P0204 — Injector Circuit/Open - Cylinder 4

What it means

The control module has detected an open or an implausible resistance in the electrical circuit of the cylinder 4 injector. The cylinder gets no fuel, the engine runs unevenly, shakes at idle and pulls poorly under load. On a four cylinder engine the loss of one cylinder is clearly felt and the check engine lamp usually comes on together with a misfire code.

Likely causes (most common first)

1. Faulty connector or bent terminal at the cylinder 4 injector
2. Break in the wiring between the control module and the injector
3. Open injector coil, resistance far from the nominal value
4. Blown fuse or relay contact failure in the injector supply
5. Corrosion of the harness ground point of the injector group
6. Damaged injector driver stage inside the engine control module

Can you drive with it?

Not recommended beyond the trip to the workshop: fuel that is not burned washes down the cylinder walls and the catalytic converter overheats.