DEF & SCR System Repair Jerome, Idaho
DEF and SCR system repair in Jerome, Idaho is the fix behind most modern derates. Bad NOx sensor, DEF pump fault, dosing valve stuck, quality light on — The Semi Shop tests the aftertreatment system the right way and quotes the fix before we start.
What does DEF & SCR repair include?
We cover the whole aftertreatment chain: DEF pumps, DEF injectors and dosing valves, NOx sensors before and after the SCR, DEF quality sensors, heated lines and tank heaters, and the SCR catalyst itself. Using dealer-level software for Cummins, Detroit, PACCAR, and CAT, we run the system tests the engine maker designed instead of guessing.
That matters because DEF codes lie. An "SCR efficiency" code can be a real catalyst problem, or it can be a cheap sensor, contaminated DEF, or a dosing valve that's crusted shut. Testing first means you pay for the part that actually failed.
How long does DEF system repair take?
Diagnosis is usually an hour or two. Many repairs — a NOx sensor, a dosing valve, a DEF line — are same-day jobs when parts are on hand. Bigger jobs like a DEF pump or SCR catalyst take longer, and we give you the timeline with the quote. Open 7 AM to 10 PM, every day.
What to expect: quote first
You get a firm price after diagnosis and before repair. The price we quote is the price you pay. If your truck is derated and can't reach us, we do mobile DEF and SCR work at I-84 exits from Bliss to Declo, with the flat call-out fee stated before we roll.
DEF trouble in Idaho winters
DEF freezes at 12 degrees, and Magic Valley cold snaps go well below that. Trucks are built to thaw it, but tank heaters and heated lines fail, and when they do, the codes and derates follow. If your DEF gauge acts strange on cold mornings or the quality light comes on in January, that's a heater circuit worth testing before it becomes a 5 mph problem on I-84.
Driver questions
Why is my DEF light on when the tank is full?
Usually a sensor or system fault, not the fluid level — a DEF quality sensor, a level sensor, or a dosing fault can all light it up. A scan tells us which. Don't ignore it; DEF faults escalate to derates.
Can bad DEF fluid cause problems?
Yes. Old, diluted, or contaminated DEF sets quality codes and can damage the system. If we suspect the fluid, we test it and drain and refill the tank as part of the repair.
Do you replace NOx sensors?
All the time — they're one of the most common failures on modern trucks. We test first so you're not buying a sensor when the real fault is wiring or the SCR. Quote before we start, always.
Shop bays in Jerome or mobile to any I-84 exit, Bliss to Declo · 7 AM–10 PM every day · The price we quote is the price you pay.