I am working on a friends 94 Accord, the only problem it has is when you are going downhill on a bumpy road and hit the brakes, the ABS kicks in and the car starts violently shaking. It won't do it any other time. I did some research, so I ran the codes, and got an ABS code 21, which is parking brake?? I reset the computer and ran it again, this time no codes. I test drove the car, it still did the same exact thing. I tried to pull the codes again, and there were still none. I am stumped, so if anyone has an idea or a test for me, please let me know.

Thanks!

 

sounds like your abs modulator or whatever its called. im not sure but ive heard that thing is rediculously expensive. alternative is disabling abs.

 

How would I disable the ABS? How much is the modulator? Why wouldnt there be a code? Any other possibilities?


Modified by SilverLX351 at 3:22 PM 10/1/2005

 

im having the same problem now thats why i know this. majestic honda has it listed as $1150.27. i dont know if this is rebuildable someone else may be able to answer this.

all information on dissabling it can be found here: http://www.accordinglydone.com...e+abs

 

I'll give you a very brief description of how ABS works, and then give my opinion of what could be causing the problem on your vehicle. ABS uses wheel speed sensors to determine the speed that the wheels are turning, and when braking - how fast they are decelerating. When it senses a wheel about to lock up, it activates solenoids in the abs modulator to reduce the brake pressure to that wheel, and allow it to temporarily speed back up and regain traction. Now consider that you are driving downhill, over bumps and braking. As the tire hits a bump, it bounces, and may actually lose contact with the ground for a split second. If you happen to be braking at this time, the ABS will sense the rapid deceleration of the wheel that is bouncing off a bump, and activate the antilock. I think that the ABS system in your car is working just fine. Your problem sounds like it is actually worn struts/ shock absorbers. They are designed to dampen the bumps and prevent the wheels from bouncing up and losing contact with the pavement. If your shocks and struts are worn, which I suspect with the age and milage of your car, they are... you should look into replaceing them first before worrying about the ABS system.

 

Thanks for the response. The struts are new KYB GR2's. Also, the tires are brand new. I guess you would have to ride in the car. I know what it feels like when ABS kicks in, and this is way too violent. Are there any ABS components that wont throw a code if they are faulty?

Thanks again

 

There really aren't any componant that will fail and NOT trigger a code. There is a chance however that non OEM struts, and low profile tires, larger rims, could cause this problem. Keep in mind that those items weren't taken into account when the software engineers programmed the ABS system, and it may be a condition that you will have to live with. You could always just remove the ABS fuse and disable it all together. But you would have to live with an ABS light then.

 

well stock wheels and tires with upgraded shocks. its def possible though. i know for a fact my abs system is not working and i have no code though. so its def possible.

 

could also be a result of bad ball joints

 

They are stock rims and stock size tires, just new. If I disable the ABS, what are the bad effects?

Thanks

 

same as all cars without abs, you could lock the wheels up.

if you dont want to see the abs light, go to the link i posted ealier, it has a way to remedy this.