Question 1

What does Global SCR fault code SPN 1761 FMI 1 / 18 mean?

Accepted Answer

SPN 1761 FMI 1 / 18: Empty tank warning when full; Machine shutdown; Alarm buzzer. Fix: DEF Tank Level Low / Implausible.

LOGIC: The tank level sensor (float or ultrasonic) is sending a signal that shows zero fluid or is "stuck."

ACTION: 1. Physically check fluid level with a dipstick. 
2. Tap the side of the tank to see if a mechanical float is stuck. 
3. Check the sensor header pins for corrosion.

FIX: Replace the DEF Tank Header (Level Sensor) assembly.

Question 2

What does Global SCR fault code SPN 3031 FMI 2 / 9 mean?

Accepted Answer

SPN 3031 FMI 2 / 9: DEF pump won't engage; Code appears during cold weather; High fuel use. Fix: 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.

Question 3

What does Global SCR fault code SPN 3216 FMI 13 / 20 mean?

Accepted Answer

SPN 3216 FMI 13 / 20: Intermittent Check Engine Light; Sudden derate; Inconsistent emissions data. Fix: Inlet NOx Sensor - Drifted High / Out of Calibration.

LOGIC: The sensor's ceramic element is "poisoned" or aged, causing it to send a signal that doesn't match engine mapping.

ACTION: 1. Inspect sensor wiring for heat damage. 
2. Check for moisture in the sensor control module. 
3. Perform a "NOx Sensor Reset" in the software.

FIX: Replace the Inlet NOx Sensor and its associated control module.

Question 4

What does Global SCR fault code SPN 3361 FMI 31 mean?

Accepted Answer

SPN 3361 FMI 31: Sudden shutdown or 5 MPH limit; No other active codes; Very difficult to clear. Fix: SCR Inducement - General Warning.

LOGIC: This is a "Global" code that signifies the operator has ignored other emissions faults for too long.

ACTION: 1. Find the "Underlying" fault code (Quality, Level, or Efficiency). 
2. Repair that fault first.

FIX: Perform a "Long-Term Adaptation Reset" or "Emissions Trip Reset" via dealer software.

Question 5

What does Global SCR fault code SPN 3364 FMI 2 / 17 mean?

Accepted Answer

SPN 3364 FMI 2 / 17: Engine derate; "DEF Symbol" flashing; Machine may eventually lock into 5 MPH or Idle-only. Fix: DEF Quality / Concentration Low.

LOGIC: The DEF Quality sensor (ultrasonic) detects the urea concentration is outside the 32.5% +/- 1.5% range.

ACTION: 1. Test DEF with a refractometer (Target 32.5%). 
2. Check for "blue" dye or diesel smell in the DEF tank. 
3. Drain and flush tank if contaminated.

FIX: Drain and refill with fresh ISO 22241 certified DEF; replace DEF Quality Sensor if reading stays static.

Question 6

What does Global SCR fault code SPN 4334 FMI 3 / 4 mean?

Accepted Answer

SPN 4334 FMI 3 / 4: Engine derate; DEF system failure; Possible white smoke from exhaust. Fix: DEF Dosing Pressure Sensor - Voltage High/Low.

LOGIC: The internal sensor in the DEF pump or line is seeing pressure outside of the 4–10 bar operating window.

ACTION: 1. Check for kinked DEF lines. 
2. Inspect the DEF pump filter (usually a small screw-in mesh). 
3. Check for frozen DEF in the lines.

FIX: Replace DEF Pump filter or the complete DEF Pump/Dosing Unit.

Question 7

What does Global SCR fault code SPN 4363 FMI 0 / 16 mean?

Accepted Answer

SPN 4363 FMI 0 / 16: Black smoke; Poor engine performance; High exhaust backpressure. Fix: SCR Inlet Temperature High.

LOGIC: Exhaust gas entering the SCR is too hot, risking permanent damage to the catalyst coating.

ACTION: 1. Check for a sticking EGR valve. 
2. Check for "hydrocarbon slip" (unburned fuel) from a bad injector or leaking turbo.

FIX: Repair the engine-side fault (EGR, Injector, or Turbo) that is causing high EGT.

Question 8

What does Global SCR fault code SPN 4364 FMI 18 mean?

Accepted Answer

SPN 4364 FMI 18: Progressive power loss; "Emissions Failure" warning; Excessive DEF consumption. Fix: SCR NOx Conversion Efficiency Low.

LOGIC: The Outlet NOx sensor is seeing too much NOx compared to the Inlet sensor, meaning the catalyst is not working.

ACTION: 1. Check DEF injector for a "crystal" (white rock) buildup. 
2. Verify DEF pump pressure (usually 5–9 bar). 
3. Check for exhaust leaks at the turbo or bellows.

FIX: Clean DEF Injector tip with hot water; replace DEF Pump or SCR Catalyst.

Question 9

What does Global SCR fault code SPN 5246 FMI 15 mean?

Accepted Answer

SPN 5246 FMI 15: Dash says "Derate in 30 Minutes"; Alarm beeping; Yellow/Amber warnings. Fix: SCR Operator Inducement - Low Severity.

LOGIC: The "Timer" has started. The machine is giving the operator a final warning to refill DEF or fix an emissions fault.

ACTION: 1. Refill DEF immediately. 
2. Check for active NOx sensor codes. 
3. Look for "Service" messages on the MMI display.

FIX: Resolve the active emissions fault and restart the engine.

Question 10

What does Global SCR fault code SPN 5394 FMI 5 mean?

Accepted Answer

SPN 5394 FMI 5: "DEF System Error"; No dosing heard; DEF level stays static for days. Fix: DEF Doser (Injector) Valve - Open Circuit.

LOGIC: The ECM detects no electrical continuity to the DEF injector solenoid.

ACTION: 1. Unplug the injector; check for 5–15 Ohms across the pins. 
2. Inspect the harness for rubs on the chassis.

FIX: Replace the DEF Injector (Doser Valve) or repair the wiring harness pigtail.

Global SCR Fault Codes

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Code	System	Symptom	Full fix
SPN 1761 FMI 1 / 18	—	Empty tank warning when full; Machine shutdown; Alarm buzzer.	View fix
SPN 3031 FMI 2 / 9	—	DEF pump won't engage; Code appears during cold weather; High fuel use.	View fix
SPN 3216 FMI 13 / 20	—	Intermittent Check Engine Light; Sudden derate; Inconsistent emissions data.	View fix
SPN 3361 FMI 31	—	Sudden shutdown or 5 MPH limit; No other active codes; Very difficult to clear.	View fix
SPN 3364 FMI 2 / 17	—	Engine derate; "DEF Symbol" flashing; Machine may eventually lock into 5 MPH or Idle-only.	View fix
SPN 4334 FMI 3 / 4	—	Engine derate; DEF system failure; Possible white smoke from exhaust.	View fix
SPN 4363 FMI 0 / 16	—	Black smoke; Poor engine performance; High exhaust backpressure.	View fix
SPN 4364 FMI 18	—	Progressive power loss; "Emissions Failure" warning; Excessive DEF consumption.	View fix
SPN 5246 FMI 15	—	Dash says "Derate in 30 Minutes"; Alarm beeping; Yellow/Amber warnings.	View fix
SPN 5394 FMI 5	—	"DEF System Error"; No dosing heard; DEF level stays static for days.	View fix