ABS light always on...

[93_blk_blk_mtx]

My ABS light has been on for the past 8 months, and now I need to fix it. I've done some research in the SHOforum and it looks like I need to do a visual check around the sensors. First off, I do have a good amount of rust underneath my car.

My question, what would the sensors look like and what would be the best method to take off rust without destroying the sensors?

Another question:
What is involved when considering the entire ABS system; ABS computer, sensors.....?

I would like to fix the ABS light (that will not go away) correctly. Thank you once again to all.

 

[luigisho]

The sensors are attached to the knuckle. There is a dedicated hole in each one. You will see it behind the wheels. It points to a toothed ring on the half-shafts near the wheel. I don't know about cleaning the rust off but I know if you try to remove it it will break and need to be replaced. The little screws that hold them on are fragile and will break easily. There should be codes for the ABS system but I have not ever tried to retrieve them. I would bet it needs to be done at a dealership for a pretty penny. Make sure your sensors, the connections and the ring on the axles are intact.

 

[Ishodu]

Yeah check over the rings for massive rust build up and cracks. If you need to get the codes you need a reader. I got one at wall mart for 20 bucks. Its a ford code reader its meant for the ECC and ABS. The reason I got it was I had a ABS light too. This gave me the code and fixed my prob. If you do get the codes always fix the first code first then reset then drive and see if the light is gone.

 

[93_blk_blk_mtx]

What is the Walmart brand? Currently my SHO is in tip top shape and I have no codes coming from my computer, my guess is that the rust around the sensors is the culprit.

I am very interested in the ABS reader from Walmart. Could you please provide more info on the brand and model number?

Also, what did you have to do to fix the ABS light?

This is good stuff, thank you!

 

[Ishodu]

It was in the auto section. Just said ford code reader on it.
My abs light was from the rear right sensor. But your prob could be alot of different things.

 

[SHOblime]

This may be a dumb question........ does your ABS work or not? You never specified whether it functions or not, just that the light was on.....

 

[93_blk_blk_mtx]

Beside stomping on the brakes hard...how else can I check to see if's it still working? My guess is that they are....brakes never locked up...

Good question. In any case, the light still bothers the heck out of me.

 

[SHOblime]

If you have an outside garden hose or access to some wet pavement, get going a little bit (30+) and do a "brake check" ....the water should reduce the traction enough that your abs will come on at a pretty low speed if you get on that pedal, just do it in a safe area. I'm not sure there is another way to check the operation other than testing the sensor itself with a DVOM (not sure what the specs are, I could check on monday) and a visual inspection.

 

[luigisho]

I would be surprised if the abs was working. Doesn't a fault in the system deactivate it? The best way to check is to put it through the paces and see if the abs cycles. The pulsing should be noticeable.

 

[rangerj]

If the ABS light is on it does deactivate the system. If the "Check Anti-lock Brake" warning lamp (amber) is on and the regular brake warning light (red) sequences normally, that is it comes on for a few seconds when you start the car then goes out, there are a series of test that can be done to diagnose the problem. Start with checking the connections of the Hydrolic Control Unit, Electronic Control Unit, the wheel sensors, and the pedal travel switch.

Measure the ohms resistance of the wheel sensors at the sensor connection between the sensor pins. They should be 800 to 1400 ohms.
Then measure for continuity between each sensor plug pin and vehicle ground (body). If you get continuity between either pin and ground, the sensor is bad.

When you get these things done and do not find the problem get back to me and we will do more tests. rangerj

 

[rangerj]

If the ABS light is on it does deactivate the system. If the "Check Anti-lock Brake" warning lamp (amber) is on and the regular brake warning light (red) sequences normally, that is it comes on for a few seconds when you start the car then goes out, there are a series of test that can be done to diagnose the problem. Start with checking the connections of the Hydrolic Control Unit, Electronic Control Unit, the wheel sensors, and the pedal travel switch.

Measure the ohms resistance of the wheel sensors at the sensor connection between the sensor pins. They should be 800 to 1400 ohms.
Then measure for continuity between each sensor plug pin and vehicle ground (body). If you get continuity between either pin and ground, the sensor is bad.

When you get these things done and do not find the problem get back to me and we will do more tests. rangerj

 

[projectSHO89]

If the ABS light is on, the ABS system is offline. Period. No need for any tests.

Many ABS systems used on Ford of these vintage can have the ABS codes pulled very much the same way as the CEL codes are pulled.

With the ignition switch off, jumper the LTGRN/YEL wire to the TAN/RED wire of the ABS connector.

Turn the switch to RUN and count the ABS light flashes.

Codes should be output as a two-digit code.

Steve

 

[luigisho]

Good info Steve!

 

[rangerj]

Steve,

Are you referring to running the ABS ECU "self TEST"?

 

[stangeater]

Anything with an SHO that has to do with ABS is usually expensive to fix! Trust me, I've been down that road. The truth be told, the SHO abs system isn't that great anyway. I think the wheel speed sensors will cost somewhere around $120 a piece???? Can't remember off the top of my head. Good luck.