2025-2026 Ram HD Known Issues: Recalls, TSBs and Fixes

The Morning My Dash Lit Up Like a Christmas Tree

There’s a specific kind of dread that comes with a diesel truck dash full of amber lights. It happened to a 2026 Ram 3500 owner in April 2026, and his description to NHTSA is worth reading exactly as written:

“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.”

He wasn’t done. That same owner filed again on the same day for a second event, and then a third — a third visit to the dealership for the same code. Towed on January 19. Driven in on March 26. Towed again after the truck wouldn’t go into gear and wouldn’t shut off.

That story is complaint ODI 11732293, and it’s one of the reasons this article exists. If you’re shopping a 2025 or 2026 Ram 2500/3500, or you already own one, you deserve a straight answer about which problems are real, which are documented by the federal government, and which are just forum noise. So I did the homework: I pulled the actual NHTSA recall records and the owner complaint database for these model years, then cross-checked the technical details against repair-industry sources.

Here’s what’s actually going on.

The Warning-Light Problem Nobody Warns You About

If you remember one thing from this guide, remember this: the single most reported issue on 2025-2026 Ram HD trucks is a cluster of simultaneous warning lights caused by a rear wheel speed sensor.

It’s not one light. It’s all of them at once:

• ABS
• Electronic Stability Control (ESC)
• Traction control
• 4WD / 4x4
• Cruise control
• Automatic Emergency Braking (AEB)
• Forward collision warning
• And finally, the check engine light

And then the part that turns an annoyance into a safety event: the truck may refuse to shut off, refuse to shift, or refuse to tell you what gear it’s in.

One owner described being stuck in place with the engine running — unable to shift, unable to turn the truck off, unable to drive. Another reported the failures returned after the dealer replaced the sensors. A third logged three separate speed sensor failures in 10,000 miles across eight months.

Is this a handful of unlucky owners? The federal data says no. When I pulled the NHTSA complaint database for the 2025 and 2026 Ram 3500 with the 6.7L Cummins, the diagnostic trouble code U1412 appeared in six separate complaints, and rear wheel speed sensor language appeared in thirteen. Multiple owners specifically named one configuration.

That configuration matters, so let’s talk about it.

Why This Hits Dually Trucks: The 12-Inch AAM Axle

The Ram 3500 uses two different rear axles depending on how the truck is built:

Multiple complaint filers used nearly identical language — a strong sign that owners were sharing information and seeing the same pattern:

“The 2025 and 2026 dually 3500 Ram trucks with the 12-inch AAM rear axle are having issues with the rear wheel speed sensors (different sensor for each side). They apparently fail or are not able to properly communicate to the computer. When this happens, the following are disabled: ABS, Auto Emergency Braking, 4x4, Electronic Stability Control, Cruise.”

The technical failure is simple once you see it. The truck’s computer needs a clean, continuous wheel speed signal to run ABS, stability control, and 4WD logic. When that signal drops or turns erratic, the system doesn’t just lose ABS — it deliberately disables everything that depends on knowing wheel speed, because a wrong decision is worse than no decision. That cascade is why you get a dashboard full of lights from one bad sensor.

The diagnostic codes to know:

• U1412 — the code owners keep reporting
• C0037-2F — Left Rear Wheel Speed Sensor, signal erratic
• C003A-2F — Right Rear Wheel Speed Sensor, signal erratic

And here’s the part that surprises people: this isn’t a brand-new problem for Ram. A technical service bulletin, TSB 05-004-24, was issued covering 2019-2024 trucks with the same class of wheel speed sensor issue. Ram has since released a revised sensor — technicians and owners refer to it as the “AB” revision — specifically for the newer trucks.

Which raises the obvious question: does the revised part fix it?

Not always. One owner’s report is blunt about it:

“Despite Stellantis releasing a new revision of wheel speed sensors (AB revision), they have failed in less than 2,000 miles on my truck.”

