Applicable Systems
OBD-II
Symptoms
The ignition coil 3 control circuit voltage is lower than expected. Cylinder 3 may misfire.
Possible Causes
- Ignition coil 3 primary winding shorted
- Wiring harness shorted to ground
- Ignition coil connector corroded
- ECM ignition driver failed
- Ignition coil internal fault
Troubleshooting Steps
- Step 1: Connect an OBD-II scan tool and read all stored DTCs and freeze frame data
All DTCs and freeze frame data are retrieved - Step 2: Inspect the related sensor or actuator wiring for damage, corrosion, or loose connections
Wiring and connectors are in good condition - Step 3: Use a digital multimeter to check sensor voltage, resistance, and reference signals per manufacturer specifications
Values are within specified range - Step 4: Perform component-level testing of the suspected sensor or actuator
Component passes or fails definitively - Step 5: Clear codes and road test to verify repair
Code does not return and system operates normally
How to Reset
To reset code P1212: 1) Repair the underlying fault. 2) Use an OBD-II scan tool to clear the DTC. 3) Perform a drive cycle to verify the monitor completes. 4) If the code returns, further diagnosis is needed.
Frequently Asked Questions
- Q: What does OBD-II code P1212 mean?
Code P1212 indicates: Ignition Coil 3 Control Circuit Low. This is a GM manufacturer-specific diagnostic trouble code.
- Q: Is code P1212 serious?
Severity: Major. Immediate attention is recommended to prevent further damage.
- Q: Can I drive with code P1212?
It is not recommended to drive with this code active as it may cause further damage.
- Q: How do I fix code P1212?
Diagnose the Ignition system, check wiring and connectors, test the related sensor or actuator, and replace faulty components as needed.
Source: OBD-II Manufacturer Extended Codes / SAE J2012 / OBD-Codes.com
Category: OBD-II