2019 Ram 1500 (3 Errors - Service 4WD, Service ESC, Service Trailer Brakes)

[Gemlin]

Just had these three pop up while driving on the freeway.

Truck has the Maximum Care Extended Warranty (Just hit 60k miles).

Anyone every have all 3 of these pop up at once? Its going to the dealer once I call them on Monday. As luck has it, this happened after 5pm on a Saturday.

 

[Gemlin]

UPDATE: Previously the truck would NOT go into 4HI, Or 4LO. Today (in the morning) the Service ESC and Service Trailer Brake Controller messages vanished. In the morning the truck would NOT go into 4hi and 4lo.

Afternoon I noticed the Service 4WD light went off. Stopped the truck, put it in neutral. Hit 4LO, truck went into 4LO, hit 4HI, truck went into 4HI. Hit 4-Auto, it engaged. Hit 2WD, it goes back into 2WD.

I put the truck back into 4 LO, started to drive off, sure enough, it's in 4 LO. Put the truck back into 2WD. Drove off, as soon as I hit 15mph, "Service 4WD" came on.

However this time, I can actually put the truck into 4HI, 4Auto, 4LO. (The truck still has the Service 4WD light)

Tempted to unplug the battery to reset the light, however I want the dealer to see it.

Any clue what happened people?

 

[Richard320]

 

[Gemlin]

UPDATE again : All 3 codes came back, now 4WD does not work.

 

[Gemlin]

Well did a little searching and found the following thread on accident.

https://5thgenrams.com/community/threads/service-4wd-system-notification.33968/

Apparently people who had all 3 of these error lights had the 4WD Actuator fail in the front axle.

I have an appointment next week to get the truck looked at (Thats when they have the first available loaner).

 

[Gemlin]

I think I fixed it without going to the dealer tonight. Out of curiosity, I crawled under the front passenger side of the truck. I wiggled the wire harness going to the 4WD actuator and made sure it was plugged in and with good contact. Went to start the truck and all the lights went off.

Truck now shifts into 4wd (auto, hi and lo).

 

[silver billet]

Few weeks ago I dropped my front left wheel in a pretty severe ditch with a wooden box protecting it and had a really rough time getting out in reverse. 2wd just slipped so I tried 4 auto/high and neither would engage, got the "service 4wd" light on my gauge. Ever since then, no 4wd. Haven't had time to go to the dealer but I'm sure I just banged a sensor or wire loose somewhere by that wheel considering what I drove over (was maneuvering my trailer into position and wasn't paying attention).

So I'm curious, do you mind explaining a little more what you did with the harness, maybe a pic or two if you feel like crawling around?

 

[Gemlin]

I crawled under the truck on the passenger side front. Just near the edge of the skid plate (above it), you'll see the front axle and the wiring harness going to the 4WD Actuator (which is mounted to the axle). I removed the plug from the actuator and re-plugged it in. I Wiggled the wire near the plug. I crawled out from the truck, then started it. All the lights were gone and everything was normal.

Its either your wiring harness got knocked loose off of the actuator or your actuator is bad. From what I've read, those are the only two things that commonly throw that light.

 

[rngzc]

I had similar issue past month with my 2020 1500:

Intermittent serv 4wd light on along with ESC light on for 3 times in last month. (I do not have trailer package so no trailer brake lights I guess)

The diagnostic codes for the lights were: c1403, c140e, u0403, and u1440

I can always reset those lights by turning off and on the truck and the truck can also gear in between 4wd hi lo or auto no problems.

Still brought the truck to the dealer this week. Dealer, as I was told, fixed it by performing TSB 08-144-22. The fix is a software update to the drivetrain control module. Will watch if the problems come back.

Hope it helps other people with similar issues with their truck.

 

[Mattiusmaximus1216]

Any update to this? My truck has the same issues but goes into 4wd fine.

 

[rngzc]

The serv 4wd problem comes back after roughly 1 year since the dealer’s software update. Surprise! Will look into the issue.

