P0212 critical

Injector Circuit / Open - Cylinder 12

The P0212 code means the vehicle's onboard diagnostic system has detected: Injector Circuit / Open - Cylinder 12. This is a critical severity code.

My Garage →

Keep driving?: No -- stop driving
DIY difficulty: hard
Estimated cost: $200 - $600 (fuel injector $100-$300; labor $150-$400)

Recommended Tool

ANCEL AD310 OBD-II Scanner

Best-selling code reader on Amazon. Reads and clears check engine codes on any 1996+ vehicle. Under $30.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Every Tech Needs This

AstroAI Digital Multimeter

Essential for diagnosing sensor codes, checking voltage, and testing circuits. Under $15 and pays for itself on the first job.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Common Symptoms

Check Engine Light on or flashing
Cylinder 12 misfire causing rough running
Power loss noticeable under acceleration
Engine vibration and shaking
Fuel smell from unburned fuel in exhaust

Probable Causes (Ranked by Likelihood)

Failed fuel injector on cylinder 12 Very High
Open or damaged wire in the injector circuit High
Corroded or disconnected injector connector Moderate
PCM injector driver failure Low
High resistance in injector coil Low

Step-by-Step Diagnostic Procedure

Confirm cylinder 12 misfire with a scan tool.
Measure injector resistance on cylinder 12 (11-17 ohms typical).
Check for injector pulse at the connector using a noid light during cranking.
Inspect wiring and connector for damage, corrosion, or breaks.
Swap the injector with another cylinder to isolate the fault.

Frequently Asked Questions

Can I drive with code P0212?

No. A dead cylinder 12 sends unburned fuel into the exhaust system, which can destroy the catalytic converter. Have the vehicle towed and repaired.

Is cylinder 12 the last cylinder on a V12?

Yes. Cylinder 12 is the final cylinder on V12 engines. These are exclusively found on luxury and high-performance vehicles.

Should I take a V12 to a specialist for P0212?

Yes, V12 engines are complex and require specialized knowledge. A dealer or specialist mechanic familiar with your vehicle brand will have the diagnostic tools and experience to properly repair the injector circuit.