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

[wrxified]

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

Not yet. I went to the dealership to set an appointment. They couldn't get me in for service until October 5th which blew my mind but I took the appointment either way.

Since I set it up the lights have gone off and come back on twice. They were off for the last week and my wife said something about how they weren't on last night and then of course they popped on 5 minutes later.

I thought I noticed a weird pattern to how they come and go. Twice now I noticed that if I am making a turn, and lightly accelerating, I will get kind of a small thump while the transmission shifts from 1st to 2nd gear. It's by no means a violent shift but just slightly more aggressive than usual. Twice right after that the service 4wd light has popped on. It's always just the Serv 4wd warning when it happens, but then when I shut the car off it comes back on with that warning in addition to the ESC and trailer brake warning.

On one occasion making the same type of turn while they were already on, the transmission made the same type of shift and they actually went off.

That behavior has me a little concerned because I'm not in 4wd hi or 4wd auto when it does it so I can't see how the actuator could be causing the issue. Worried it might be the transmission itself.

 

[Shaw44]

Not yet. I went to the dealership to set an appointment. They couldn't get me in for service until October 5th which blew my mind but I took the appointment either way.

Since I set it up the lights have gone off and come back on twice. They were off for the last week and my wife said something about how they weren't on last night and then of course they popped on 5 minutes later.

I thought I noticed a weird pattern to how they come and go. Twice now I noticed that if I am making a turn, and lightly accelerating, I will get kind of a small thump while the transmission shifts from 1st to 2nd gear. It's by no means a violent shift but just slightly more aggressive than usual. Twice right after that the service 4wd light has popped on. It's always just the Serv 4wd warning when it happens, but then when I shut the car off it comes back on with that warning in addition to the ESC and trailer brake warning.

On one occasion making the same type of turn while they were already on, the transmission made the same type of shift and they actually went off.

That behavior has me a little concerned because I'm not in 4wd hi or 4wd auto when it does it so I can't see how the actuator could be causing the issue. Worried it might be the transmission itself.

Okay my appointment is on the 25 of October I will post what they say. I am sure you will get an answer before I do please post.

 

[JF19Longhorn]

Same error happened to me while dropping the youngest off to Pre-K. Shut the truck off to get him out of the car seat, when I started her backup.. every light on the dash lit up, beeping, E-brake engaged.. shut off and back on, changed nothing. Drove the POS home and it seemed to drive fine.. called the dealership, earliest they can get the POS in is the 10th.

I'll have to check that harness.. though it's yet another thing we shouldn't have to deal with on a truck that less than 4yrs old.

2019 @ 57k miles

 

[JF19Longhorn]

It appears that disconnecting the battery, jiggling the wiring harness, and letting her sit for 45+ minutes cleared everything. Drove around the block and then to lunch without any unwanted lights on the dash.

Shifts in and out of 4wd (auto) with no issues.

I'm going to keep the appointment scheduled just incase.

Sidenote: I did lose all my Uconnect features & options for acouple hours. I read that's normal for a loss of power to the system.

 

[wrxified]

I dropped mine off yesterday for the repair and heard back late afternoon confirming that it was indeed the 4wd axle locker actuator. Sounds like they have one in stock and are replacing it. Hopefully it’ll be done today.

 

[Edwards]

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.

Thanks for this! Just had it happen and cleaning out the connector fixed it right up. Now to figure out how to prevent it from happening again!

 

[Aduncan78]

Okay my appointment is on the 25 of October I will post what they say. I am sure you will get an answer before I do please post.

