Injector Circuit / Open - Cylinder 12
What does P0212 mean?
The P0212 code means the vehicle's onboard diagnostic system has detected: Injector Circuit / Open - Cylinder 12. This is a critical severity code.
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
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Confirm cylinder 12 misfire with a scan tool.
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Measure injector resistance on cylinder 12 (11-17 ohms typical).
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Check for injector pulse at the connector using a noid light during cranking.
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Inspect wiring and connector for damage, corrosion, or breaks.
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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.