Detailed guide for SPN 3242 FMI 15
Back to top ↑SCR needs heat. If the system sees outlet temps too low, dosing and conversion suffer.\n\nWinter + light loads make this show up a lot.
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Share ↓SPN 3242 FMI 15Severity: Warning
SPN 3242 FMI 15: Aftertreatment 1 outlet temperature too low during dosing
Quick Answer
Aftertreatment 1 outlet temperature too low during dosing
Code
SPN 3242 FMI 15
Severity
Warning
Applies to
Check OEM application
Can I drive?
Driving suitability is not established by this code alone.
Common Symptoms
- SCR efficiency drops
- Regen or dosing strategy issues
- Inducement can occur if persistent
Likely Causes
- Cold exhaust (winter, low load)
- Faulty temp sensor reading low
- Exhaust leak bleeding heat
Common Fixes
- Check for leaks upstream of SCR
- Verify EGT sensor accuracy
- Operate truck to maintain proper exhaust temps
Full technical sections↓
What does SPN 3242 FMI 15 mean?
Back to top ↑Aftertreatment 1 outlet temperature too low during dosing
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