Definition
Selective Catalytic Reduction; an aftertreatment process that uses DEF to reduce NOx emissions.
Why It Matters
SCR can appear in fault-code descriptions, scan-tool displays, service information, or driver-facing warning messages. Understanding the term helps you record better diagnostic context.
What To Record
Record the full code, related warning lamps, active or inactive status, vehicle system, and operating conditions.
Diagnosis Note
Glossary definitions are educational. Final diagnosis should use official service information and qualified diagnostic tools.
Related Pages
Sources
- SAE J1939 Standards Collection SAE International · official · accessed 2026-05-05 · confidence medium
Source: SAE International, SAE J1939 Standards Collection. This page paraphrases factual fields only and is not a substitute for the original document.
Open source
FAQ
Is SCR a fault code by itself?
Not usually. It is a diagnostic term that needs context from a full code or system message.
Can SCR have different meanings by OEM?
Some terms are broadly used, but OEM displays and diagnostic procedures can vary.
Does this glossary replace service information?
No. It is an educational reference only.