New member having ABS issues

[Truckmannorth]

Hi all
Bought a 2018 2500HD with the 6.4 a couple of weeks ago and I am so impressed with this truck.
I have an interesting issue going on and hoping some one here can help. When I am pulling my small utility trailer. (Single axle no trailer brakes) I get an intermittent service ABS/Traction control light. Once I disconnect the trailer the issue goes away. Now I'm no stranger to cars and trucks. I've been a professional mechanic for the last 30 years. I double checked the trailer for shorts, bad grounds, water logged lights etc. and it's fine. I also don't understand how the lighting system could cause an ABS issue. Our scanner at work needs updating and stops at 2017 so can't use it to find what code is setting. Have an appointment to take it to the dealer next week but thought I would pick the collective minds here.
Thanks in advance and thanks for such a great site. I've been pouring over it for the last week.

 

[jr27236]

Are you using the round 7-way plug or the flat 4-way. It is possible that your trailer is not wired properly with the rams wiring.

 

[Truckmannorth]

I am using the flat 4 way plug. Should be the standard configuration I think.

 

[62Blazer]

I would check the pin on the truck trailer connector that is used for trailer brakes and make sure it is not connected to a pin on the trailer harness. Though I would think if this was the case you would have an issue with some of the trailer lights (brakes, running, turn). Next would be a visual inspection of the truck trailer connector, both front and back, and look for any shorted wires or bent pins.

 

[jr27236]

I know with my truck once I connect my trailer it knows to shut off the rear park sense so it it not sounding because of the trailer. I would check out the functions of each pin to confirm there is no conflict with the trailer

 

[Truckmannorth]

So I double checked that there was nothing wrong with the trailer. I looked over all of the wiring on the truck side. Plugs are all clean and when I check them with my test light I get the correct outputs from all of the pins. Also as of today it has started doing it without the trailer attached. I'm thinking it was just coincidence that it happened with the trailer. I talked to the service manager at the dealership and he's going to get it in this week to find out what's wrong. If our scanner at work was updated I be doing it my self but the boss is not ready to update yet.

Thank you everyone that responded I truly appreciate your help.

 

[Truckmannorth]

Just thought I would post an update. Got the truck back from the dealer. Problem turned out to be the ABS hydraulic unit. They replaced it under warranty. All good now.

 

[allen wallace]

I have the 2015 Ram 1500 with hemi. Last October my dash light came on also. Traction, ABS, and Brake. Dealership said it was a wheel sensor (replaced it). Also, they said I need to have a new hydraulic unit and module ordered. They needed $1800 for those to place order. In January of this year I called to find out that they could get the hydraulic unit but we’re still waiting on the module as it was back ordered. I told them I need to know when to bring the truck in. When will you get the module? Now, they tell me that they can’t get the module until January 2023 and Detroit keeps deleting their request for expediting. I made them refund my $900 for the module until I can find one myself. This leaves a bad taste in my mouth for future Ram purchases. @RamCares

 

[Mountaineer83]

I got the warning light on my 2016 last week. Ordered the new HCU and will be replacing it hopefully within the next week. I found the part from a dealer for about $260. I've read you don't have to replace both pieces, and some who did replace both had more issues than those who simply replaced the hydraulic control unit alone. We shall see!