to slip the gear at first, and accerlate really slow, at high rpm's, but then it will kick in, and be normal.
-jordan

I seem to be having similar problems. My transmission seems to shift way too much,due to what seems to be lose of power. If you find out for sure what your problem is please post. (I really need to take it in to the dealer) By the way if you do change ignition coils ,I would recommend changing all three at the same time. Heard this on one of the hot rod shows on tv. Also check plugs and plug wires when you change coils. I noticed two of mine had corroded tips on them. Don't know what caused that. I cleaned them and put some silicone grease on them. Guess they're ok. The problem I'm trying to solve is the knock I get on start-up. Not as noticable after warmed up.

Good luck, TomF

Tom:
Do you have the 3.4L v6? If so, that knock is probably piston slap. The 3.1's and 3.4's are notorious for it. I had this problem so bad on my 97 Malibu, and like you said, it was really loud when the engine was cold, then got quieter as it warmed up.

Jeremy

Jeremy,
I have the 3.4. It actually didn't make that noise until about 45-50k. My 4.3 chevy did the same thing also. So I'm guessing there's nothing that can be done to correct it? I guess I can live with it. Just sounds kinda cheap.

THanks, TomF

I had this problem and since had no problems. I first replaced the speed output sensor, peice of cake and solved nothing. I checked the codes P0717. The shifted hard into drive and each gear once moving. So we had it towed into a local transmission shop. It turns out these cars have a wiring harness inside the transmission (dumb). It was shorting out and causing the issue. At the same time we had them put in a new input speed sensor. After which we owed them $1,100 and the car worked fine. Until today, after I struggled with the stupid Passlock security for about 5hours. I finally had it running code free and the Traction light came on in park at idle. It caused a little fumble in the idle when it did come on. ANd it shifts as it did before. My guess is its because I forgot to plug the intake temp sensor back in after unhooking the battery. I will have to check the code, clear it and see what happens from here. Other things that can cause it to shift hard are related to the air metering devices and their wiring.

I was trying to sell the car today ofcourse...:banghead:

Heres a link to a thread I had going regarding my issues. Basically a blog but lots of info inside.
http://iowaautoforums.com/viewtopic.php?f=23&t=12155

Heres a link to a thread I had going regarding my issues. Basically a blog but lots of info inside.
http://iowaautoforums.com/viewtopic.php?f=23&t=12155

Welcome to AF.

It looks like another auto forum to me more than a blog. Are you a Moderator there?

I had this same exact problem happen last night, 01 Sunfire, 2.2L 2 door. and as of right now the car is running perfectly fine. this is what happened, my friends and i put my cool air intake on and while putting it on the sensor that goes in the air intake fell and i stepped on it. so i had no air sensor, we figured it would be okay to drive home (approx 15 miles) where i had a spare parts car on the way home i noticed that every time my car shifted it would jerk the entire car, i had to make a quick stop and when i got back in the car i noticed it was doing it every time the car shifted in any way, from park to drive, from park to reverse, from 1st to 2nd was the worst tho. so i got home and replaced the sensor, started my car and it was still doing it! so i was checking all my fluids and everything else thinking the worst, at this point it was about mid night, so i went to bed, woke up at 7 got in my car and it was still doing the same shit, about 20 mins in to my drive it started shifting right and my TRAC OFF light shut down!!! now the only problem was the check engine light, i got to school and decided after class i would bring it to Advanced Auto Parts for a free scan and find the problem. 2:30, i get in my car to bring it to AAP, start the car and the check engine light is gone too, i suppose it just needed time to reset the codes on its own. No problems since.

Long story short: IF BOTH YOUR TRAC OFF LIGHT AND CHECK ENGINE LIGHT IS ON. CHECK THE SENSOR THAT GOES IN TO YOUR INTAKE, AND MAKE SURE ALL THE WIRING IS STILL CONNECTED. then just drive it for a bit and it should be good, or get the codes reset, i heard you can do that your self by leaving the NEGATIVE side of your battery Ddisconnected for about 20 mins.

and some advice to pontiac sunfire owners with the 2.2L like my self, and ya want alot more power for a little bit of money, a cool air intake does wonders!!!

Hope this helps, have a good one.