What does DEF warning light mean?
diesel exhaust fluid
The DEF (diesel exhaust fluid) light is a driver warning system that lets you know when your DEF tank is nearly empty. This affects truck drivers more than it does drivers of passenger vehicles. Before your DEF tank ends up empty, you will see an alert on your dash in the form of the DEF light.
What happens when truck is low on DEF?
Generally, a warning light will come on when DEF needs to be added soon. If the light is ignored for too long, the vehicle will likely go into a reduced power mode. If the DEF level falls too low, the engine will not start until fluid is added.
What happens if you don’t fill DEF fluid?
If the truck is allowed to run out of DEF the engine’s power is reduced, a solid red warning will be displayed and the vehicle speed will be limited to 5 mph until the DEF tank is refilled.
How long can you drive on low DEF?
Since most current vehicles have greater fuel efficiency than their predecessors, the Low Fuel light isn’t necessarily a death sentence for your drive. In fact, you can still drive anywhere between 30 and 50 miles (at the absolute furthest) in order to find the nearest gas station.
Is it bad to run out of DEF fluid?
If the reservoir is not replenished with DEF and runs low, vehicle speed will be limited, but as soon as DEF is added, the engine will resume normal speed levels. A prudent measure would be to have a top-off gallon jug of DEF available on each piece of equipment with an EPA 2010 engine with an aftertreatment system.
How many miles will 1 gallon of DEF last?
Most DEF tanks require one gallon of DEF for every 50 gallons of diesel fuel, and one gallon will generally last between 300 to 500 miles.
What happens to the Def light when the engine is shut down?
If the engine has been shut down or has idled for one hour after the DEF tank has been run dry, the Stop Engine Light will also be lit along with the flashing DEF Lamp and Check Engine Light. Engine power will continue to be reduced automatically. The vehicle will also be limited to a speed of 5 miles per hour.
What makes the low Def warning light go off?
It can be anything in the DEF system and that light will go off. The ’12 T660 I’m in started this at 20K, and was low only one time. Finally it De-rated and got towed to the KW shop in Nashville. Turned out to be a sensor somewhere in the exhaust system.
What does it mean when your Def light is blinking?
SCENARIO THREE: YOUR DEF LIGHT IS FLASHING/BLINKING, AND THE CHECK ENGINE LIGHT IS ON. A flashing DEF Light combined with a Check Engine Light indicates that the DEF level is critically low and you will derate.
What kind of truck has a low DEF tank?
I’m in a 2012 T700 with 78k on the odometer, so still a new truck. I was making good time down I-20 yesterday morning when a glance at my gauges showed the red light on the DEF tank. Catch is that I had 5-8 of a tank. My dash computer switched over to saying Low DEF and my check engine lamp was on.