So: revised part helps, but this is an active issue, not a closed one. If your truck is throwing U1412, you want the latest revision installed and you want the underlying connector and harness inspected — a corroded or loose connector can mimic a failed sensor, and that’s a cheaper fix than replacing sensors over and over.

The Official Recall List: What NHTSA Actually Documents

This is the part I’d want if I were buying. Rather than guess which problems are “real,” I pulled the actual recall records. Every line below is a government record with a campaign number, not an owner’s opinion.

Two observations from reading all nine:

First, the cluster problem is a pattern, not a fluke. Four separate recalls (25V530000, 25V826000, 26V225000, plus the 25V297000 display accuracy recall) all touch the instrument panel or its software. If you own one of these trucks and your screen has gone blank or shown a warning that didn’t make sense, you are not imagining it.

Second, the trailer tow module recall is the one that should worry towers most. FCA campaign 03D covers a defect where your trailer lights may fail to illuminate and your trailer brakes may fail to apply. If you tow heavy, that is the recall to get done first. Some owners have reported dealers waiting on parts — which is worth knowing before you plan a big trip.

How to check your own VIN: every one of these is free to fix, and none of them expire based on mileage. Go to nhtsa.gov/recalls, enter your 17-digit VIN, and you’ll get the list that applies to your exact truck. Do this before you buy, too — a dealer can’t sell around a safety recall, but a private seller can absolutely forget to tell you.

The Other Known Issues (Owner-Reported, Documented, Not Recalled)

Beyond the recalls, three more issues show up repeatedly in complaint data and in repair-industry analyses. These aren’t recalled — but they’re real enough that you should know about them.

1. U-Connect screen going black. One verified complaint describes the 12-inch U-Connect system going completely black and inoperable until reset. The safety angle is real: the trailer brake gain control and exhaust brake are accessed through that screen on some configurations. If it’s black, you can’t reach them. A reset takes two to three minutes, which is a long time while towing.

2. DEF gauge erratic readings and unexpected derate. Multiple sources — including a lemon-law firm that reviewed NHTSA data — flag the DEF gauge fluctuating between full, half, and empty, sometimes triggering a countdown to limp mode shortly after a refill. The fault codes in this family are P20EE, P207F, P203F, P20E9 and related SCR codes. The fix range is wide because the cause ranges from bad DEF to a failed NOx sensor to a failed tank heater.

3. Exhaust Gas Temperature (EGT) module failures. Reported “Service Exhaust System” warnings accompanied by fuel economy drops, with parts backorders stretching repair times. This is the classic case of a sensor problem masquerading as a major mechanical failure — which is exactly why step one below is “scan it before you panic.”

One thing worth flagging for anyone who’s been reading about older 6.7 trucks: the 2025-2026 engine is not the same engine. The high-pressure fuel pump changed again for this generation (owners and techs describe it as the CP8, replacing the CP4.2 that lived in the 2019-2020 trucks), the intake manifold moved to a bolt-on aluminum design, and the engine went back to glow plugs instead of the grid heater that had its own well-publicized bolt-drop reputation. In plain terms: the powertrain is genuinely new, so older forum posts about earlier 6.7s don’t always apply to your truck.

What to Do When the Dash Lights Up

This is where most owners lose money, so let’s be orderly about it.

Step 1: Photograph everything before you do anything

Take a photo of the full cluster with all warning lights lit, and a photo of the odometer with the miles visible. If the truck is doing the “won’t shut off, won’t shift” trick, that photo is your evidence. Intermittent electrical faults are notorious for disappearing at the dealership, and “they couldn’t reproduce it” has stranded a lot of owners outside warranty.

Step 2: Pull the code yourself

Any capable OBD-II scanner will read the trouble code. You’re looking for U1412, C0037-2F, or C003A-2F if it’s the wheel speed issue. Knowing the code before you walk into a service bay changes the entire conversation.

