ABS Light On

My ABS Light came on today while driving an it stayed on the rest of the way home. I also had a noise the last couple of weeks, it sounded like a little (electric) motor running all the time, I could here it in the cab while driving, it wasn't all the time but maybe 60 % of the time, could this be related ?

Bert

http://tinypic.com/ei2g51

pull the ABS fuse and see if this motor runs...

this abs could be the wheel sensor in the front is defective/wiring/front wheel bearing etc...

Are you sure that it is a motor noise or a bearing noise?

Are you sure that it is a motor noise or a bearing noise?

It sounds like the humming of a little electric motor, it comes and goes.

Bert

Drive down an open road and weave back and forth at about 40mph (dont crash). If the pitch of the noise changes then it is a w/b.

Drive down an open road and weave back and forth at about 40mph (dont crash). If the pitch of the noise changes then it is a w/b.

It's not a wheel bearing, I know what that sounds like and I just replaced one. Maybe I wasn't clear, I can hear the sound even when standing still with the engine running.

Bert

On my '99 it was the ABS pump. It's under the truck beneath the driver's seat. Mine was fixed under warranty. I've read it's the electronic controller inside the unit that's actually bad.

It's not a wheel bearing, I know what that sounds like and I just replaced one. Maybe I wasn't clear, I can hear the sound even when standing still with the engine running.

Bert

pull fuses until it stops then you'll know what it is ...probably is ABS..

Also, the ABS light is funky. It's not always on just most of the time and it might be off and then when hitting a bump in the road it will come on and go right off again. Any thoughts ?

Bert

http://tinypic.com/ei2g51

because of the abs light goes on/off it is usually a wire not secured and chaffing on something...brake rotor etc...

I did some more googling and found out that's most probarly it's the EBCM that sits on top of the ABS pump, seems that I can have it rebuild for around $100.

Bert

Your EBCM relay is latching on and running the ABS pump...I had to fix my EBCM and ABS motor twice in my 2000. Here is the place to go to for ABS needs:
http://www.modulemaster.com/en/index.php
They saved me thousands of dollars over what the dealer wanted.
You can pull the ABS fuse and the pump will stop running...if you don't do that it will toast itself...the brakes work just fine but you won't have ABS and the ABS light will stay on.
If you do it yourself get the stainless steel bolts for the EBCM....but remember...you need to use the goop that comes with the bolts or they will seize in the aluminum pump housing. The guy that was helping me didn't use the goop and the EBCM malfunctioned and had to go back...on taking the bolts back out one broke and I had to get a new pump unit. The second repair even though the EBCM was under warranty cost more then the first repair.
Sonny01

Well, I got a used ABS pump with the EBCM attached and they guaranteed me it worked, so I installed it last Sunday and guess what...it still does the same thing. So today I had it scanned and it came up with C0222, C0223, C0225, C0226 and C0227 which according to the Haynes manual is both a malfunctioning left and right front ABS sensors. Is this normal they would both fail at the same time ? I'll have to check them with the Ohm meter.

Bert

http://tinypic.com/ei2g51

first I would check the abs grounds located on the frame rail driver side under the driver door area near where the park brake cable is located..

remove wire brush and re-install..if that don't work you get a meter and measure the 480MV ac COMING OUT OF THE ABS WHEEL SENSOR. this is measured whilen the wheel hub is rotated.. if you get less than 325 MV AC this is because the sensors are pushed out...but I would think that because you have the abs light intermittently on/off when the front wheel bearings got replaced the wires did not get secured correctly and then cut into the rotor..if this is your problem this is a common issue..close , easy to get damaged..

first I would check the abs grounds located on the frame rail driver side under the driver door area near where the park brake cable is located..

remove wire brush and re-install..if that don't work you get a meter and measure the 480MV ac COMING OUT OF THE ABS WHEEL SENSOR. this is measured whilen the wheel hub is rotated.. if you get less than 325 MV AC this is because the sensors are pushed out...but I would think that because you have the abs light intermittently on/off when the front wheel bearings got replaced the wires did not get secured correctly and then cut into the rotor..if this is your problem this is a common issue..close , easy to get damaged..

What exactly do you mean by "ABS Grounds" ?

Bert

What exactly do you mean by "ABS Grounds" ?

Bert


this would be the return path of current flow from the device consuming power...your vehicle has many ground points..the one I described is a common ABS failure ground ,,,,as well as the fuel pump ground point located by the fuel tank.

did you look at where this is as I described ?

this would be the return path of current flow from the device consuming power...your vehicle has many ground points..the one I described is a common ABS failure ground ,,,,as well as the fuel pump ground point located by the fuel tank.

did you look at where this is as I described ?

No, not yet. I will have lots of time this Saturday to try to fix it once and for all !

Bert

Finally had some time to look at it some more, the wires from the sensors to the wiring harness are fine, no damage/cuts or anything. Turned out that my digital voltmeter stopped working so I couldn't measure. One weird thing is that the ABS pump runs all the time even when I pull the ABS fuse it keeps running, so I went underneath and disconnected the electrical connectors on the pump and guess what...it still runs ???

Bert