Ford Fusion did the sudden loss of brakes thing...am I screwed because its the ABS module?

[Eddo Rogue]

Module, yes. I've seen a bunch fail over the last several years, most of them on F150's. None of them caused a low pedal.

There is a specific failure that has to take place for an ABS HCU unit to cause a low pedal, which is a dump valve hanging open. Very rare.

Is there evidence of contaminants in the brake system (master cylinder cap seal swollen/distorted)?

Cap is clean but the lil rubber boot seal looking thing in the master cyl looks a lil beat up....dirty/dented

 

[Mechrick]

If it swells, that's an indication of petroleum contamination in the brake system. That can affect any rubber seals in the brake system including the HCU, calipers.

 

[19Walt93]

From what I read the abs module seems to be a somewhat common failure on these Fusions and other models w same setup. I don't recall much info on the HCU, but do remember one forum guy mentioning to change it along w the ABS.

I think and hope its just the master cyl....again from what I've read, if there is any pressure at all, the ABS is ok....and I do have some pedal pressure, just not enough to drive at road speeds confidently. Stops fine shuffling it around the driveway....just really low pedal.

As of May 2017, we never had to replace a Fusion ABS module so I wouldn't call it a common failure. Please have someone do an ABS bleed before you replace a bunch of parts.

 

[Mechrick]

I don't recall much info on the HCU, but do remember one forum guy mentioning to change it along w the ABS.

One important thing to remember, is the ABS module is not plug and play. Worse, sometimes you *must* have the original functioning module in the vehicle before you can program a new module with software.

Ford uses a configuration file called "asbuilt" that tells the module what it's installed in so it functions correctly. Most of the time we can pull the asbuilt information off Ford's servers, but occasionally you can't and the only recourse is to copy it from the original module. F150 seems to be the big offender. Always keep old modules on hand in case the programmer needs to do an inhale/exhale of asbuilt data.

We've had a few cases where the customer sent the old module in as a core, and we needed it. Without it, you can never make configuration error codes go away. Those of you that have played with Forscan, does it have the ability to fix this specific issue?

ABS modules cause codes and warning lights on the dash, but won't cause a low pedal. ABS HCU's can cause a low pedal but it's very rare.

I mentioned GM because GM trucks in the '90's had problems with inferior seals shedding rubber bits that would get back into the HCU and cause a spongy pedal. Also, some of the more current vehicles (Equinox, others) have a very fragile pressure sensor in the HCU that can be killed by pushing a caliper piston back in with the cap still on the master cylinder.

 

[Eddo Rogue]

I'll probably throw a master cylinder at it and get it ABS bled at a shop...After reading posts I dont think its the ABS module or anything like that...just air in the system and maybe the master cyl went bad from low fluid...

 

[Eddo Rogue]

Update. My ranger lost brakes too...diagnosed it to being the RABS...I didnt wanna deal w/ bypassing, so I bit the bullet and ordered one...This got me thinking. I will eventually need to ABS bleed the fusion whether I swap in a master cyl or not.

I have a Bosch 1150 scan tool which looks like it has ABS interface...Anyone have any experience with these scanners? It was the mid shelf priced one at Napa.

From what I gathered, the ABS is "unlocked" by the scanner to let the fluid pass through, which can then be manually bled....There's a procedure to it pedal wise, and then rinse and repeat if necessary...

Also I read driving on loose terrain and stomping the brakes to activate the abs will push the fluid through to then be manually bled.... skipping the need for ABS scanner to do it.

My other two options is get a pressure bleeder....or I do have a really good tire/ mechanic shop down the street that probably wouldn't charge me much for an ABS bleed...I bring him a lot of business and already drooled over his scanner, its a bad boy.

Watcha guys think?