Step 3: Check recalls first, diagnosis second

Run your VIN at nhtsa.gov/recalls before you authorize a single dollar of diagnosis. If the symptom you’re seeing matches an open recall — blank cluster, trailer lights, brake warning — the repair is free and you shouldn’t pay for anything.

Step 4: Fix the cheap thing before the expensive thing

For the wheel speed issue, the progression should be: inspect and reseat the connector, check the harness for chafing or corrosion, and only then replace the sensor. A sensor is cheap. Replacing four sensors because nobody checked a $2 connector is what makes people angry.

Step 5: Drive it weekly if you’re storing it

Several of the DEF and emissions complaints trace back to trucks that sit. The SCR system wants to reach operating temperature and run a complete cycle. Short trips and long storage are what let DEF crystallize and sensors drift.

Five Expensive Mistakes

Mistake #1: Paying for a repair that’s covered by a recall

If your instrument panel went blank on a 2025-2026 Ram HD, that is a recall — 25V826000 or 26V225000. If your trailer lights or trailer brakes failed, that’s 26V059000. Owners have paid out of pocket for problems that Ram fixes free. Check the VIN first. Every time.

Mistake #2: Believing “they couldn’t reproduce it” is the end of the conversation

Intermittent faults are the norm here, not the exception. If the dealer can’t reproduce it, that doesn’t mean the problem isn’t real — it means you didn’t bring evidence. Photos, dates, and a documented pattern change the outcome.

Mistake #3: Throwing sensors at a wiring problem

The U1412 pattern includes owners on their third set of speed sensors. If the sensors keep failing in the same place, the fault is very likely in the harness, the connector, or the signal path — not the part. Diagnose the circuit, not just the code.

Mistake #4: Assuming older 6.7 advice applies to a 2025-2026 truck

This generation changed the fuel pump, the intake manifold, and the cold-start hardware. Advice, parts, and “known fix” write-ups written for a 2019 truck can send you down the wrong path entirely. Match the advice to the model year.

Mistake #5: Letting electrical frustration distract you from the maintenance that actually protects the engine

Here’s the honest irony. The electrical gremlins are what generate the headlines and the service visits — but the thing that quietly kills a modern 6.7 is contaminated fuel reaching the high-pressure pump. The fuel filter is the only barrier between your tank and a very expensive pump. If you’re spending weekends at the dealership chasing warning lights, don’t let the fuel and oil service intervals slide. Those are the maintenance items that decide whether the truck is still on the road at 300,000 miles.

Frequently Asked Questions

What are the most common problems on a 2025-2026 Ram 2500/3500?

The most reported issue is a cluster of simultaneous warning lights — ABS, ESC, traction control, 4WD, cruise, and check engine — traced to a rear wheel speed sensor, particularly on dually trucks with the 12-inch AAM rear axle. Beyond that, instrument cluster display failures, the trailer tow module defect, erratic DEF gauge behavior, and EGT module failures round out the list.

Is there a recall on the 2025-2026 Ram HD instrument cluster?

Yes — more than one. Recall 25V826000 (December 2025) covers a blank instrument cluster display, and 26V225000 (April 2026, FCA 35D) covers complete display failure. Recall 25V530000 covers an incorrect brake warning light. All are fixed free by a dealer software update or cluster replacement.

What is code U1412 on a Ram 3500?

U1412 is the code owners most often report alongside the warning-light cascade. It’s associated with the anti-lock brake system and points toward the rear wheel speed sensor circuit. Related circuit codes are C0037-2F (left rear) and C003A-2F (right rear).

Which trucks are affected by the wheel speed sensor issue?

Reports concentrate on 2025 and 2026 Ram 3500 dually trucks equipped with the 12-inch AAM rear axle. A technical service bulletin, TSB 05-004-24, addressed the same class of issue on 2019-2024 trucks, and Ram has released an “AB” revision sensor for the newer models.

Does the revised “AB” wheel speed sensor fix the problem permanently?

