Injectors

P0204 Fault in the cylinder 4 injector wiring

By: Diagno editorial team · Updated: 2026-10-15

P0204 means: Fault in the cylinder 4 injector wiring. The injector sprays fuel into the cylinder. Drive gently and have the car checked soon. The most common repair costs about €200–400 in Estonia, depending on make and model. The most common cause: injector connector is loose or corroded.

Is it safe to drive?Get it checked soonDrive gently and have the car checked soon.

Injector replacement€200–400parts and labour in Estonia, depending on make and model

What it means

The injector sprays fuel into the cylinder. The engine computer can't control the injector properly. The fault is usually electrical.

What could be wrong

1Injector connector is loose or corroded · Injector replacement €200–400
2Wire is broken · Wiring or connector repair €45–90
3Injector coil has failed · Injector replacement €200–400
4Rarely, the engine computer · Control unit check and software €150–300

What you can check yourself

Check the injector connector. If the engine runs rough, don't drive far. Best left to a workshop. It needs a diagnostic tool and experience.

How we fix it

We measure injector resistance and wiring
We repair the wire or connector
We replace and code the injector

Standard SAE description: Injector Circuit Malfunction - Cylinder 4

This code usually comes with: Check engine lightSee what the light means →

Want a definite answer?

Bring the car to our workshop in Estonia for diagnostics. We read the fault codes, test the sensors and tell you what is wrong. Repair price depends on the work involved, generally €45 per hour.

Book a diagnostic check

Questions

What does fault code P0204 mean?

Fault in the cylinder 4 injector wiring. The injector sprays fuel into the cylinder. The engine computer can't control the injector properly. The fault is usually electrical.

Can I drive with code P0204?

Drive gently and have the car checked soon.

How much does it cost to fix P0204?

It depends on the cause: injector replacement €200–400; wiring or connector repair €45–90. Prices include labour at €45/h, depending on make and model.

How is P0204 fixed?

We measure injector resistance and wiring. We repair the wire or connector. We replace and code the injector.

Based on AI combined with our hands-on workshop experience and knowledge. This information is general and prices are approximate (Estonian workshop rates). The same code can mean different things on different cars. Only an inspection of the car gives a definite answer.