Ford OEM Brake Controller Modes

[Odyknuck]

My 2013 Ford F250 has Electric or Electric over Hydraulic mode selection with no other parameter adjustments. My new Disk brakes work in either mode and I do not notice much if any difference in them. Does anybody know what the controller does different in EOH mode? BTW the brakes work so much better than the Drum system. No comparison.

 

[Chuck_S]

Do you have EOH brakes on the trailer? Conventional electric brakes may work in either mode but EOH brakes seem to need that specific mode or at least brake controllers like my former Prodigy P3 (and current Ford) note that. I figure the engineers would not bother with a separate EOH mode if it wasn't necessary and run in standard mode.

-- Chuck

 

[Odyknuck]

I recently converted over to EOH Disk brakes with a Hydrastar actuator hence the reason for wanting to know what the controller does differently.

 

[Chuck_S]

Don't know "why" just that it's different enough to require a different setting. Nothing in the Ford manual other than to select that option if you have EOH brakes. Delay in the pump and how it maintains pressure maybe?

-- Chuck

 

[TitanMike]

I recently converted over to EOH Disk brakes with a Hydrastar actuator hence the reason for wanting to know what the controller does differently.

The difference depends on the actuator and how it communicates with controller. Some systems use digital signals and some analog. The general concensus is that if your system works on either it won't matter.

I'd just set the controller for the type of brakes you kniw you have and not dwell on the difference.

On my new F-150 I can set system up for e-brake, eoh, or none ane do so for eachvtrailer I tow. All memorized and I just select trailer I hook up to.

Remembering somebof my controllers from previous decades, I'm sure an EOH actuator might not work well with them. EOH brakes are becomming so commonplace they msy even "self adapt".

 

[Odyknuck]

I just would like to know the difference in modes as there does not seem to be any at this point.

 

[Mike134]

The only knowledge I have about them was given to me by google but it makes sense.

Electric only could have between 6-12 amps of draw on the brake circuit depending on number of axles you have.
Electric over hydraulic will have a much smaller current draw since you are only activating the "master cylinder piston". The brake controller might be looking for a certain amount of current depending on the setting.

I'm guessing that's why.

 

[Odyknuck]

The Hydrastar has an on board Hydraulic pump not a master cylinder per say.
Earlier versions of the Hydrastar required an adapter for a lot of controllers to see the higher impedance to function properly. Per the manufacture, recent units have lower impedance and the controllers reconize it as trailer connected and enable the output.

 

[wheelin14]

I absolutely agree with Mike134 that the only difference in the Elec. Brake or EOH settings is the amount of current (or actually lack of current) at which a controller throws an error code. Since most generic controllers would not know what type of actuator they are connected to, it would be difficult for controller manufacturers to program a response curve or other differences in the EOH setting. I believe that controllers determine a voltage output then evaluating the resulting current. However, this is based only on experience with Tekonsha or Ford OEM controllers (early versions->2012) running conventional drum brakes, a Dexter actuator, or (now) a BrakeRite actuator (owned by Dexter.)

 

[wheelin14]

Odyknuck, I will be very interested in how the Hydrastar system works with your 2013 Ford OEM controller. As I discussed back in your Odyknuck: Hydrastar Disk Brake thread I found our Ford 2012 OEM controller to have a unsatisfactory, non-linear, response curve connected to either a Dexter or BrakeRite actuator. Ford fixed that around 2015 or 2016 by adding an Aggressiveness setting of low, medium, or high. My solution was to add a Tekonsha P3 with boost setting on B3. It has its own problems sometimes requiring manual activation in certain situations. I’m very excited about a better fix picking up a 2024 F350 in a few weeks with the aggressiveness setting and a controller that responds to brake pedal push not deceleration.

 

[wheelin14]

TitanMike, I would love to hear about systems that use digital signals between the truck and the trailer. I’ve only come across the classic design that sends a voltage level back to the trailer. Presumably this could be a much smarter system with performance feedback to the truck. I believe that both Lippert and Dexter have (or, are in development of) stability systems on the trailer. But, as I understand it, both of these are self-contained on the trailer using the same old voltage signal from the truck.

 

[Chuck_S]

Enen with only a puppy in this dog fight I was curious and my current guess is some EOH brake systems (the brakes on the trailer) do not have enough impedance to allow some electric brake systems (the controller on the truck) to determine there's a trailer back there.

It's a brake detection not a brake application issue so as long as brakes are detected they'll work.

-- Chuck

 

[Odyknuck]

The controller in my truck sees the Hydrastar in either setting, so if the only thing is different is a current sensing Hydrastar fixed in the unit. There does not seem to be any braking difference.

 

[Chuck_S]

This matches my understanding/guess.

"Remember the recipe for Tiger Stew.

First, you have to catch the tiger." (Paladin, 1875 -- OK, 1959 )

(Substitute trailer for tiger.)

-- Chuck

 

[Odyknuck]

I Plan to leave it in EOH mode. I have only driven the rig for about 20 miles on flat ground ,so too early to tell how well it performs. My first trip is to Hatfield McCoy in southern WV Memorial day weekend, so we shall see. Worse case, I can always go with the aftermarket P3.

 

[Chuck_S]

Thanks, Wheeling14! I got impedance backwards. Too much impedance -- lack of current -- doesn't allow the brake controller to detect the trailer.

Technically you have it backwards. It should be “some EOH brake systems (the brakes on the trailer) have too much impedance to allow some electric brake systems (the controller on the truck) to determine there's a trailer back there.” Impedance and current are inverse to each other. With too much impedance, the current is very low causing the controller to think that there is a break in the wire.

-- Chuck

 

[wheelin14]

While researching the “Trailer Disconnected” problem below, I found this comment about the EOH setting on Blue Oval Forums. It was posted May 2023 in reference to a 2022 F-350. It may only apply to newer trucks, and I haven’t tested my 2024 to see if I agree.
“The EOH setting in the truck doesn’t help the truck recognize an EOH system, it only changes the programming to cut the gain to ZERO when the truck is not rolling. This prevents the EOH pump from running continuously when stopped, such as at a traffic light. You can change your setting to “Electric Brakes,” and you’ll probably not see the “Disconnected” message, but your pump will run at times it’s not necessary.”

As a side issue, I fixed our lack of aggressiveness problem with our disc brake setup by purchasing a new F-350. Following the owner’s manual I set the controller to EOH although it does not say “why.” I started getting “Trailer Disconnected” messages somewhat randomly but commonly after releasing the brake pedal or the manual activation lever. As an experiment I set the controller back to regular electric brakes, and so far, the messages are gone. Back in the day when we installed the disc brake system, I was throwing everything at it trying to get the system to work better. I ended up installing BrakeRite’s adapter to “fool” controllers with no EOH setting, so switching off EOH on our 2024 isn’t a valid experiment of what EOH actually does. At this point I’m not sure of anything, and it could be that different controllers do different things with their EOH setting.

 

[Odyknuck]

So an update on my Disk brake install using the OEM controller. There is an old saying that states "Pay once, Cry once" and this is a perfect example.
We got back yesterday from a 770 mile Offroad trip to WV and I am so pleased with the brakes as they stop very well unlike the crappy drum brakes I had. So glad I did this as I feel so much safer towing 14,000#s behind me. There is a slight timing difference between the truck brakes and the trailer brakes however not to the point I feel the need to change out to an aftermarket controller like the Prodigy 3. Thanks for all the assistance with my endeavor.