 

[silver billet]

Ask your dealer to check the 4wd actuator plug/connection. It sits right below the oil filter and if the filter is tipped over when changing it out, oil can run into that harness and into the plug and cause electrical issues. Might just need to spray it out with brake cleaner and be on your way.

 

[rngzc]

Ask your dealer to check the 4wd actuator plug/connection. It sits right below the oil filter and if the filter is tipped over when changing it out, oil can run into that harness and into the plug and cause electrical issues. Might just need to spray it out with brake cleaner and be on your way.

Will give this a try! Thank you!

 

[rngzc]

Just took a look at it by myself today. The plug was indeed oily. Feel this is not the best design and dealership should pay more attention when changing oil. But it is what it is.

I do not have the brake spray at home but still went ahead to unplug connector, wipe the plug/contacts clean on both sides (the harness and the 4 prong inside the actuator side receiver) with shop towel and then plug the connector back in.

Will see if this can help save me a trip to the dealership.

For anyone who also have this issue: to remove the connector, you need to pull the red tab on the connector back towards wire direction first and then squeeze the top of the connector while wiggling/pulling it out. Search for some video on google will help too.

 

[rngzc]

Just to update. Apparently this fix is it. I never have Serv 4wd issue ever since.

It seems I cannot trust dealership to do the oil change properly.

 

[wrxified]

This is my first post. Glad I found this thread. I'm a new owner of a used 2020 1500. I picked it up a couple weeks ago with 73k miles. Everything has been really great up until a couple days ago. First I had the Service 4WD System light come on. Then it was followed with the message for ESC system and trailer brakes. I checked the connection on the front differential to the actuator and it seemed well seated. So disconnected it, cleaned the connectors and reseated them. I was hoping to have the same luck as Gemlin but it wasn't the case. Lights still on.

What's strange is the lights only come on in 2wd. I can get all 3 warnings to go away if I simply switch the drive selector to 4wd Auto or 4wd High. Sometimes it takes a minute or two but it will go away if I keep driving. I don't even need to shut off the vehicle. But the second I switch the selector back to 2wd it pops back up.

I'm hoping this will be covered by the powertrain warranty because I have 73k miles and worried they might point it at something electrical.

 

[wrxified]

I think I fixed it without going to the dealer tonight. Out of curiosity, I crawled under the front passenger side of the truck. I wiggled the wire harness going to the 4WD actuator and made sure it was plugged in and with good contact. Went to start the truck and all the lights went off.

Truck now shifts into 4wd (auto, hi and lo).

Ask your dealer to check the 4wd actuator plug/connection. It sits right below the oil filter and if the filter is tipped over when changing it out, oil can run into that harness and into the plug and cause electrical issues. Might just need to spray it out with brake cleaner and be on your way.

Hey all. Just a quick question for clarification. @Gemlin mentioned the actuator on the axle and the plug/unplug method. I found that and it didn't correct my problem. @silver billet mentioned the actuator plug connection below the oil filter housing. Is this for a gen 3 Ecodiesel? I don't see the connection you're referring to.

 

[silver billet]

Hey all. Just a quick question for clarification. @Gemlin mentioned the actuator on the axle and the plug/unplug method. I found that and it didn't correct my problem. @silver billet mentioned the actuator plug connection below the oil filter housing. Is this for a gen 3 Ecodiesel? I don't see the connection you're referring to.

I don't know where the oil filter is in on the ED. But judging by your two posts, you've already cleaned out the actuator plug I was referring to (which, on the hemi, is close enough to the oil filter that spilled oil can run down the harness under it and get into the plug).

 

[wrxified]

I don't know where the oil filter is in on the ED. But judging by your two posts, you've already cleaned out the actuator plug I was referring to (which, on the hemi, is close enough to the oil filter that spilled oil can run down the harness under it and get into the plug).

Ahhh. Got it. I thought you had the ED too as well. Thanks.

So I'm going to call the dealership today to set an appointment.

 

[Shaw44]

@wrxified did you get and answer about your ED I just bought a used 2020 a month ago and the lights popped up yesterday.