DEF and Regen Problem Repair: What to Do and Who to Call
The All Roadside Assistance answer: A DEF warning or a regen that will not finish can put the truck into derate. Call a diesel mechanic that works on aftertreatment systems, and read them the warning lights and codes.
First steps
- Read the warning lights and any fault codes on the dash.
- Check the DEF level and whether the DEF looks clean.
- If the truck asks for a parked regen and it is safe, follow the steps in your manual.
- Plan the nearest safe stop if the truck starts to lose power.
Why it happens
DEF and regen problems include a clogged DPF, a failed DEF sensor or pump, bad DEF, a stuck EGR valve and wiring faults. Many need a diagnostic tool. Listings that mention DEF, DPF or aftertreatment work are marked on this page.
What to tell the provider
The truck make, model and engine, the warning lights and codes, whether the truck is in derate, and when the last regen ran.
How we pick the providers
All Roadside Assistance is a directory. We do not dispatch trucks or take a share of any job. On each town page we list providers whose listing data matches this problem, closest first, within 30 miles of the town center, or 50 miles when fewer than 3 are closer. You call the business directly. Confirm availability, capability and price on the phone.
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Towns with the most providers
- San Ramon, CA
- Hayward, CA
- Pomona, CA
- San Leandro, CA
- Fullerton, CA
- Anaheim, CA
- Corona, CA
- Ontario, CA
- Walnut Creek, CA
- Redwood City, CA
- San Mateo, CA
- Palmdale, CA
Somewhere else? Use your location or search by town, ZIP, highway or exit.