On my 1999 Expedition 4x4 5.4L the ABS dash light has come on a couple of times. I have only had the Expedition for about a month. The first time it came on I had made a U-turn. The second time I was just driving along and noticed it had come on. If I shut the truck off and then back on the light works normal. Any thoughts on what is going on and how to fix it?

 

I have a '99 with the same symptoms. I believe your brake fluid reservoir is low. Try adding some brake fluid.

Good luck

 

Unfortunately that is not the problem, I just checked all the fluids yesterday and the brake fluid was right where it should be. Too bad that would have been a simple solution.

 

Did you ever find the cause to this problem? I thought I had fixed my by adding more brake fluid, but it still comes on sometimes when I make a sharp turn.

 

No I have not found the problem, nor has it happened again. So I have not pursued it anymore.

 

Your problem is definetly this... Open up your rear diff. cover. Then disconnect the ABS Sensor, It's located on top of the diff. Your going to see metal shavings on it, clean off all the metal shavings. Then no more light blinking. You should also change the fluid and put a magnet in there so it won't happen again!!

 

I've seen my ABS light come on twice in the past month, thanks, BlownBronco, I'll check it out and let ya'll know what happens.

David
"St. Augustine: a quaint drinking village with a fishing problem"

 

[updated:LAST EDITED ON 01-13-03 AT 01:09 AM (EST)]There are Technical Bulletins on the light coming on for the Navigator. but I guess I got to go to ford/lincoln to get them.The summary's list at NHSTF(sp?) doesn't give enough detail.

My 98 navigator 2WD(Cannot find nav forum)is doing the same thing sort of.
Start engine
ABS light on then goes out as normal
Idle for ever no light
Back out of driveway
Go forward. after some distance light goes on(not related to speed) go slow (5mph)or go regular up to 30mph light comes on after about same distance (200 feet maybe)Light comes on and stays on until shut off and start over.
Fluid ok
No buzzing or unusual noises under hood. Can hear relays clicking in HU (Hydraulic Unit)of ABS when key turned on.
No brake Leaks
Pads New
Raise in air and wheels spin free (no brake pad bind against rotor)
60792 miles on odometer

Looking for HELP ! technical Shop manuals (Diagnostic MAPS) anything

 

TSB 99-13-13


FORD: 1997-99 EXPEDITION, F-150, F-250 LD
LINCOLN: 1998-99 NAVIGATOR


This TSB article is being republished in its entirety to state coverage for 4X2 vehicles only and revise Figure 1 .

ISSUE:
Increased brake pedal effort and/or false Anti-lock Braking System (ABS) cycling at low speeds, or ABS lamp illumination may occur on some vehicles. This may be caused by an incorrectly installed front wheel speed sensor, low vacuum in the brake booster, or a chipped or broken tooth on the tone ring resulting in reduced output to the ABS Electronic Control Unit (ECU).

ACTION:
Be sure the front wheel speed sensor is properly installed and the wires are properly routed. Refer to the following Service Procedure for details.

SERVICE PROCEDURE
Retrieve and record any ABS diagnostic trouble codes and follow procedures detailed in the appropriate Service or Workshop Manual.
Inspect both front sensor wires for tension due to improper routing ( Figure 1 and Figure 2 ). Make sure that the white clip, attached to sensor cable, is properly located on protrusion on the upper control arm ( Figure 1 ). Replace the sensor assembly as needed.
Carefully inspect the sensor wire at the sensor head. Look for any cracking or distress. Replace the sensor assembly as needed.
Inspect both front sensor bodies for improper seating to the spindle housing. Inspect the tone ring for dents, flat spots, chips or other irregularities. The sensor bracket flange should be completely flush to the spindle housing ( Figure 3 ). If any gap is present, then replace the sensor assembly with a new front wheel speed sensor.
If sensor replacement is required, all surfaces including the hole where the sensor body is inserted must be free of rust build-up. Use a wire brush or die grinder to thoroughly clean all surfaces where the sensor seats.

 

[updated:LAST EDITED ON 01-13-03 AT 02:15 AM (EST)]Thanks I will check these mechanical sensor and vacuum areas.

Are there any voltages or electrical diagnostics that can be run ? I do not have a scan tool to determine codes.

One thing....Did the following and don't know if it is important

Jacked up front tire off ground with shop jack under suspension arm ( keep weight on arm ).
turned key on
ABS light on then off as normal
rotated tire a bunch
went back, looked at dashboard and ABS light was on.
This worked the same for the other side too.
Does this mean that front tire sensors are working and ECU is "seeing" tire rotation but no odometer change ?

One last thing: these TSB with relation to ABS are out there:
12216
12750
12776
14905
991313
99414

 

Yes I think what happened there was that the ABS saw one wheel spin and not the others...it didnt like that so it turned on the light.

As for testing, you can check the resistance of the sensors quite easily. The fronts should be 2000-4000 ohms and the rear should be 800-3500 ohms. Also pull the sensors out....very carefully as they do break.....and take a close look at the teeth on the exciter rings. If there are any teeth missing or any cracks in the ring that will cause problems.

 

 

I would like to disconnect my abs so I can pinpoint it to the abs,,, Is there a way to further pinpoint it down without throwing money down this hole?
The speed sensor ( a cable a foot long) costs 124 dollars.
Just want to narrow it down.
Will test as earlier described. Will keep you posted on results.
Later,
The Force