Not for everyone. There are documented cases of the revised sensor failing in under 2,000 miles. The revised part is the right first step, but if failures repeat in the same location, the wiring harness and connector should be inspected as the likely root cause.

What happens if I ignore the warning lights?

You lose ABS, electronic stability control, traction control, 4WD, and automatic emergency braking — and on some trucks you can lose the ability to shift or shut the engine off. On a truck that tows, that’s a safety issue, not a cosmetic one.

What is recall 26V059000 about?

It covers an improperly designed trailer tow module on 2025-2026 Ram HD and other vehicles, where trailer lights may fail to illuminate and trailer brakes may fail to apply. Dealers replace the module free of charge. FCA’s internal number for this recall is 03D.

My DEF gauge jumps between full and empty. Is that normal?

No, and it’s worth taking seriously. Erratic DEF level readings appear repeatedly in owner complaints and can precede an unexpected derate or limp-mode countdown. It’s usually related to the tank level sensor, a NOx sensor, or DEF quality rather than a mechanical engine failure — but diagnose it before it strands you.

Should I buy a 2025-2026 Ram HD knowing about these issues?

Every new platform has a first-year list, and this one is unusually well documented — which is actually useful. The recalls are free and the fixes are known. What you should do is verify the recalls are complete on any truck you’re considering, check the service history, and budget for the wheel speed sensor circuit to be inspected rather than replaced blindly.

How much does a wheel speed sensor replacement cost?

On a Ram 3500, independent-shop estimates for a speed sensor replacement commonly land in the low hundreds of dollars including parts and labor, though 6.7L diesel configurations price higher than gas models. If the truck is still under warranty or the fault ties to an open recall, that cost should be zero — so always check coverage first.

Are these problems covered under warranty?

Recalls are fixed free regardless of mileage or ownership, and manufacturer warranties typically cover defects in materials and workmanship. Electrical faults can be argued either way depending on the dealer, which is exactly why documentation matters. Keep records, keep photos, and keep the dates.

How do I check whether my truck has open recalls?

Go to nhtsa.gov/recalls and enter your VIN. You’ll get the list of open campaigns for your exact truck, and you can have the same check run at any Ram dealer. Do it before you buy, and again after any service visit.

Chasing Lights, Not Neglecting Fluid

Here’s the uncomfortable truth about owning one of these trucks: the problems that get the most attention — the warning lights, the blank screen, the sensor that keeps failing — are rarely the ones that actually end a truck’s life. They’re annoying, they’re real, and you should get them fixed. But the systems that decide whether a 6.7 Cummins sees 300,000 miles are boring: the right oil, and clean fuel through a filter that actually filters.

If your 2025-2026 Ram is spending more time at the dealership than on the road, at least make sure the maintenance items you can control are handled. For this generation, that means the top-load oil filter and the dual-stage fuel filters that protect the high-pressure pump.

• 2025-2026 Ram 6.7L Engine Oil Filter (Replaces 68677810AA)
• 2025-2026 Ram 6.7L Primary & Secondary Fuel Filter (Replaces 68677800AA)

Want to compare notes with other owners on what’s failing and what fixed it? These threads are worth reading:

• 2025-2026 6.7L Ram Cummins Engine Oil Filter — Replaces 68677810AA
• 2025-2026 6.7L Ram Primary & Secondary Fuel Filter — Replaces 68677800AA

Legal Disclaimer

This guide is for general informational purposes only and is not a substitute for your vehicle’s factory service manual, an official NHTSA recall notice, or the advice of a qualified diesel technician. Recall information is drawn from public NHTSA records and was current as of September 2026; recalls are added and amended over time, so always verify open campaigns for your specific VIN at nhtsa.gov/recalls before making any decision. Owner complaint details are individual accounts and have not been independently verified. Repair cost figures are typical estimates and vary by region, shop, and configuration. Installation of any aftermarket or replacement part is performed at your own risk; the author and retailer assume no liability for damage, injury, or loss arising from the use of this information or the products referenced.