P0212 OBD-II Trouble Code: Injector Circuit Malfunction - Cylinder 12

P0212 code definition

Injector Circuit Malfunction - Cylinder 12

What the P212 code means

• P0212 is telling us the Engine Control Module (ECM) has detected a fault within the cylinder 12 fuel injector circuit. This code is specifically set when either the voltage or resistance is found to be out of range.

• This code is similar to and may be seen in conjunction with P0200 - P0211, which are all fuel injector codes.

• Misfire, lean condition, and rich condition codes can be seen alongside injector issues.

What causes the P0212 code?

• ECM is failing or has failed
• Open or shorted wiring harness
• Electrical connection that is broken or poor
• Fuel injector cylinder 12 needs replacement

What are the symptoms of the P0212 code?

• The Check Engine Light is observed on the dashboard after the fault is detected by the ECM

• A failsafe mode, which is a precaution to prevent damage to the vehicle, is enacted by the ECM

• Failsafe mode remains in effect until the circuit has performance that is within range or the fault is repaired

Symptoms that are felt just before the Check Engine Light is set include:

• Car runs poorly
• Engine struggles to run and dies
• Car is hard to restart
• Poor fuel milage
• Lean, rich, or misfire conditions

How does a mechanic diagnose the P0212 code?

• Checks the ECM for any codes that are stored and looks at the freeze frame data for each

• Clears the codes and test drives the vehicle to verify the issues

If the issue is verified:

• Uses the scan tool again to monitor operation of the injector circuit

• Checks the voltage with a multimeter at the injector itself; a noid light may be used to check the pulse width.

If all else fails, the ECM will need to be tested to the manufacturer's specifications.

Common mistakes when diagnosing the P0212 code

Mistakes can be made when steps are not all followed or if steps are skipped entirely. Though the fuel injector is the most common cause, it and all other components must be tested before anything is replaced

How serious is the P0212 code?

P02012 can be rather serious depending on the symptoms. Things like a misfire or rich condition can be mild. On the other hand, symptoms can be rather serious, such as an engine that dies while running or is hard to start.

What repairs can fix the P0212 code?

• Replacing the ECM
• Replacing the fuel injector for cylinder 12
• Repairing or replacing an open or short in the wiring harness
• Repairing electrical connection issues

Additional comments for consideration regarding the P0212 code

In some cases, a noid light may need to be used to check the voltage pulse width of the fuel injector. This is done to see the pulse coming from the ECM; the noid light will light up telling the technician if the injector is within specifications.

Professionals will use advanced scan tools that have the ability to view live data and changes in time that are very helpful, especially for intermittent issues.

Vehicles over 100k miles sometimes have an accumulation of varnish that is a buildup of particles in gasoline. Sometimes these can build up to the point where they clog injectors and other fuel components. Seafoam can be used to repair fuel injectors by unclogging them, in certain scenarios.

Need help with a P0212 code?

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