ABS Light

[DavidS827]

My ABS light recently started to come on. It doesnt come on every time I drive and although im not sure of this, it seems to come on after driving down gravel (bumpy) roads. I have an 02 f150 5.4L with about 168k miles. Where would you start looking? I hear the rear abs sensor goes out first on these. Also…the hubs on this arent even a year old….not sure that helps either, but figured I would throw it out there because i think new sensors come with them.

Topic

[pcmdjason]

I know on the Dodge trucks they seem to be any combination of on the wheels, differential or side of the transmission.
It took me a few attempts on my 99 Dodge to get the right one replaced. But on the Dodges it is common for the speedometer to stop working as well.

Maybe the wire is loose or shorting on yours.

[dreamer2355]

I would have the ABS code scanned. Once you know the issue, then you can start your diagnosis.

If the code is for a speed sensor issue, you can check the ABS tone rings on most vehicles for corrosion. If thats the case, clean them up and see if that helps with the issue.

You can test most ABS sensors with a DVOM on the AC setting while you spin the wheel.

[EricTheCarGuy]

Quoted From dreamer2355:

I would have the ABS code scanned. Once you know the issue, then you can start your diagnosis.

If the code is for a speed sensor issue, you can check the ABS tone rings on most vehicles for corrosion. If thats the case, clean them up and see if that helps with the issue.

You can test most ABS sensors with a DVOM on the AC setting while you spin the wheel.

Yes don’t throw parts at it, scan for codes and see what you’ve got and take it from there.

[Dr. Jerryrigger]

Absolutly start with a scan tool. If that’s a pain for you to scan it you could do a visual inspection first. A sensor could have come loose or conector may be loose, but there is really no reason to replace anything untill you really know which wheel the code is coming from.

[redfury]

Agreed. Since you mention it happened on a bumpy road, there’s a chance that either there is an intermittent problem due to a broken wire or similar. The code should give you a clue as to what part of the ABS to check. Likely it’s one of the sensors at the wheel since they take the most abuse out of anything else in the system in regards to what the road throws at it.

[DavidS827]

Thanks guys. It looks like it is cheaper to buy an ABS scan tool than it is to take it somewhere and have them tell me what the code is. I’ll let you know what I find out.

[Lonestartech]

Also something to keep in mind. I’ve seen this from time to time. While traveling on a bumpy surface, like say cobblestone or gravel, it’s possible to get an intermittent ABS light and nothing be wrong with the system. Double check it by driving on regular pavement. If you can’t duplicate it then you might want to try wiggling your wiring harnesses close to your sensors and see if you get a light also. Just a suggestion. Good luck.

[DavidS827]

Does anyone know if I can go to advance or auto zone and have them use their scan tool? I know they do it for engine codes, but I’m not sure about abs codes. Thanks.

[Shaun_300]

Definitely get it scanned to see what corner you’re dealing with. Sounds like a possible wiring issue, shorting or opening when going over bumps. Like stated above you can check the hub for AC voltage with it unplugged and turning the wheel. I usually do a resistance check, all GM sensors are 1000-1100 ohms, also go from each pin to ground (IE rotor or spindle) to see if it’s internally shorted to ground.

[TejasNW]

David,

Yes, the stores’ scan tools can be used to pull all codes, breaks as well as engine codes.

[jbone]

MAybe a cracked tone ring or bad wheel sensor….Looke at ring closely for cracks and wiggle wiring to sensor. maybe sensor connection dirty

[Trcustoms719]

Your going to need to get the ABS system scanned and post the trouble codes when you get them.

[619DioFan]

Since you mention a ” grinding ” noise I would go back and check the brake components. look for anything loose or binding. do you feel any pulsation or vibration in the brake pedal when stopping ? make sure your battery and charging system are in good shape ( a failing charging system can turn this light on ) you can try resetting the light by disconnecting the negative battery cable for about a minute.

[jcc007]

Quoted From 619DioFan:

Since you mention a ” grinding ” noise I would go back and check the brake components. look for anything loose or binding. do you feel any pulsation or vibration in the brake pedal when stopping ? make sure your battery and charging system are in good shape ( a failing charging system can turn this light on ) you can try resetting the light by disconnecting the negative battery cable for about a minute.

The grinding noise only happens when the abs lights sometimes goes off. Im thinking of pulling the fuse or relay and then wait a day and put it back in and if it comes back on, Ill go to autozone or pepboys and get a scan.. I dont want to buy a ABS scanner I just bought a OBD II scanner and spent allot of that. I just need the codes.

[Matt]

Probably a dumb question, but do you feel the grinding noise through the pedal or through the steering wheel/chassis?

[Author]

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