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

[Spindrifter]

I was getting the dreaded ABS messages so I purchased the AlphaOBD software (PC) and the OBD Link EX cable, along with the security cable for 2018+ Rams. Running the scan, it came back with ABS codes C0020 and U0151.
I couldn't "Initialize ABS" because there was no communication. So I decided to do a "Bleed ABS" routine which was available. I could feel the pump activating each time, so it appeared the pump was working. After running through that sequence and getting the "complete" message, I shut the truck off and disconnected everything. Upon restart, no codes and no issues. I drove the truck for a few days and hard braked a few times and the ABS kicked in as required. It appears the problem is fixed. I did run a rolling sensor test and everything looked great.
So, this might be something to try before you start buying sensors and parts. I just wanted to pass this along if it may say someone else the money and frustration. Maybe the pumps appear bad, when all they need is a bleed.

 

[Jeepwalker]

Great tip...

I wonder if there could have been a stuck solenoid, a cold solder joint or bad wire connection which was vibrated 'good' by the slight movement of the pump and/or valves as it went through the bleeding process? Hmmmm...

Thanks for sharing.

 

[Spindrifter]

Great tip...

I wonder if there could have been a stuck solenoid, a cold solder joint or bad wire connection which was vibrated 'good' by the slight movement of the pump and/or valves as it went through the bleeding process? Hmmmm...

Thanks for sharing.

I just can't help but wonder how many components have been replaced when maybe all that was needed was an ABS bleed...

 

[Choupique]

I'll give this a try this evening with mine and report back

Had to work late, so maybe tomorrow...

 

[Choupique]

I was getting the dreaded ABS messages so I purchased the AlphaOBD software (PC) and the OBD Link EX cable, along with the security cable for 2018+ Rams. Running the scan, it came back with ABS codes C0020 and U0151.
I couldn't "Initialize ABS" because there was no communication. So I decided to do a "Bleed ABS" routine which was available. I could feel the pump activating each time, so it appeared the pump was working. After running through that sequence and getting the "complete" message, I shut the truck off and disconnected everything. Upon restart, no codes and no issues. I drove the truck for a few days and hard braked a few times and the ABS kicked in as required. It appears the problem is fixed. I did run a rolling sensor test and everything looked great.
So, this might be something to try before you start buying sensors and parts. I just wanted to pass this along if it may say someone else the money and frustration. Maybe the pumps appear bad, when all they need is a bleed.

Did you actually bleed the brakes or just run the program without opening any bleeds

 

[Spindrifter]

Did you actually bleed the brakes or just run the program without opening any bleeds

I did a mock bleed. I bought fluid to actually bleed the system, but I wanted to try tricking the system first and it worked.

 

[Choupique]

Mock bleed meaning didn't actually open anything? I just want to make sure I duplicate exactly what you did for the sake of troubleshooting when I finally get to take a failed HCU apart.

 

[Spindrifter]

Mock bleed meaning didn't actually open anything? I just want to make sure I duplicate exactly what you did for the sake of troubleshooting when I finally get to take a failed HCU apart.

Correct, I didn't open anything. Just held my foot on the brake and let it cycle each wheel. The pump will activate then the pedal will go to the floor on each one.

 

[Choupique]

Roger. I'll get to this at some point here and report.

 

[Choupique]

Performed the bleed this morning and have driven about 150 miles so far with no chimes. This happened before after I had the fuse out for a few days so I'll report back after I go fishing tomorrow. Looks like it'll buy you at least half a day of having cruise control!!!

It did noticeably improve my pedal feel, which makes me wonder if it was ever bled properly after the first HCU was changed. I suppose I'll do an actual full bleed when I get time.

Mine never asked me to open any bleeds. I guess the the thing is smart enough to know whether or not it has air.

 

[CanuckRam1313]

Just tossing this out there.... although I have a 19' and it's a 1500 with the HEMI, perhaps the theory could be the same?!

Have you ever flushed and filled the brake fluid?
I am a huge proponent of predictive and preventative maintenance, and I do a brake fluid flush and fill at least every three years.

