A fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.
What you can do yourself
- Only on engines with EGR.
- The control unit calculates how much exhaust gas returns to the intake. Flow below normal — the EGR valve is carboned up or stuck; above normal — the valve doesn’t close.
- Check the valve connector and wiring.
- The EGR valve often gets clogged with carbon — it needs cleaning or replacing.
Stop and don’t drive on if:
- The Check Engine light is flashing
- The temperature gauge is in the red or the overheating light is on
- The red oil pressure light is on
- Smoke from under the bonnet, a burning or petrol smell
- Strong jerking, knocking from the engine, or the car barely moves
Add the FMI — the second number of the code. It shows what exactly is wrong with the parameter.
Source: Navistar IK1200516: MaxxForce DT 9/10 DTC (static.nhtsa.gov, MC-10167665)
The explanation comes from the error code reference in the AvtoElektrik PRO app.