P2201 on RAM
NOx Sensor Circuit Range/Performance (Bank 1)
P2201 on RAM vehicles indicates nox sensor circuit range/performance (bank 1). Au7o has documented this code across 1 RAM model — most commonly on 2500. This code means the engine computer detected that the NOx (nitrogen oxides) sensor signal on Bank 1 is out of its expected range or not performing correctly. The NOx sensor measures nitrogen oxide levels in the exhaust, mainly on diesel and lean-burn engines, to manage the emissions/SCR system. An implausible reading means the computer can't accurately monitor or control emissions. While not an immediate driving hazard, it can cause emissions faults, failed inspections, and in some vehicles reduced-power modes if the system can't verify proper operation. Typical repair costs on RAM range from $300 to $3,500, depending on the specific model and root cause.
Common Causes of P2201
- •Faulty NOx sensor
- •Wiring or connector problems at the NOx sensor
- •Exhaust leak near the sensor affecting readings
- •Contaminated or aged sensor element
- •DEF/SCR system performance issues skewing readings
- •NOx sensor control module fault
P2201 on RAM by Model
RAM 2500(1 issue)
- Diesel Exhaust Fluid (DEF) System Failures2013-2025
The 2013+ RAM 2500 6.7L Cummins diesel DEF (Diesel Exhaust Fluid) system is plagued with failures of the DEF heater, DEF pump, DEF injector, NOx sensors, and SCR catalyst. The DEF system is required for emissions compliance, and when it fails, the truck enters a "limp mode" that limits speed to 5 mph after a countdown timer expires. DEF heater failures are most common in cold climates where the fluid freezes and cracks the heater element. TSB 18-018-20 addresses DEF heater and quality sensor issues. The NOx sensors (inlet and outlet) fail frequently at $300-500 each.
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View P2201 across all makes →Frequently Asked Questions
What does P2201 mean on RAM?▼
P2201 stands for "NOx Sensor Circuit Range/Performance (Bank 1)." This code means the engine computer detected that the NOx (nitrogen oxides) sensor signal on Bank 1 is out of its expected range or not performing correctly. The NOx sensor measures nitrogen oxide levels in the exhaust, mainly on diesel and lean-burn engines, to manage the emissions/SCR system. An implausible reading means the computer can't accurately monitor or control emissions. While not an immediate driving hazard, it can cause emissions faults, failed inspections, and in some vehicles reduced-power modes if the system can't verify proper operation. On RAM specifically, this code is documented across 1 model.
What causes P2201 on RAM vehicles?▼
Common causes on RAM: Faulty NOx sensor, Wiring or connector problems at the NOx sensor, Exhaust leak near the sensor affecting readings, Contaminated or aged sensor element, DEF/SCR system performance issues skewing readings. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P2201 on a RAM?▼
Repair costs on RAM range from $300 to $3,500, depending on the specific model and root cause.
Which RAM models have P2201 documented?▼
Au7o has documented P2201 on 1 RAM model: 2500.