Brake fluid degrades and gets full of moisture over time, plus it gets hot and loses its properties too, especially if the brakes have been used hard over their life cycle (with a Cummins, usually towing and hard work go hand-in-hand). This can have negative effects on the ABS pump and solenoids/actuators and potentially cause issues, and it leads to spongy brakes and a lack of true pedal feel.

I always upgrade to high high quality brake fluid when I do this, and never go back to stock brake fluid because it's a base fluid and is a bare minimum grade to "just" meet requirements by the OEM.

I had new brakes installed 2-days ago (PowerStop Heavy Duty) and did the full brake fluid flush and fill too. My tech uses a brake bleeder vacuum machine that connects clear tubing lines to all four caliper bleeders, and cracks them open so its sits static and won't allow back flow / air to enter into the brake fluid system.

Then sets the brake fluid bottle jig on top of the master cylinder and tips an open bottle of brake fluid on top and starts the machine. As it sucks down the bottle and the mater cylinder is full but the bottle is empty, a new bottle is tipped on top. This is done until all four calipers have fresh new fluid being pulled out. The passenger rear caliper is commonly the last line to run clear fresh fluid as it's the furthest away from the master cylinder.

I used this https://www.motul.com/ca/en/products/dot-5-1-brake-fluid - and each bottle is 500ml. It took pretty much 4 bottles to do a complete flush and fill.

What a noticeable improvement in brake pedal feel and pressure!

 

[Choupique]

Sitting in traffic now listening to the lovely DING DING DING DING DINGDINGDING

UGHHHHHHHHH

 

[Spindrifter]

Performed the bleed this morning and have driven about 150 miles so far with no chimes. This happened before after I had the fuse out for a few days so I'll report back after I go fishing tomorrow. Looks like it'll buy you at least half a day of having cruise control!!!

It did noticeably improve my pedal feel, which makes me wonder if it was ever bled properly after the first HCU was changed. I suppose I'll do an actual full bleed when I get time.

Mine never asked me to open any bleeds. I guess the the thing is smart enough to know whether or not it has air.

Good news! I hope this can save some headache for some. I’m still riding with no codes. Drove about 500 miles since…

 

[Spindrifter]

Sitting in traffic now listening to the lovely DING DING DING DING DINGDINGDING

UGHHHHHHHHH

Damn, sorry man. I’m still riding good… 500 miles so far. Maybe try really bleeding it this time? Let us know how it goes

 

[Choupique]

I'm going to do that at some point. This is such an aggrevating issue. I think it's an intermittent ground fault, but there's some weird things that make me wonder. Pulling the fuse for a little while and putting it back in will almost always give me a day or two of no chimes at all. Then one startup it'll start freaking out again. It's almost like the BCM gets more sensitive to it after it happens once or twice.

 

[RedRam55]

Not sure if it is the same thing, but my ABS pump had a bad motor. The motor had a dead spot and it would not activate properly. I ran through the bleed process (mock) and sometimes it would work for a while. Other times I would stomp on the brake on my dirt road and that would work. Other times I would just hit a bump and the light would go off. When the light was on, the cruise control would not work. Finally after reading here and a RAM bulletin, I swapped out the ABS pump. Over 5K later, still ok.

 

[Dginn69]

Good info but could you describe the "mock" bleeding process? Are you saying to just have someone pump the pedal several times to simulate bleeding each wheel? Or is there another process? Thank you in advance.

 

[Nystagmus]

Will this work on older models ?
My 2014 Longhorn has the same problem.

 

[James Winkelman]

Any have an autel mx808...mine says brake bleed function is not supported..anyone have any experience with doing this on an autel tool

 

[Spindrifter]

Good info but could you describe the "mock" bleeding process? Are you saying to just have someone pump the pedal several times to simulate bleeding each wheel? Or is there another process? Thank you in advance.

Yep, I just pressed the pedal when it instructed and it would pulse then go to the floor. I did it on each wheel, then cleared the codes, and disconnected the computer. Restarted the truck and no codes or warnings. Still riding good so far…