DEF / AdBlue Warning
Engine & Drivetrain
Diesel Exhaust Fluid is low. If not refilled, the vehicle may enter a reduced power mode or refuse to start.
Quick answer
You can drive short distances, but get the vehicle serviced soon to avoid further damage.
DEF / AdBlue Warning on your specific vehicle
Select your make, model, and year for a guide tailored to your car.
Covers Toyota, Honda, Ford, Chevrolet, Nissan, Hyundai, Jeep and popular models 2015–2024.
What does this warning light look like?
The def / adblue warning appears in your instrument cluster or dashboard. It's sometimes described as: diesel, adblue, def, exhaust fluid, blue fluid, diesel fluid.
Commonly searched phrases
People often search for: DEF light on • AdBlue warning • diesel exhaust fluid light • DEF low warning
Common causes
Causes vary by vehicle and driving conditions. A professional diagnostic scan or inspection is the best way to identify the exact cause.
Can I keep driving?
Short distances only. Drive carefully and get serviced soon.
What to do
Refill DEF/AdBlue tank at the nearest opportunity. Available at most gas stations and auto parts stores.
Estimated repair cost
$10–$30 (fluid only)
Exact cost depends on the cause, your vehicle, and labor rates in your area.
Frequently asked questions
- What does the DEF / AdBlue Warning mean?
- Diesel Exhaust Fluid is low. If not refilled, the vehicle may enter a reduced power mode or refuse to start.
- Can I drive with the DEF / AdBlue Warning on?
- Short distances only. Drive carefully and get serviced soon.
- What should I do if I see the DEF / AdBlue Warning?
- Refill DEF/AdBlue tank at the nearest opportunity. Available at most gas stations and auto parts stores.
- How much does it cost to fix the DEF / AdBlue Warning?
- Repair costs typically range from $10–$30 (fluid only). The exact cost depends on the cause and your vehicle.
Other Engine & Drivetrain lights
You might also see these dashboard symbols in the same category: