Cylinder 12 Injector A Circuit
What it means
P0212 means the computer detected a fault in the electrical circuit that fires the cylinder 12 fuel injector (found on twelve-cylinder engines). When that circuit fails the injector often stops firing, so cylinder 12 misfires and the engine runs rough and down on power. Because sustained misfires can damage the catalytic converter, it's worth fixing quickly — usually a failed injector or its wiring.
Can I keep driving? Drive as little as possible — an injector circuit fault usually means cylinder 12 isn't firing, causing a misfire that can overheat and damage the catalytic converter.
Common symptoms
What you'll notice
- Check-engine light on (may flash during an active misfire)
- Rough running, shaking, or misfire
- Reduced power and hesitation on acceleration
- Poor fuel economy, possible raw-fuel smell
Common causes
Most likely first
- Failed injector for cylinder 12 (open or shorted coil)Likely
- Open, shorted, or chafed wiring in the cylinder 12 injector circuitCommon
- Corroded or loose injector connectorCommon
- Poor injector driver ground or supplyLess often
- Rarely, an ECM/PCM injector-driver faultLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the misfire is on cylinder 12.
- Inspect the cylinder 12 injector connector and wiring for damage, corrosion, or a loose fit.
- Measure the injector's resistance against spec and compare with the other injectors.
- Check for injector-drive signal and proper power/ground at the connector.
- Replace the injector if it's open or shorted and the wiring is good. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0212?+
Can I just clear P0212?+
Related codes
Often seen with P0212
Read & clear P0212 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.