P046C on RAM: How to Diagnose & Fix
Exhaust Gas Recirculation Sensor "A" Circuit Range/Performance
1 RAM model · 1 documented issue · 1 critical · $500-$1,800 repair
P046C on RAM by model: symptoms, diagnosis and fix
The EGR cooler routes hot exhaust through a coolant-jacketed heat exchanger before recirculating it into the intake. Heavy soot loading progressively plugs the cooler and EGR valve, first showing as slight off-idle hesitation and rising EGTs, then triggering EGR flow/performance codes and limp mode. Worse, a clogged, thermally stressed cooler can crack internally and leak coolant into the exhaust/intake stream, causing white smoke, coolant loss, and potential hydrolock or catastrophic engine damage. Cummins service intervals call for cleaning the EGR valve/cooler roughly every 67,500 miles (2007.5-2018) or 75,000 miles (2019+), which many owners never perform.
Common Symptoms
- Hesitation off idle
- Rising exhaust gas temperatures under load
- White exhaust smoke / sweet coolant smell
- Unexplained coolant loss
- Check engine light with EGR flow codes
- Reduced power / limp mode
How to Fix
Clean or replace the EGR cooler and valve. Genuine replacement cooler OEM PNs include 68048988AA (and related 4988885 / 4988884 / 68048991AA / 68444764AA for later trucks); an upgraded H-core cooler (e.g., BulletProof Diesel) resists cracking and clogging better than stock. Replace the EGR valve if the pintle is coked. Keep the DPF/regen system healthy, avoid excessive short-trip idling, and inspect/clean on Cummins' recommended interval to prevent the crack-and-coolant-loss failure mode.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Bullet Proof Diesel 6700121 H-Core EGR cooler
Confirm connection style and return-core terms.
- Bullet Proof Diesel 6700120 H-Core EGR cooler
Confirm existing cooler and connector style.
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Sources for this issue (3)
P046C code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P046C mean on a RAM?
P046C stands for "Exhaust Gas Recirculation Sensor "A" Circuit Range/Performance." This code means the engine computer found that the signal from the exhaust gas recirculation (EGR) position/flow sensor is out of its expected range or not changing the way it should compared with commands. The EGR system routes a measured amount of exhaust back into the intake to lower combustion temperatures and reduce emissions, and this sensor reports how far the valve is open or how much gas is flowing. An implausible reading suggests the sensor, the valve it monitors, or the wiring is not performing correctly, which can affect emissions and sometimes idle quality. On RAM it is documented across 1 model: 2500.
What are the most common causes of P046C?
The most common causes of P046C are: Faulty EGR position or flow sensor, Carbon buildup clogging the EGR valve or passages, Sticking or failing EGR valve, Damaged, corroded, or loose sensor wiring/connector, Bent or pushed-out connector terminals, Vacuum or exhaust leak affecting EGR flow, PCM fault (rare). The specific cause varies by vehicle.
How much does it cost to fix P046C on a RAM?
Published repair estimates on RAM range from $500 to $1,800 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P046C on a different make?
View P046C across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.