Vehicle: 2005 FEH
Symptoms:
Yellow ABS light
Red Brake warning light
Service Brake System message
No pressure priming sound when I first open the door
No regen braking
NORMAL friction braking power.(Like I would expect from any non-hybrid SUV)
Servo sound when brake pedal is pressed.
Warning lamps did not reset after unhooking both batteries for ~90 minutes.

For the past few months, every once in awhile the abs would kick in with the Anti-Skid warning blinking when stopping under normal conditions. If I released the brake and re-applied this would go away.
Everything else with the FEH is functioning normally.
We have had a lot of winter road treatment here in VA, and the underside of the FEH is mostly white with the salt and treatment residue.

I have read about the $4500+ HCU failure, but all of those instances seemed to be accompanied by a dangerous lack of friction braking power. I seem to have perfectly good friction braking power. The nearest FORD stealership is a good hour away from me. I do have a ScanGauge but do not know the appropriate gauges to program it with to be able to read problems from the ABS.

Any ideas??? Thanks in advance for any help!

 

Simple answer: cracked tone ring.

 

I could see a cracked tone ring being the cause of the occasional skid warning, but could that also be the cause of the new development of the abs light/Brake warning light/no Regen braking? Those issues all just started Thursday morning

 

A cracked tone ring caused all those issues and more last July. It is the pits when your vehicle is jerking, losing regenerative braking, 4wd function and all means of safety due to cracked tone rings and an inoperative speed sensor. It happened to me this past July at the start of a long weekend vacation drive. I had to rent a vehicle for the trip and pay the repair bill when I returned.

 

Thanks for the help!
Found a broken tone ring (FL). Went ahead and ordered 2 from Rockauto.com for ~$11 with shipping. Crossing my fingers that this will fix it.
Would I be able to clear the DTC with my scangaugeII?

 

Hope the tone ring works - it may very well. Just a tip for others, I have successfully temporarily epoxied two tone rings on. You need to clean up both surfaces really well and use a good epoxy like JB weld. Keep the slots clean on the outer edge.

 

Seconded on using epoxy. I used jb weld on mine about ten thousand miles ago. The "normal" repair takes much longer, requires tools many do not have, and is honestly more likely to fail again in the future. The only reason not to use JB Weld would be if you can't put the truck somewhere warm overnight, if your state is colder than about 50 right now.

 

Right - isn't the "normal" dealer fix a new half shaft to the tune of about $500?

 

Replaced a tone ring 50k ago. A replacement tone ring is no more likely to fail than the OEM rings. In essence rust gets under the ring and fractures it. Rust takes up twice the volume of the constituents that went into it: so it builds pressure under the ring til it breaks.

The ABS and regenerative braking need signals from the tone ring to operate properly. The system recognizes the extra large gap at the break and shuts down. This leads to only regular braking.

I wouldn't use JB weld. Replacing the tone ring is not that difficult.

 

While I agree that replacing the ring is a better fix, I have found that after epoxying the ring, the ABS does continue to function. This winter has provided numerous opportunities to test it out. Maybe it depends on the size of the gap.