Cummins fault code 4573
DEF Average Consumption: reading below normal (moderately severe)
What it means
Cummins' description: Aftertreatment 1 Diesel Exhaust Fluid Average Consumption - Data Valid But Below Normal Operating Range.
SPN 3826 is Aftertreatment 1 Diesel Exhaust Fluid Average Consumption. FMI 18 means the value is clearly below normal operating range. It's the middle 'low' level.
DEF is sprayed into the exhaust ahead of the SCR catalyst to break down NOx. The system includes the tank, level and temperature sensors, a quality sensor, heaters for cold weather, a pump or dosing unit, lines and the doser.
What the lamp means
An amber (yellow) warning lamp means the engine can usually keep running, but the fault should be repaired soon, ideally the same day.
Green, yellow, red: three ways this can look
The same code can be a quick fix or a reason to shut down. Match your situation to the closest example.
Keep an eye on it
The DEF level warning is on and the truck runs normally. Topping off with fresh DEF clears it.
Schedule a repair
Amber lamp or a DEF quality or dosing code that comes back after filling. Get it checked soon. If left alone, the system will start counting down toward a derate.
Stop and get help
Blinking lamp with a derate countdown, or the truck is already limited to low speed. That's an EPA inducement. It won't fix itself and it can leave a truck stuck at 5 mph.
Common causes
The sensor reading itself is out of range or the condition is real, so look at the system:
- DEF tank low or empty
- Contaminated, diluted or old DEF (water, coolant, diesel, or DEF older than about a year)
- Crystallized DEF clogging the doser, lines or filter
- Weak pump or blocked DEF filter
- Frozen DEF with a heater not working
What you can check before calling
- Check the DEF level and top off with fresh, sealed DEF
- Look for white crystal buildup around the doser, lines and tank
- If DEF was recently added, think about whether it could have been mixed with water or something else
- Note whether the code shows up only in cold weather
Clearing the code without fixing the cause usually brings it right back, and on emissions systems it can restart derate timers. For the bigger picture, read our guide: DEF warning lights and derate: what diesel drivers need to know.
Engines and sources
Cummins uses the same fault code numbers across its electronic engines, including on-highway models like the ISB/B6.7, ISL/L9 and ISX/X15, though not every code applies to every engine or software level. Source: Cummins Tier 4 Fault Codes. Always confirm with Cummins service information (QuickServe) for your engine serial number.
Related DEF codes
- 4572 SPN 3031 FMI 9
DEF Tank Temperature: abnormal update rate - 4488 SPN 5841 FMI 31
DEF Quality Malfunction: condition exists - 4487 SPN 5840 FMI 31
DEF Dosing Malfunction: condition exists - 4486 SPN 5839 FMI 31
DEF Consumption Malfunction: condition exists - 4677 SPN 1761 FMI 9
SAE J1939 Multiplexing PGN Timeout Error: abnormal update rate - 4679 SPN 1761 FMI 5
DEF Tank Level Sensor Circuit: circuit open / current low
Look up another code
Cummins fault code (like 1922), J1939 SPN and FMI (like SPN 3251 FMI 0), or an OBD-II code (like P0420).
Questions
What does Cummins fault code 4573 mean?
Cummins fault code 4573 is J1939 SPN 3826 FMI 18: Aftertreatment 1 Diesel Exhaust Fluid Average Consumption - Data Valid But Below Normal Operating Range. In plain terms: def average consumption: reading below normal (moderately severe).
Can I keep driving with Cummins code 4573?
Usually for a short time, if the engine runs normally and no other warnings are on. Get it diagnosed soon, because many amber codes lead to a derate if ignored. Look at the green, yellow and red examples on this page to judge your situation.
What is the SPN and FMI for Cummins code 4573?
SPN 3826 identifies the part or system (Aftertreatment 1 Diesel Exhaust Fluid Average Consumption). FMI 18 describes the type of failure: reading below normal (moderately severe).
What usually causes Cummins code 4573?
The most common causes are: dEF tank low or empty; contaminated, diluted or old DEF (water, coolant, diesel, or DEF older than about a year); crystallized DEF clogging the doser, lines or filter.
Diesel down in the Midlands?
We work on Cummins-powered pickups, vans and medium-duty trucks across Lexington, Columbia and the Midlands, on site at your yard or roadside.