SPN 3031 — Aftertreatment 1 DEF Tank Temperature
System: Aftertreatment / DEF
Temperature of the DEF in the tank, read by a sensor in the tank header. It controls tank heating and tells the computer whether the fluid can be pumped.
Can I keep running it?
MEDIUM — fix soon
A bad reading can block DEF heating or dosing and lead to inducement derates, especially in cold weather.
Likely causes
- Failed temperature sensor in the tank header (often combined with level/quality)
- DEF-corroded connector or wiring
- Tank heater fault making the reading implausible
- Network message missing from a smart tank sensor
Checks & fixes (easiest first)
- Compare the reading with ambient temperature after a cold soak
- Inspect the header connector for white crust and corrosion
- Check for related heater, level and quality codes
- Check for network codes if the sensor reports over CAN
Common FMIs with SPN 3031
- SPN 3031 FMI 2Data erratic, intermittent, or incorrect
- SPN 3031 FMI 3Voltage above normal or shorted high
- SPN 3031 FMI 4Voltage below normal or shorted low
- SPN 3031 FMI 9Abnormal update rate
- SPN 3031 FMI 16Value too high (moderately severe)
Related codes
- SPN 3363Aftertreatment 1 DEF Tank Heater
- SPN 1761Aftertreatment 1 DEF Tank Volume
- SPN 3364Aftertreatment 1 DEF Quality
FAQ
What does SPN 3031 mean?
SPN 3031 is Aftertreatment 1 DEF Tank Temperature. Temperature of the DEF in the tank, read by a sensor in the tank header. It controls tank heating and tells the computer whether the fluid can be pumped.
Can I keep running with SPN 3031?
A bad reading can block DEF heating or dosing and lead to inducement derates, especially in cold weather.
What causes SPN 3031?
Failed temperature sensor in the tank header (often combined with level/quality); DEF-corroded connector or wiring; Tank heater fault making the reading implausible; Network message missing from a smart tank sensor.