Glossary of Automotive Terms Diesel Exhaust Fluid

Diesel Exhaust Fluid

Created by William Orellana Updated September 24, 2024 Popularity: 83 Views

Diesel Exhaust Fluid (DEF) is a solution used in modern diesel vehicles to reduce harmful emissions produced by the engine. It is a mixture of urea and deionized water that is injected into the exhaust stream to break down harmful nitrogen oxides (NOx) into harmless nitrogen and water vapor. DEF is stored in a separate tank in the vehicle and is automatically sprayed into the exhaust system when needed.

Technical Explanation:

Common Symptoms:

  • Warning light on the dashboard indicating low DEF levels
  • Reduced engine performance or power
  • Increased emissions output

Diagnosing:

  • Checking the DEF tank level to ensure it is not empty
  • Inspecting the DEF system for leaks or malfunctions
  • Using diagnostic tools to check for error codes related to the DEF system

Common Repairs:

  • Refilling the DEF tank with the appropriate fluid
  • Repairing any leaks in the DEF system
  • Replacing faulty DEF injectors or sensors
  • Updating software or recalibrating the DEF system to resolve any issues