Error Code P0351
Moderate Issue
DTC Code P0351 indicates an Ignition Coil 1 Control Circuit issue, where the ECM detects a mismatch between the commanded and actual state of the ignition coil control circuit.
What symptoms indicate Error Code P0351?
- Engine Light ON: The check engine light or service engine soon warning light illuminates, indicating an issue with the ignition coil 1 control circuit.
- Lack/Loss of Power: The vehicle may experience a noticeable reduction in power, which can be linked to the ignition coil not functioning properly.
- Engine Harder to Start: The engine may require more effort to start, potentially due to a malfunctioning ignition coil affecting the ignition process.
- Engine Hesitation: There may be a delay or hesitation when accelerating, which can be associated with ignition coil issues.
- Rough Engine Idle: The engine may idle roughly, indicating a possible problem with the ignition coil affecting engine performance.
What causes OBD code Error Code P0351?
- The ignition coil may be defective, leading to improper spark generation and engine misfires.
- An open or shorted harness in the ignition coil circuit can disrupt the electrical flow, causing the coil to malfunction.
- Poor electrical connections in the ignition coil circuit can result in intermittent or weak signals, affecting engine performance.
- A malfunctioning Engine Control Module (ECM) can fail to send the correct signals to the ignition coil, leading to ignition issues.
How to fix OBD code Error Code P0351?
- Initial Inspection: Visually inspect the ignition coil, wiring, and connectors for any signs of damage, corrosion, or loose connections. Ensure that the ignition coil is properly seated.
- Check Power Supply: Using a multimeter, verify that there is battery voltage at the ignition coil connector with the ignition key in the ON position. If voltage is absent, trace the wiring back to the power source to identify any breaks or faults.
- Test Ground Circuit: Ensure the ground circuit for the ignition coil is intact. Use a multimeter to check for continuity between the ignition coil ground terminal and the engine block.
- Inspect Control Circuit: Check the control circuit from the Engine Control Module (ECM) to the ignition coil. Use an oscilloscope to verify the presence of a control signal when the engine is cranking or running.
- Swap Ignition Coils: Swap the ignition coil with another cylinder to see if the problem follows the coil. If the DTC changes to the new cylinder, the ignition coil is faulty.
- ECM Testing: If all previous steps are inconclusive, test the ECM for proper operation. Ensure it is sending the correct signals to the ignition coil.