Global SCR Fault Code
Free · no signupSPN 3031 FMI 2 / 9
DEF pump won't engage; Code appears during cold weather; High fuel use.
System
Not specified
Symptom
DEF pump won't engage; Code appears during cold weather; High fuel use.
Diagnosis & fix steps
DEF Tank Temperature Sensor - Data Erratic.
LOGIC: The ECM needs to know if the DEF is frozen (at -11°C) to turn on the heaters. If the sensor signal is erratic, it won't dose DEF.
ACTION: 1. Check resistance of the temp sensor (thermistor).
2. Inspect the DEF coolant heating valve for operation.
FIX: Replace the DEF Tank Header (where the temp sensor is located) or the heating solenoid.
Red Seal field insights
If the machine thinks the DEF is -40°C on a hot day, it won't pump DEF to prevent pump damage. This sensor is integrated into the level sensor header on 90% of machines.
Same code keeps coming back?
That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.
Read before you touch anything
- This is general reference information, not a repair manual. It is for trained, qualified technicians.
- Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
- Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
- You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
- Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.
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Start your free trialRelated Global SCR fault codes
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- SPN 3361 FMI 31Sudden shutdown or 5 MPH limit; No other active codes; Very difficult to clear.
- SPN 3364 FMI 2 / 17Engine derate; "DEF Symbol" flashing; Machine may eventually lock into 5 MPH or Idle-only.
- SPN 4334 FMI 3 / 4Engine derate; DEF system failure; Possible white smoke from exhaust.
- SPN 4363 FMI 0 / 16Black smoke; Poor engine performance; High exhaust backpressure.
- SPN 4364 FMI 18Progressive power loss; "Emissions Failure" warning; Excessive DEF consumption.
- SPN 5246 FMI 15Dash says "Derate in 30 Minutes"; Alarm beeping; Yellow/Amber warnings.
- SPN 5394 FMI 5"DEF System Error"; No dosing heard; DEF level stays static for days.