Exhaust Aftertreatment System A Leak
The ECM detects a leak in exhaust aftertreatment system A. Pressure or temperature signals indicate gas escape between aftertreatment components, impairing emission control.
Affected components
- Exhaust aftertreatment system a
- Exhaust seals
Common causes
- High likelihood: Aftertreatment seal aged or cracked
- Medium likelihood: Aftertreatment fitting loose
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
- Reduced-power or limp mode may occur
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.