2026 Ram 3500: check engine light

Filed Aug 5, 2026 · Driver assistance, Electrical · FL

Started with only 320 miles just days after purchasing this new 2026 RAM 3500 on XXX. I have taken the truck to three differ RAM dealerships as this issue continues to occur. [XXX]; [XXX]; and [XXX] Westside all had attempted to fix the issue. I had to return the truck a number of times to [XXX] and [XXX] for the same reasons. The following warmings messages are displayed: FCW/Cruise Control Unavailable Service Required - occurs when using cruise control, Service Electronic Stability Control, Auto Emergency Braking (AEB) Unavailable Service Required, Park Sense Temporarily Unavailable, Service Antilock Brake System, 4WD System Temporarily Unavailable, and Service engine light comes on. Two RAM dealers are saying the issue is the speed sensor, which has been replaced over three times. The RAM dealership had to open an engineer ticket with the manufacture, but the issue is not fixed. The Jacksonville service manger told me I can keep bringing the truck in, but until a different manufacture makes a new speed sensor, the truck will continue to have the same issue. I use the RAM 3500 to pull my RV. Brake system failure put myself and family and others safety at risk while on the road, therefore, I do not drive the truck in fear the brake system will fail and I won't be able to stop 20,000 pounds of truck and RV. The truck is available for inspection, but I am currently in the process of returning the truck under Flordia's Lemon Law. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 21, 2026 · Brakes, Driver assistance · ND

Just driving down the road and abs service, traction control service, 4wd service, automatic emergency brake disabled front and rear sensor service lights come on then go off and come back on later with a check engine light vehicle has less than. 500 miles

Filed May 7, 2026 · Acceleration, Driver assistance · TN

Vehicle sends cluster warnings about Auto Emergency Braking unavailable/inoperable, Electronic Stability Control needs service, Antilock Brake System needs service, Parksense Unavailable, and ultimately the Check Engine indicator illuminates after restarting the vehicle. An error code also is present in the computer, U1412. This has happened twice now in a two week period. These systems are critical to safe operation of he vehicle, especially in emergency braking conditions, and could affect both the operator and the general public if they indeed failed. The vehicle has not been inspected by the manufacturer, yet, and is scheduled for 5/8/2026

Filed Apr 20, 2026 · Acceleration, Brakes · FL

This is related to the 2025/2026 Ram 3500 U1412 code relating to anti lock brake system. On this date I got an ABS warning light and check engine light. The vehicle would not turn off, was not sure if it was in gear or not, and multiple other lights came on the dash. Vehicle towed to dealership. They said they could not reproduce the error and that all the codes disappeared due to the batteries dying overnight. They replaced both batteries and returned vehicle. Have since had same problem twice more with one requiring towing again. If this problem happens on roadway while being operated it would be very dangerous on roadway.

Filed Mar 5, 2026 · Brakes, Driver assistance · AL

Shortly after purchasing a new 2026 Ram 3500 in January 2026, the vehicle began displaying multiple safety warnings simultaneously while driving. Warning indicators included Check Engine, ABS, Brake, Traction Control, Electronic Stability Control, Forward Collision Warning, and Automatic Emergency Braking, along with a “Service Electronic Stability Control” message. The vehicle had very low mileage when the issue first occurred. The vehicle was taken to the dealership for diagnosis and repair. The dealership indicated the concern involved rear wheel speed sensor(s) and the vehicle’s electronic control systems (including a Body Control Module software update). Multiple repair attempts were required, including sensor replacement(s) and software updates, with manufacturer engineering involvement. The dealership and engineering instructed extended test driving (hundreds of miles total) to verify the repair. A particularly concerning element is that a replacement sensor reportedly failed without producing a diagnostic code, meaning the driver may have no warning that a critical component failed until safety systems disable or the vehicle behaves erratically. When the issue occurs, multiple safety systems are impacted at the same time, including ABS braking, stability control, traction control, and AEB/forward collision systems. Multiple safety systems disabled simultaneously. Dealership personnel also indicated that these wheel speed sensors are experiencing widespread failures and that replacement sensors can fail again shortly after installation as they have a 67% failure rate, which raises concern that this may represent a broader manufacturing or component defect affecting multiple vehicles. This complaint is submitted to document a potential safety defect affecting braking, stability control, and driver assistance systems.

Filed Feb 13, 2026 · Electrical · CO

4 times in less than 4000 miles my 2026 trucks abs, cruise control, skid control, and check engine warnin07g lights have come on. I then have no anti-lock system, no cruise control, no 4-wheel drive, and no anti-skid system. Code reads-U1412. The dealer has replaced the rear speed sensors and it continues to happen. My truck is currently at the dealer in the service bay as I can't drive it. I've researched this and it's happened to many who have purchased this truck.

Filed Jan 8, 2026 · Brakes, Engine · 458 miles · MN

The contact owns a 2026 Ram 3500. The contact stated that while driving at an undisclosed speed, the check engine, 4WD, ABS, park sensors, and several other unknown warning lights illuminated. The vehicle was taken to the dealer, who replaced the speed sensor for the rear wheels; however, the failure persisted, and the transmission failed to recognize that the gear selector was in park(P). Roadside Assistance arrived and unplugged the battery cables to turn off the engine. The vehicle was towed to the dealer and was waiting for engineers to diagnose the vehicle. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 458.

Filed Dec 23, 2025 · Engine · IA

Purchased the truck new with 25 miles on it from the dealer. Within the first 2000 miles, I had a message pop up that said "Service Exhaust System See Dealer". I took it in to the dealer, they said it showed a random emission related code had popped up but was not currently active, so their recommendation was to clear it and see if it came back. Within a day, the message was back and tripped a check engine light. I also noticed after the first 1000 miles, my fuel mileage dropping off significantly around the time the "Service Exhaust System" message first appeared. (I went from 18-19 mpg average, to 12-14 mpg average, driving the same commute to and from work, in the same conditions.) I have noticed unusually high temperatures in the exhaust at times, excessive fuel consumption, excessive DEF consumption, and am concerned about the potential for damage to the DPF or DEF system. I took the truck to my local dealer for diagnosis and repairs. They called me to say that the problem had been traced to a faulty Exhaust Gas Temperature (EGT) control module that was malfunctioning and would need replaced. They then explained that the part was "restricted" by Stellantis/Ram, and was not something they could just order. That they would have to create a "STAR" case with Stellantis and get the part authorized/sent directly from Stellantis. I was also told that they would not receive any updates or communication back on STAR cases and that the part would just show up whenever it shows up, and they would let me know. Was told to drive the truck until the part came in, as they did not have any loaner vehicles available. From some online groups I am in for this series of truck, I found a couple other people with the same problem, who reported that the restricted control module is on backorder from STAR/Stellantis until at least mid-January.