P0212 Injector: circuit fault (cylinder 12)

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

P0212 means: Injector: circuit fault (cylinder 12). The injector sprays fuel into the cylinder. Drive gently and have the car checked soon. The most common repair costs about €45–90 in Estonia, depending on make and model. The most common cause: connector loose, damp or corroded.

What it means

The injector sprays fuel into the cylinder. The computer found a fault in the injector control or its fuel quantity. The computer found a fault in the electrical circuit: the part, a wire, a connector or a fuse.

What you may notice

• Engine light on
• The engine runs unevenly
• Less power
• Higher fuel consumption

What could be wrong

1. 1Connector loose, damp or corroded · Wiring or connector repair €45–90
2. 2Wire broken or chafed · Wiring or connector repair €45–90
3. 3Faulty injector · Injector replacement €200–400
4. 4Engine computer fault (rare) · Control unit check and software €150–300

Repair difficulty: Moderate

What you can check yourself

First look at the connector and wiring: anything loose, melted or green with corrosion? Check the injector connectors. If the engine runs badly on one cylinder, don't drive far. Best left to a workshop. It needs a diagnostic tool and experience.

How we fix it

1. We read the fault data on the diagnostic tool and check whether the fault is constant
2. We measure the circuit's supply, ground and signal
3. We repair the wire or replace the connector
4. If the wiring is fine, we replace the injector

Standard SAE description: Injector Circuit Malfunction - Cylinder 12