Several systems can create the same driver complaint.
A symptom page is not a diagnosis. Vehicle year, make, model, VIN, active faults and operating conditions determine the correct test path.
- DEF quality warning
- DEF system fault
- SCR efficiency fault
- NOx sensor code
- Inducement or countdown warning
Capture information before it disappears.
If the vehicle is safe to do so, record what happened before cycling the key or clearing faults.
- Photograph warning messages
- Record fault codes if available
- Note speed, load and temperature when it happened
- Tell us whether the problem is constant or intermittent
- Stop operating if a red stop warning or unsafe condition is present
DEF Warning Light on a Truck | Mississauga Diagnostics — answered.
Can you diagnose this without seeing the truck?
We can help determine urgency from the information you provide, but a repair diagnosis generally requires testing the vehicle.
Should I clear the codes before bringing it in?
If possible, avoid clearing codes because stored fault and freeze-frame information can help diagnosis.
What if the truck is unsafe to drive?
Do not continue operating an unsafe commercial vehicle. Arrange appropriate roadside or towing support and contact the shop with the symptoms.
Tell us what the truck is doing.
Have the year, make, model, VIN, mileage, warning lights or fault codes, and whether the truck can be driven safely.
Mr Diesel Inc. · 5900 Dixie Rd, Unit 13, Mississauga ON L4W 1E9