Bad ABS?
#1
Bad ABS?
On the car, not me
Hi all, this may be an everything is fine situation, but I figured I would ask,
I have a 93 bonnie, and this is the first car I own with ABS.
When I first drive, after 10 feet or so, if I have my foot on the brake I get a little foot massage. I'm guessing that'* the ABS check.
This morning, I was cruzing on the highway, it had just rained and traffic started. I got on the brakes, and slid. ABS light came on, but I never felt any pulse.
Ever since I'v owned the vehicle, I've never felt the pulse unless it was within those first 10 feet.
Is everything fine or do I need to dig a little more?
Thanks
Hi all, this may be an everything is fine situation, but I figured I would ask,
I have a 93 bonnie, and this is the first car I own with ABS.
When I first drive, after 10 feet or so, if I have my foot on the brake I get a little foot massage. I'm guessing that'* the ABS check.
This morning, I was cruzing on the highway, it had just rained and traffic started. I got on the brakes, and slid. ABS light came on, but I never felt any pulse.
Ever since I'v owned the vehicle, I've never felt the pulse unless it was within those first 10 feet.
Is everything fine or do I need to dig a little more?
Thanks
#2
Sounds like a wheel sensor going. You would have to find someone that can scan that year(dealership) and find out which sensor is going. My 2000 Blazer did the same thing. Bad left front sensor.
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#3
I wouldn't play the diagnostic card just yet, because I have had my share of ABS flukes that crop up that I can readily explain.
First off, a warning. Our generation of ABS is VERY quick to trip a code, and also monitors WSS'* at all times, not just under braking.
The 'Foot Massage' condition you describe is perfectly normal in the first 10 feet. The owners manual even specifically mentions it.
Now... aside from that, you should never get any feedback until the system intervenes. At speeds under 10-15mph, I would describe the operation as a vibration, or buzz. It seems as if any lockup at low speed sends the system in to full intervention/lockdown. Anything beyond low speed, and you will get feedback based on what is happening. If one wheel starts to lock, you will get some feedback (pulsing) in the pedal. As more wheels lock up, you will get more and more feedback, until the feedback will then push the pedal back at you once all 4 wheels are locking. A nice loose and smooth dirt road can be used to demonstrate it without too much drama.
My ABS has faulted and disabled itself under the following conditions:
EBrake Slides
Mismatched tires (New ones on front, old (4/32 or so) on rear, matched pairs, this one was intermittant)
Noisy rear breaks (Dragging the ebrake, but not dragging the tire)
Bad battery (Like Freaking bad, as in the ABS Self test failed and almost killed the engine bad)
And, most interestingly, sticky brakes. My drums like to grab pretty bad when first starting out. Even more so when it is damp out. If you couple that with rain, snow, or ice on the road, you are left with a wheel that locks up at the drop of a hat. When a brake acts like that, the system is left to believe a speed sensor has gone funky, it faults, and then disables the system. I have to drag the brakes off when this happens, and then restart the car, business as usual.
My suggestion: If it is a 93 as you say, I believe you can jumper 2 terminals on the OBD port (don't recall which ones), and you can get the ABS codes flashed out. They should be in there even if the problem doesn't return. If it is the 94 in your signature, I don't know if you still have that luxury.
Or you could just keep driving it until the problem surfaces more clearly. Anything that happens once can be written off as a fluke.
Sorry for getting all long winded and preachy on this one.
First off, a warning. Our generation of ABS is VERY quick to trip a code, and also monitors WSS'* at all times, not just under braking.
The 'Foot Massage' condition you describe is perfectly normal in the first 10 feet. The owners manual even specifically mentions it.
Now... aside from that, you should never get any feedback until the system intervenes. At speeds under 10-15mph, I would describe the operation as a vibration, or buzz. It seems as if any lockup at low speed sends the system in to full intervention/lockdown. Anything beyond low speed, and you will get feedback based on what is happening. If one wheel starts to lock, you will get some feedback (pulsing) in the pedal. As more wheels lock up, you will get more and more feedback, until the feedback will then push the pedal back at you once all 4 wheels are locking. A nice loose and smooth dirt road can be used to demonstrate it without too much drama.
My ABS has faulted and disabled itself under the following conditions:
EBrake Slides
Mismatched tires (New ones on front, old (4/32 or so) on rear, matched pairs, this one was intermittant)
Noisy rear breaks (Dragging the ebrake, but not dragging the tire)
Bad battery (Like Freaking bad, as in the ABS Self test failed and almost killed the engine bad)
And, most interestingly, sticky brakes. My drums like to grab pretty bad when first starting out. Even more so when it is damp out. If you couple that with rain, snow, or ice on the road, you are left with a wheel that locks up at the drop of a hat. When a brake acts like that, the system is left to believe a speed sensor has gone funky, it faults, and then disables the system. I have to drag the brakes off when this happens, and then restart the car, business as usual.
My suggestion: If it is a 93 as you say, I believe you can jumper 2 terminals on the OBD port (don't recall which ones), and you can get the ABS codes flashed out. They should be in there even if the problem doesn't return. If it is the 94 in your signature, I don't know if you still have that luxury.
Or you could just keep driving it until the problem surfaces more clearly. Anything that happens once can be written off as a fluke.
Sorry for getting all long winded and preachy on this one.
#7
Check your wheel bearings for play the abs tone ring in on your bearing and the speed sensor reads off the abs tone ring if there is play you would throw a code this happened to me even just a dirty speed sensor can cause your issue most of the time it is speed sensor related and it'* fairly easy to test them if you have a volt meter but check your bearings first
#8
Hi all,
Been very busy so I haven't had a chance to perform everything above.
My wife did get cut off the other day and jammed on the brakes. now the ABS light is always on.
I looked at the code and only have a 12. I'm guessing the code cleared.
Been very busy so I haven't had a chance to perform everything above.
My wife did get cut off the other day and jammed on the brakes. now the ABS light is always on.
I looked at the code and only have a 12. I'm guessing the code cleared.
#10
Did you try the same way you would normally pull engine codes? I ask because the ABS must be pulled using a different method, as they are 2 separate systems. Not sure what the procedures are, assuming they can even be flashed out in the same way.