Truck derated on I-80: what it means and what to check

The engine computer cuts power or speed when it sees an emissions or engine-protection fault. On I-80 that can leave you crawling while traffic passes at 75 mph, so decide quickly whether to exit.

Driver checks

• Note the exact dash message and codes.
• Look at the DEF gauge and think about where you last filled.
• Check for loose or damaged plugs and wiring near the DEF tank and exhaust.
• Consider whether a regen was cut short or the truck idled for hours during a closure.

When to get off and call

If a countdown shows or the truck will not climb past a low speed, take the next exit. Odessa (Exit 263), Elm Creek (Exit 257), Lexington (Exit 237) and Gothenburg (Exit 211) all have places to park. See DEF, DPF and derate repair.