I have a 2004 Buick Regal LS with 194k. I haven’t had any major issues with it, but tonight I was driving and, randomly, the car started kind of bucking and jolting forward upon accelerating. I was almost to my location so, when I got there, I turned it off for about 10 minutes.
It started up fine, but I noticed the ”trac off” light came on (it would not turn off when I tried pushed the button…I thought it had possibly gotten pressed accidentally by someone getting out of the car).
At first the car was not doing the jolting thing, but about 5 minutes into the drive it started again. The ”check engine” and ”service vehicle soon” lights also came on. The ABS light has been on for a long time which the mechanic couldn’t figure out. I don’t know if it’s related or not. I can’t run it on the scanner until the AM, but any suggestions as to what the problem could be would be GREATLY appreciated!
The jolting you describe that your Buick is doing is caused by the transmission. It is also known as bucking or lurching.
Most likely this is caused because the traction light is on. That system works in conjunction with the ABS brakes. This would also turn on the service vehicle light.
When the computer sees a problem in the traction control it cannot make the shifting patterns as well as it would like to, so it defaults to a different pattern. Usually the shifts will be late and hard. Sometimes it will bang into each gear.
The ABS system is going to have to be diagnosed and repaired, then the codes cleared to get the car back to normal. Without knowing what codes are stored in the ABS computer, I cannot really guess what the problem is.
Common causes for this warning light are a bad front wheel speed sensor. The sensor is part of the front hub, also called the wheel bearing. 
These are common to cause the ABS and traction warnings. This in turn will cause the transmission to shift bad. If you could give us the code stored in the computer I am sure we can give you a better idea or what may be wrong with your Buick.
Just reply and we can get a better idea of what is wrong with your car.
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8 Comments on "2004 Buick Regal ABS, TRAC OFF And Engine Light"
I am having a similar problem with my abs, the lights do not turn on right away it takes a couple minuets of drive time all three lights to turn on. service vehicle soon,abs, and traction control. It seems to turn on when i turn the wheel hard either way. also when turning and braking my abs kicks in and it makes it difficult to stop. i replaced both front hubs last summer, the problem went away but now has returned maybe worse. I am about to pull my wheels and check the sensors but what are the symptoms of a bad module? or loose wire?
Oh and would that tcc selenoid issue cause what’s happening with my car?
Yes it would.
I guess it’s time to get a second opinion then! Thanks for your help.
On my 2004 Buick rendezvous the abs lite and all wheel drive lite are on . Also am hearing some kind of noise from it sounds like the rear of the car. What are the most likely problems and or solutions? Help
The ABS light and a noise are usually the sign of a bad wheel bearing. The ABS wheel speed sensors are part of each bearing. You may have a bad one. This would also cause the all wheel drive to be disabled. You need to get the ABS codes scanned from the computer to see which one is having a problem.
Thanks for your help. I hooked it up to the code scanner and the one I got was P0742. It was something to do with the torque converter and the circuit being stuck on. I took it to Sears and had them do a diagnos the problem. They looked at the code history and found one that said my transmission had overheated (likely when my water pump went out). They just told me I need a new transmission. I don’t have a good mechanic here yet that I trust so I don’t know if they are just trying to get the $3500 from me or are being honest. Also, the trac off and service vehicle lights have since turned off (ABS and service engine lights are still on). My car has done that lurching thing one time since and hasn’t done it in a few days now. Obviously, I’m only driving if necessary (this is the only vehicle I have) and haven’t taken it on the highway at all. The first guy I talked to at Sears (a friend’s close friend/mechanic) said it didn’t seem like it’d be the tranny since it does it off and on, but I guess mechanics at sears are only delegated certain tasks and he doesn’t do tranny work there. It was the tranny guy who said I needed a new one which makes me even more confused.
Normally a P0742 TCC stuck is not grounds for replacing the transmission. That is usually just the TCC solenoid in the side cover of the trans. That part is about $75 plus 4 hours labor to replace it.