I searched high and low for an answer to a similar problem. My 2020 RAM 1500 Laramie Longhorn threw a Service ESC and SERV 4WD code at the same time after shifting into 4WD. The transfer case would intermittently indicate that I was in 2wd and had no problems indicating 4wd. The problem lasted for several weeks intermittently... took it to the dealer and they had no clue and just wanted to throw parts at it. I ended up ordering a new 4wd actuator (4th one on this truck, 3 Mopars and 1 aftermarket) and installing it. Both service codes have gone away after install of the new actuator. Shifts from 2wd to all 4wd modes and back with no problem and the proper indicator on the dash.
In my experience, the 4wd actuator on the 5th gen rams is junk. On top of that, they designed the truck so that the oil filter is directly above the electrical connector to the 4wd actuator, causing it to be soaked in oil at every oil change.
After replacing the 4wd actuator 3 times, I've noticed a couple of things:
1. If the truck shows SERV 4WD and has problems shofting into 4wd, the actuator has failed in the open (2wd) position.
2. If the truck shows "Service ESC" AND "SERV 4WD," the actuator has failed in the closed (4wd) position.... which probably explains my terrible gas mileage lately.
From now on, I will keep an extra 4wd actuator, a tube of xfer case fluid, and a 12mm socket in the bed of the truck... and WILL NOT buy another overpriced Mopar replacement.

 

[Cbty2050]

I searched high and low for an answer to a similar problem. My 2020 RAM 1500 Laramie Longhorn threw a Service ESC and SERV 4WD code at the same time after shifting into 4WD. The transfer case would intermittently indicate that I was in 2wd and had no problems indicating 4wd. The problem lasted for several weeks intermittently... took it to the dealer and they had no clue and just wanted to throw parts at it. I ended up ordering a new 4wd actuator (4th one on this truck, 3 Mopars and 1 aftermarket) and installing it. Both service codes have gone away after install of the new actuator. Shifts from 2wd to all 4wd modes and back with no problem and the proper indicator on the dash.
In my experience, the 4wd actuator on the 5th gen rams is junk. On top of that, they designed the truck so that the oil filter is directly above the electrical connector to the 4wd actuator, causing it to be soaked in oil at every oil change.
After replacing the 4wd actuator 3 times, I've noticed a couple of things:
1. If the truck shows SERV 4WD and has problems shofting into 4wd, the actuator has failed in the open (2wd) position.
2. If the truck shows "Service ESC" AND "SERV 4WD," the actuator has failed in the closed (4wd) position.... which probably explains my terrible gas mileage lately.
From now on, I will keep an extra 4wd actuator, a tube of xfer case fluid, and a 12mm socket in the bed of the truck... and WILL NOT buy another overpriced Mopar replacement.

Maybe it's never the actuator. You replacing the actuator actually masks the real issue.

 

[silver billet]

I searched high and low for an answer to a similar problem. My 2020 RAM 1500 Laramie Longhorn threw a Service ESC and SERV 4WD code at the same time after shifting into 4WD. The transfer case would intermittently indicate that I was in 2wd and had no problems indicating 4wd. The problem lasted for several weeks intermittently... took it to the dealer and they had no clue and just wanted to throw parts at it. I ended up ordering a new 4wd actuator (4th one on this truck, 3 Mopars and 1 aftermarket) and installing it. Both service codes have gone away after install of the new actuator. Shifts from 2wd to all 4wd modes and back with no problem and the proper indicator on the dash.
In my experience, the 4wd actuator on the 5th gen rams is junk. On top of that, they designed the truck so that the oil filter is directly above the electrical connector to the 4wd actuator, causing it to be soaked in oil at every oil change.
After replacing the 4wd actuator 3 times, I've noticed a couple of things:
1. If the truck shows SERV 4WD and has problems shofting into 4wd, the actuator has failed in the open (2wd) position.
2. If the truck shows "Service ESC" AND "SERV 4WD," the actuator has failed in the closed (4wd) position.... which probably explains my terrible gas mileage lately.
From now on, I will keep an extra 4wd actuator, a tube of xfer case fluid, and a 12mm socket in the bed of the truck... and WILL NOT buy another overpriced Mopar replacement.

Just install a pacbrake oil filter relocation kit which moves the filter closer to the bumper. You get very easy access to the filter for oil changes, no messy spills, and no more actuator issues. Been there, done that. Never had a problem with my actuator since installing the kit.