Potential fix for the dreaded "Service ABS system" "Service Electronic Braking System" messages

[Choupique]

AB is the updated part but hasn't been available. AA can be found online.

All of our 2018 2500's in our fleet have had this problem several times over. Prior and latter year models have not. This should be REALLY easy for Ram to fix.....

 

[Spindrifter]

I’m still riding problem free after over 800 miles. Time will tell though, I’d put money on my problem coming back at some point.

 

[Choupique]

I swapped my HCU out today. A few things to note:

My old HCU was absolutely shot. It made almost no noise at all when doing an ABS bleed, and I had no prior experience to compare it to. The new one is quite noisy and clearly doing work, where as my old one didn't do anything. If yours is still pumping, this might still work. It should be tried before your pump completely quits like mine did.

Bleeding everything properly is near impossible solo. I seriously doubt the dealership had ever bled mine completely. I ran almost a half gallon of fluid through mine.

I'm going to take my old HCU apart when I get a chance and see what's wrong with it.

 

[Spindrifter]

I swapped my HCU out today. A few things to note:

My old HCU was absolutely shot. It made almost no noise at all when doing an ABS bleed, and I had no prior experience to compare it to. The new one is quite noisy and clearly doing work, where as my old one didn't do anything. If yours is still pumping, this might still work. It should be tried before your pump completely quits like mine did.

Bleeding everything properly is near impossible solo. I seriously doubt the dealership had ever bled mine completely. I ran almost a half gallon of fluid through mine.

I'm going to take my old HCU apart when I get a chance and see what's wrong with it.

It would be great to see some pictures when you get it apart. Thanks for the update!

 

[Spindrifter]

I swapped my HCU out today. A few things to note:

My old HCU was absolutely shot. It made almost no noise at all when doing an ABS bleed, and I had no prior experience to compare it to. The new one is quite noisy and clearly doing work, where as my old one didn't do anything. If yours is still pumping, this might still work. It should be tried before your pump completely quits like mine did.

Bleeding everything properly is near impossible solo. I seriously doubt the dealership had ever bled mine completely. I ran almost a half gallon of fluid through mine.

I'm going to take my old HCU apart when I get a chance and see what's wrong with it.

Ever take that thing apart? Interested to see what's going on in there...

 

[Choupique]

Ever take that thing apart? Interested to see what's going on in there...

Yes. I made a separate thread with pictures. It's in the HD forum

 

[18CrewDually]

Ever take that thing apart? Interested to see what's going on in there...

Yes. I made a separate thread with pictures. It's in the HD forum

Link is here:

Thread '2018 Failed ABS HCU Teardown' https://www.ramforum.com/threads/2018-failed-abs-hcu-teardown.199515/

 

[jethomas15210]

I have a 2018 RAM 2500 Diesel which is now experiencing the dreaded "Service Electronic Braking System" syndrome for the 3rd time. First time ii occurred around 17K miles, had he ABS module replaced under warranty. Second time around 85K miles, thank god I had an extended warranty, ABS module replaced again. Just passed over 101K miles and the problem has returned and my extended warranty expired at 100K. Based on all the discussions that everyone had posted on-line there is an obvious problem that no one seems to be able to pinpoint the exact cause. Love the truck, hate the service departments. I think people are guessing to the real problem and try different things that mask or hide the problem for a period of time. Anybody have any real conclusive evidence that they have actually fixed the problem and just aren't holding their breath hoping the problem doesn't reoccur? Sure wish somebody at RAMcares would step up.

 

[Nystagmus]

I just want my damn cruise control
back !!!

 

[Choupique]

Reportedly the -AB revision of the HCU is an improved part and addresses the problem. Availability is getting better from what I have read on here. I have not gotten my hands on one of those. I'm on my 3rd -AA revision HCU in my 2018.

A couple of us have broken down the failed HCU and identified what the problem is. There's some chance you could have a local starter/alternator repair shop fix it. The motor brushes lose contact intermittently with the rotor causing an open circuit and all the dinging.

Unfortunately, there's no way to make the cruise control work that I have found. I did a bunch of digging in alfa OBD for some setting to de-couple the cruise control from the ABS system and never found anything. If someone does, it'd help a lot of people out.

 

[appzattak]

I just want my damn cruise control
back !!!

Me too!!! I wish there was a way to bypass this error with a tune, so at least CC would work.

 

[Nystagmus]

Can you erase the codes with an OBD2 scan tool and get the cruise to work again ?

 

[Choupique]

Basically No. The faults clear instantly if the fault condition goes away because it's a brake system fault. There's no deadband at all on those faults, which is why the dash goes disco on you on a bumpy road.

If you have an active fault, you can clear it but it'll instantly come back.