What's involved
What this repair actually is.
Diesel emissions systems inject DEF fluid to neutralize NOx, and faults in the DEF pump, injector, heater, level sensor, or quality sensor trigger warnings that legally force the vehicle into severely reduced speed if ignored. We scan the SCR system, test DEF quality and dosing, and check the heaters and sensors to identify the failed component before the countdown runs out.
Symptoms
How you can tell.
- DEF or SCR warning message on the dash
- Speed-limit countdown warning
- DEF gauge reads wrong or empty when full
- Check engine light with NOx or SCR codes
- Crystallized white residue around the DEF tank
If you delay
Federal emissions rules force the vehicle into a 5-mph limp mode when the DEF countdown expires — it will not clear until repaired.
Educational estimate. Real pricing depends on your vehicle, the inspection, parts availability, taxes, and shop rates. Use this as a guide while you shop quotes.