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
- Replace the fuel filters, check the lift pump and air in the system.
- FMI 1, 17, 18 — pressure lower than required: fuel filters, the lift pump, air in the system, leaks, a worn high-pressure pump or injector leak-off.
- FMI 0, 15, 16 — pressure higher than required: the high-pressure pump regulator (metering valve) or the rail pressure relief valve.
- FMI 2, 3, 4 — the rail pressure sensor, its connector or wiring.
- Compare the pressure with the norm on the “Sensors” tab.
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 IK1500109: A26 Fuel System Diagnostics (static.nhtsa.gov, MC-11029476)
The explanation comes from the error code reference in the AvtoElektrik PRO app.