P214D: SCR NOx Catalyst Outlet Temperature Too High During Particulate Filter Regeneration

P214D sets when the temperature behind the SCR catalyst exceeds its limit while the particulate filter is regenerating. It is the only code of this group with public manufacturer evidence. Ram pickups with the 6.7L Cummins use it: bulletin 18-053-14 (2014 Ram 2500/3500) reprograms the PCM partly to prevent unnecessary MIL events from P214D, and STAR case S2625000004 (2025–2026 Ram 3500 to 5500) groups it with exhaust temperature sensor codes such as P242B and P2470–P2472, asks for a check of battery voltage first and stresses identifying each sensor by name. That points to sensor faults and calibration as frequent causes, besides genuine overheating from hydrocarbons burning on the hot SCR during regeneration. P214B is the inlet counterpart.

Symptoms

• Check engine light on
• Regeneration aborted or repeated
• Additional exhaust temperature sensor codes

Most likely causes

• Exhaust temperature sensor behind the SCR faulty, confused with another sensor or affected by low battery voltage
• PCM software requiring an update (Ram 6.7L bulletins)
• Regeneration fuel slipping through and burning on the SCR

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes and the NOx data before and after the SCR catalyst
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Check the sensor's connector and wiring
4. Look for exhaust leaks ahead of the sensor
5. Confirm that the AdBlue/DEF is of good quality
6. Replace the sensor only after ruling out power, ground, and leaks

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P214D means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 1: Air and fuel
• 4D: Specific fault in that system

Frequently asked questions

Can I keep driving with code P214D?

You can usually keep driving in the short term, but get it repaired soon: on many diesels, the warning eventually limits starting or engine power.

What causes code P214D?

The most common causes are: exhaust temperature sensor behind the SCR faulty, confused with another sensor or affected by low battery voltage; pCM software requiring an update (Ram 6.7L bulletins); regeneration fuel slipping through and burning on the SCR.

Related codes

• P214CSCR NOx Catalyst Outlet Temperature Too High
• P214BSCR NOx Catalyst Inlet Temperature Too High During Particulate Filter Regeneration
• P214ASCR NOx Catalyst Inlet Temperature Too High
• P242BExhaust Gas Temperature Sensor Circuit Range/Performance (Bank 1 Sensor 3)
• P2471Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 4)
• P0544Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 1

Sources

• static.nhtsa.gov: MC 10139778 9999
• static.nhtsa.gov: MC 11031238 0001
• patents.google.com: en

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.