Cummins X15 CM2450 X124B (2018 & Newer) Fault Code: 1673 PID: SPN: 1761 FMI: 1 Aftertreatment 1 Diesel Exhaust Fluid Tank Level- Data Valid But Below Normal Operating Range- Most Severe Level

Circuit Description
The aftertreatment diesel exhaust fluid level sensor is used to monitor the diesel exhaust fluid level inside the diesel exhaust fluid tank.

Component Location
The aftertreatment diesel exhaust fluid tank level sensor is located in the aftertreatment diesel exhaust fluid tank. Location of the tank and level sensor is OEM dependent. Refer to the OEM service manual.

Conditions for Running the Diagnostics
The diagnostic runs continuously when the following conditions are met:

Keyswitch is in the ON position or when the engine is running.
Ambient temperature is above -20°C [-4°F].
Vehicle altitude change is less than 305 m [1000 ft] in 1 hour.
Conditions for Setting the Fault Codes
The diesel exhaust fluid tank was critically low.

Action Taken When the Fault Code is Active
The Diesel Exhaust Fluid Lamp will be flashing.
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
Engine torque will be severely reduced.
Vehicle speed will be limited to 8 km [5 mi] per hour after the engine has been shutdown, 1 hour of engine idle time, or the fuel tank has been refilled.

Conditions for Clearing the Fault Code
To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk
This fault code indicates that the Diesel Exhaust Fluid (DEF) level is critically low and there will be a power loss. Engine power will be reduced automatically. This can be corrected by refilling the DEF tank. Normal engine power will be restored after refilling the DEF tank.

Possible Cause:
1) ECM calibration