KeepOnTruckin
Junior Member
- Joined
- Apr 13, 2024
- Posts
- 1
- Reaction score
- 1
- Location
- Colorado
- Ram Year
- 2020
- Engine
- 6.7 I6 Cummins Turbo
Hello all,
I have a 2020 3500 Limited Crew Cab 60" C/A 4x4 with 6-speed automatic Aisin AS69RC HD transmission. After only 25,000 miles, the Serv 4WD caution light came on and stayed on at startup. Normally, this briefly turns on at startup and then goes out. Other than a few recalls, I've never have had any problems until this. I was gone for 2-weeks, so the truck sat plugged in to battery tender. When I returned, I drove about 4 miles and suddenly the Serv 4WD caution light illuminated along with a caution chime and instrument cluster displayed white text warning something like "Service 4WD". I wasn't trying to shift into/or using 4WD when light came on. I pulled over, turned off/on ignition and same result: light would stay on (solid vs. flash) and then periodically I'd get caution alarm and instrument text warning. I pulled codes and got a C1464 Front Axle Disconnect Control Circuit Low. So I tried changing the 4WD actuator (Mopar p/n 68449574AA), but this didn't fix the problem. I tried leaving the both batteries disconnected for 30-mins, but this didn't fix problem. Next, I changed the jumper harness--mainly because I broke it just trying to get the darn thing unplugged for the first time (Mopar p/n 52112344AD)--but this didn't fix the problem. (Tip: Push the red safety clip from behind with a small slotted screwdriver (screwdriver should be facing toward the back of the truck and push toward the bed.) After a bunch of testing this/that (not going to post all this), it turned out to be the DTCM (Drivetrain Control Module or Transfer Case Control Module p/n 68250127AC). Since both actuator and DTCM were covered under warranty, my local dealer replaced free of charge both of the parts. I paid for jumper harness. The DTCM is located in passenger foot area at firewall behind carpet in a box with cover. If ever I run into this problem again, I would try first disconnecting and reconnecting both plugs at the DTCM and see if just a loose/poor connection isn't the problem. As noted above, I tried a new actuator and so did the dealer--which didn't fix the problem. Swapping the DTCM did. It makes me wonder if there was nothing wrong with the actuator--and perhaps even the DTCM--and it was just loose/poor connection(s) at DTCM?
Hope this helps others.
I have a 2020 3500 Limited Crew Cab 60" C/A 4x4 with 6-speed automatic Aisin AS69RC HD transmission. After only 25,000 miles, the Serv 4WD caution light came on and stayed on at startup. Normally, this briefly turns on at startup and then goes out. Other than a few recalls, I've never have had any problems until this. I was gone for 2-weeks, so the truck sat plugged in to battery tender. When I returned, I drove about 4 miles and suddenly the Serv 4WD caution light illuminated along with a caution chime and instrument cluster displayed white text warning something like "Service 4WD". I wasn't trying to shift into/or using 4WD when light came on. I pulled over, turned off/on ignition and same result: light would stay on (solid vs. flash) and then periodically I'd get caution alarm and instrument text warning. I pulled codes and got a C1464 Front Axle Disconnect Control Circuit Low. So I tried changing the 4WD actuator (Mopar p/n 68449574AA), but this didn't fix the problem. I tried leaving the both batteries disconnected for 30-mins, but this didn't fix problem. Next, I changed the jumper harness--mainly because I broke it just trying to get the darn thing unplugged for the first time (Mopar p/n 52112344AD)--but this didn't fix the problem. (Tip: Push the red safety clip from behind with a small slotted screwdriver (screwdriver should be facing toward the back of the truck and push toward the bed.) After a bunch of testing this/that (not going to post all this), it turned out to be the DTCM (Drivetrain Control Module or Transfer Case Control Module p/n 68250127AC). Since both actuator and DTCM were covered under warranty, my local dealer replaced free of charge both of the parts. I paid for jumper harness. The DTCM is located in passenger foot area at firewall behind carpet in a box with cover. If ever I run into this problem again, I would try first disconnecting and reconnecting both plugs at the DTCM and see if just a loose/poor connection isn't the problem. As noted above, I tried a new actuator and so did the dealer--which didn't fix the problem. Swapping the DTCM did. It makes me wonder if there was nothing wrong with the actuator--and perhaps even the DTCM--and it was just loose/poor connection(s) at DTCM?
Hope this helps others.
Last edited:
