Overactive ASR Traction Control
Thread Starter
Instructor
Joined: Apr 2008
Posts: 171
Likes: 1
From: west chester pennsylvania
Overactive ASR Traction Control
95/6pd
I had my daily driver in for state inspection about a month ago. I knew the rear tires would not pass inspection so I had them mount/balance a real nice pair of 275/40/17 I had laying around.
Ever since I got my car back, the traction control has been super sensitive, to the point its annoying to drive with it turned on. Everytime I accelerate mildly hard in 1/2/3 gear, it kicks on [even though I know the wheels aren't even near spinning]. Also, everytime I accelerate around any sort of curve, it kicks on. I've driven this car everyday for around 2 years now, and have owned 2 other c4's and I've never had any issue like this after swapping tires or rims.
I have no CHECK ABS/ASR lights coming on. My brakes system is in good condition and the master cyl. is full.
Does anyone have any insight as to what may be the issue here?
Could a 1mm skinner wheel really throw off the ASR system that bad?I've put C5 and C6 wheels with varying tire sizes on c4's before and its never been a problem.
Original Tire Size: 285/40/17
New Tire Size: 275/40/17
I had my daily driver in for state inspection about a month ago. I knew the rear tires would not pass inspection so I had them mount/balance a real nice pair of 275/40/17 I had laying around.
Ever since I got my car back, the traction control has been super sensitive, to the point its annoying to drive with it turned on. Everytime I accelerate mildly hard in 1/2/3 gear, it kicks on [even though I know the wheels aren't even near spinning]. Also, everytime I accelerate around any sort of curve, it kicks on. I've driven this car everyday for around 2 years now, and have owned 2 other c4's and I've never had any issue like this after swapping tires or rims.
I have no CHECK ABS/ASR lights coming on. My brakes system is in good condition and the master cyl. is full.
Does anyone have any insight as to what may be the issue here?
Could a 1mm skinner wheel really throw off the ASR system that bad?I've put C5 and C6 wheels with varying tire sizes on c4's before and its never been a problem.
Original Tire Size: 285/40/17
New Tire Size: 275/40/17
Racer
Joined: May 2008
Posts: 430
Likes: 1
From: Austin Texas
I THINK I know what is happening:
The tires you mounted are smaller in diameter than the ones you removed, and more importantly, smaller than the front tires are.
That means the rear tires are turning just lightly more rpm than the front tires.
The computer uses the ABS sensors for TWO things:
1. If a tire starts to skid, its rpm becomes lower than the other tires, and the computer then knows that it is about to lock up and skid, and uses the ABS to prevent that
2. If a rear tire is turning FASTER than the front tires, the computer thinks it has lost traction, and so it reduces throttle, and lights up the "ASR active" light. THIS is what I think is causing your symptoms. Although these is a certain "tolerance" before the computer takes action, you have evidently accidentally triggered it.
Cure: Get the right size tires on the rear of the car?
Jim G
The tires you mounted are smaller in diameter than the ones you removed, and more importantly, smaller than the front tires are.
That means the rear tires are turning just lightly more rpm than the front tires.
The computer uses the ABS sensors for TWO things:
1. If a tire starts to skid, its rpm becomes lower than the other tires, and the computer then knows that it is about to lock up and skid, and uses the ABS to prevent that
2. If a rear tire is turning FASTER than the front tires, the computer thinks it has lost traction, and so it reduces throttle, and lights up the "ASR active" light. THIS is what I think is causing your symptoms. Although these is a certain "tolerance" before the computer takes action, you have evidently accidentally triggered it.
Cure: Get the right size tires on the rear of the car?
Jim G
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
I THINK I know what is happening:
The tires you mounted are smaller in diameter than the ones you removed, and more importantly, smaller than the front tires are.
That means the rear tires are turning just lightly more rpm than the front tires.
The computer uses the ABS sensors for TWO things:
1. If a tire starts to skid, its rpm becomes lower than the other tires, and the computer then knows that it is about to lock up and skid, and uses the ABS to prevent that
2. If a rear tire is turning FASTER than the front tires, the computer thinks it has lost traction, and so it reduces throttle, and lights up the "ASR active" light. THIS is what I think is causing your symptoms. Although these is a certain "tolerance" before the computer takes action, you have evidently accidentally triggered it.
Cure: Get the right size tires on the rear of the car?
Jim G
The tires you mounted are smaller in diameter than the ones you removed, and more importantly, smaller than the front tires are.
That means the rear tires are turning just lightly more rpm than the front tires.
The computer uses the ABS sensors for TWO things:
1. If a tire starts to skid, its rpm becomes lower than the other tires, and the computer then knows that it is about to lock up and skid, and uses the ABS to prevent that
2. If a rear tire is turning FASTER than the front tires, the computer thinks it has lost traction, and so it reduces throttle, and lights up the "ASR active" light. THIS is what I think is causing your symptoms. Although these is a certain "tolerance" before the computer takes action, you have evidently accidentally triggered it.
Cure: Get the right size tires on the rear of the car?
Jim G
The exact match in diameter would be a 245/45/17 up front, or you could go with a 255/40/17.
Intermediate
Joined: Jan 2012
Posts: 45
Likes: 0
From: Phoenix AZ
Just leave your ASR off. Not sure why anyone would want it on. I have a 94, and I think it's extremely disconcerting when it kicks in. It's not subtle at all, and I'd rather have the tires spin a little rather than have the ASR drop the throttle the way it does. 
