Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature 1 — Voltage Below Normal or Shorted Low
The DD-3031-4 (Detroit Diesel DD Series) diesel fault code means: Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature 1 — Voltage Below Normal or Shorted Low. This is a moderate severity code.
This is a standard J1939 fault, not a proprietary code. DD-3031-4 is how this equipment displays SPN 3031 with FMI 4 (voltage below normal or shorted low) under the SAE J1939 standard used across heavy equipment. The same SPN can appear on any J1939-compliant machine regardless of brand — so cross-referencing it against your engine maker's documentation is valid even when the equipment brand differs.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- intermediate
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What Are the Symptoms of DD-3031-4?
- Check Engine or an aftertreatment warning light
- The Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature 1 signal pegged high or low; the controller may substitute a default value
What Causes DD-3031-4? (Most Likely First)
- Open, shorted or chafed wiring in the sensor circuit High
- Failed sensor High
- Loss of the sensor reference or ground Medium
Can I Still Drive with DD-3031-4?
Yes, but fix soon. DD-3031-4 is rated moderate severity. It is not an immediate stop-driving fault, but it will not clear itself — book the repair rather than ignoring it.
Frequently Asked Questions
What does SPN 3031 FMI 4 mean?
SPN 3031 is "Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature 1" in the SAE J1939 Digital Annex, and FMI 4 means the sensor or actuator circuit is reading low voltage. Together they say the sensor or actuator circuit is reading low voltage for that parameter.
Is this a Detroit Diesel-specific code?
No. It is a standard J1939 SPN and FMI pair, so the parameter and failure mode mean the same on any J1939 engine. What Detroit Diesel checks before setting it, and what the truck does about it, is in Detroit Diesel service information.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose DD-3031-4?
Check reference voltage, ground and signal at the sensor connector.
Check the signal wire for a short to voltage or ground back to the controller.
Inspect the connector for corrosion or damage.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SPN 3031 record in the ISOBUS Data Dictionary (ISO 11783 online database), reproducing the SAE heavy-duty Digital Annex (DA) name "Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature 1". Establishes what the SPN names, not what a Detroit Diesel display shows for it.ISO 11783 online database copy of the SAE J1939 Digital Annex SPN list — readable, not SAE’s current edition
- SAE J1939-73Application Layer: Diagnostics (defines the SPN/FMI fault-identifier framework)
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