SPN 3242 — Aftertreatment 1 DPF Intake Gas Temperature
System: Aftertreatment / DPF
Exhaust temperature entering the diesel particulate filter.
Can I keep running it?
MEDIUM — fix soon
Regenerations may be blocked until fixed, leading to soot buildup.
Likely causes
- Failed exhaust temperature sensor
- Wiring damage from heat
- Diesel oxidation catalyst not lighting off
Checks & fixes (easiest first)
- Compare all exhaust temperature sensors at idle after a cold soak
- Inspect wiring for heat damage
- Check DOC performance during a regen
Common FMIs with SPN 3242
- SPN 3242 FMI 0Value too high (most severe)
- SPN 3242 FMI 2Data erratic, intermittent, or incorrect
- SPN 3242 FMI 3Voltage above normal or shorted high
- SPN 3242 FMI 4Voltage below normal or shorted low
- SPN 3242 FMI 16Value too high (moderately severe)
Related codes
FAQ
What does SPN 3242 mean?
SPN 3242 is Aftertreatment 1 DPF Intake Gas Temperature. Exhaust temperature entering the diesel particulate filter.
Can I keep running with SPN 3242?
Regenerations may be blocked until fixed, leading to soot buildup.
What causes SPN 3242?
Failed exhaust temperature sensor; Wiring damage from heat; Diesel oxidation catalyst not lighting off.