I posted this in the van forum and got no response. The "search" function was not helpful. I'm hoping you guys can assist.

Both the yellow ABS and red Brake warning lights came on in my '99 E-350 with 4WABS as I was cruising down the highway on a long tow. I've gone through the manual as far as I can go, checking all the obvious, short of pulling codes.

The RABS instructions show you can pull codes by grounding a wire, but the closest B/O wire I found was on a plug in the engine compartment, passenger side. Grounding that wire did not result in the ABS warning light flashing. Further, my SuperChips 1715 did not produce any fault codes in diagnostic mode.

Does the 4WABS system require a specific code reader, or is there another wire somewhere that I need to ground to get fault codes? Any other suggestions to troubleshoot this?

Thanks.

 

Anything on this, folks? Does anyone know about the ABS systems on '99s? - Greg

 

I had the same situation on my 99 F250 last weekend. I found the bleeder screw on one front wheel was loose enough to leak when applying the brakes, and the resulting low master cylinder caused the ABS and brake light on the dash to come on.

 

Thanks, Dave, I appreciate the feedback.

Unfortunately, that doesn't seem to be my problem. The master cylinder reservoir level is good, I can find no leaks, and I've electrical-tested both the parking brake and MC switches... - Greg

 

Greg,

First step is to identify if you have RABS or 4WABS. Inspect your FRONT wheel hubs for any electrical harness for the sensors. If present, you have 4WABS. If there are none, you have RABS.

If 4WABS, you will need a "special" scan tool, ie, one that is capable of reading the supplemtal Ford systems (ANS, SRS, etc). These start at around $1000...

If RABS, the jumper is behind the right side kick panel.

There are three typical reasons for the BRAKE light to come on on either system: Fluid level/switch, parking brake/switch, or fault in the ABS control module. Also, should come on in START.

Verify the fluid level is correct. Release parking brake. Turn the ignition off, disconnect the ABS control module, turn the igntion to RUN and observe the BRAKE light. If no OFF, the ABS control module is likely at fault. If still on, a fault exists in either the fluid level or parking brake switch circuits that must be corrected first.

Also, if your vehicle is equipped with DRL, there may be additional checks to be made.

Steve

 

I have a 99 F250 SD, and I get my ABS light come on from time to time, especially if its raining.
On my truck, I noticed when i start the truck, I keep my foot on the brake pedal really hard, and the ABS light would go off. Try it, might work.
Note:
Had to pass my saftety inspection since I imported my F250 from out of Canada, the inspector didnt mind my ABS light was on, he said, "its a Ford, they always have problems, you better off with out the ABS anyways". And gave me my saftety sticker.

Good luck..

 

Steve, thanks.

Got 'em. I was originally in "RABS" mindset because I came from a '93 E-350. After failing to find the connector - and then having a light bulb go from recalling the front sensors and ABS wheel in the hubs when I did brakes last month - I finally recognized what I really have is 4WABS.

Crap, figures. Dealer item?

Thanks, Steve. I have checked and tested the fluid switch and the parking brake release switch with a VOM, both work correctly. Brake fluid is good. Both ABS and BRAKE comes on with the ignition, and both come on during START. About ~2-3 seconds after start the ABS light flickers off, I hear a click under the dash, then it comes right back on. The BRAKE light never goes off.

I do not have DRLs.

I will do your check with the control module; I'm becoming more suspect now that is the problem...odd that it happened simply driving down the highway...

Thanks again. - Greg

 

Greg,

An easier method...unplug the float switch connector...The output of the 4WABS module is routed through it (TN/LG wire).

Scanner: Dealer or a very well equipped shop. Call around.

Chief: Don't see as how that actually fixed (as in repaired) anything....

Steve

 

Steve, if you mean the float switch in the master cylinder reservoir, I've already cycled the power with that disconnected when I was doing diagnosis; no change in the lights, they stayed on.

So, sounds like an ABS module, unless I find some wiring problems somewhere. I have to dig around and find the location of that module; maybe I'll get lucky and it became disconnected while driving along (fat chance...). - GA

 

Alright, I just looked at the correct diagram (4WABS - Gas engine). Sorry, wrong info above about disconnecting the float switch.

PM me your email address, I'll pu together and send you a package of pdf files with schematics, component locators, and the diagnostic procedure.

Steve

 

Hi All, My ABS light came on a few days ago and I knew my rear brakes were low on my 2000 F150. I changed my brakes and the light stayed on. If I start the truck and hold my foot on the brake pedal the light is off. As soon as I let my foot off the brake, it goes back on. I was told I had to reset the ABS light. How do I do that? By the way my truck is a 6 cyl manual shift if that makes a difference.

 

i have a 2000 f350 psd and the abs light came on along with the speedo would quit working sometimes. come to find out, i changed the VSS sensor and everthing cleared up. but it didnt set a code that it was bad. could be goin bad and not set a code all the time. sensor costs only $30. this sensor could cause all kinds of prob. when bad

 

GregA - As i mentioned before, I had the exact same problem with my '99 E350. I changed the sensor on top of the differential and that resolved the problem. I called it the Rear Speed Sensor and it cost about $26 to replace. It was the problem.

 

Well, I was at NAPA today for other reasons and asked them about that sensor. $9 and it's a Delphi part. I figured, hey what the heck, so I bought it.

I installed it just now. Started up the truck and - no Brake or ABS lights! Makes no sense; according to all troubleshooting and diagrams I got from Steve a failure of that sensor should not turn on the Brake light (just the ABS). But, it did. It took me all of 5 minutes (took me longer to re-get the right socket - I originally picked 7/16 and it's 1/2 - than it did to replace it).

However, it revealed a bigger problem: my pinion seal is leaking. There's oil all over the underside of the van back there, and when I topped off the diff it took almost 2 whole quarts (in a 6 pint system!). This doesn't bode well for my newly-installed 4.30 LS diff; I hope everything's in OK shape back there. Now, to find someone with the right tools to replace that diff...

Thanks for the help, all. - Greg

 

im glad that worked for ya but sorry bout the leak. this site is such a life saver & real money saver as well. thank goodness for FTE!!!