2012 freightliner box truck with Cummins engine derating at 5 mph codes 3258 3261 1866 3712

hiaibox

Can you give us more details, what kind of truck, any engine codes.

hiaibox

Always start with engine codes? You can find them on your dashboard

collinsmaven

Hello @ahmad could you please provide me the truck make, model, engine ...

ahmad

it’s 2012 freightliner box truck with cumins engine codes 3258 3261 1866 3712

hiaibox

First things first, inspect after treatment relay & fuses.

hiaibox

then inspect engine air filter, make sure it’s clean, yes dirty engine air filter can cause def issues. we start with the simple inspections then we move up the ladder

hiaibox

next, make sure battery terminals are clean

Miketheman

I have the same issue, what was the problem?