P0351: Ignition Coil A Primary/Secondary Circuit Range/Performance Problem

Definition

The OBD2 code P0351 indicates a problem with the ignition coil A's primary or secondary circuit, suggesting an issue with its range or performance, which can affect engine ignition and operation

Common causes

Faulty ignition coil
Bad spark plug
Damaged wiring or connectors
Faulty ignition control module
Poor ground connection
Engine control module (ECM) issues
High resistance in the ignition coil circuit
Short circuit in the ignition coil circuit

Common misdiagnoses

Faulty ignition coil
Bad spark plugs
Ignition control module issues
Wiring or connector problems
Engine control unit (ECU) malfunction
Fuel system issues
Vacuum leaks
Timing belt or chain problems
Crankshaft or camshaft position sensor failure
Battery or charging system issues

Troubleshooting steps

1. Check for Additional Codes

Before proceeding, check for any other related trouble codes that may provide more context to the problem
2. Visual Inspection
3. Inspect the ignition coil and its wiring for any visible damage, such as frayed wires, corrosion, or loose connections
4. Check the connectors for signs of wear or poor contact
5. Test the Ignition Coil
6. Use a multimeter to measure the resistance of the ignition coil. Compare the readings to the specifications provided in the vehicle's service manual
7. If the resistance is outside the specified range, the ignition coil may be faulty and should be replaced
8. Check the Power and Ground Supply
9. Verify that the ignition coil is receiving the correct voltage. Use a multimeter to check for power at the coil connector while the ignition is on
10. Ensure that the ground connection is solid and free of corrosion
11. Inspect the Ignition Control Module (ICM)
12. If applicable, check the ignition control module for proper operation. A malfunctioning ICM can affect the performance of the ignition coil
13. Test the ICM according to the manufacturer's specifications
14. Examine the PCM (Powertrain Control Module)
15. The PCM controls the ignition coil operation. If other components are functioning correctly, the PCM may be at fault
16. Check for any software updates or recalls related to the PCM
17. Check for Shorts or Open Circuits
18. Inspect the wiring harness for shorts to ground or open circuits that could affect the ignition coil's performance
19. Use a multimeter to test continuity in the wiring
20. Inspect Spark Plugs and Wires
21. Check the condition of the spark plugs and ignition wires. Worn or damaged spark plugs can cause misfires and affect coil performance
22. Replace any faulty spark plugs or wires as necessary
23. Perform a Coil Swap Test
24. If the vehicle has multiple ignition coils, consider swapping the coil with another cylinder to see if the code follows the coil. This can help determine if the coil itself is faulty
25. Clear the Codes and Test Drive
26. After performing the necessary repairs, clear the trouble codes using an OBD-II scanner and take the vehicle for a test drive to see if the code reappears. 1
27. Consult a Professional
28. If the issue persists after following these steps, it may be best to consult a professional mechanic for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P0351 code

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check for Additional Codes

2. Visual Inspection

3. Inspect the ignition coil and its wiring for any visible damage, such as frayed wires, corrosion, or loose connections

4. Check the connectors for signs of wear or poor contact

5. Test the Ignition Coil

6. Use a multimeter to measure the resistance of the ignition coil. Compare the readings to the specifications provided in the vehicle's service manual

7. If the resistance is outside the specified range, the ignition coil may be faulty and should be replaced

8. Check the Power and Ground Supply

9. Verify that the ignition coil is receiving the correct voltage. Use a multimeter to check for power at the coil connector while the ignition is on

10. Ensure that the ground connection is solid and free of corrosion

11. Inspect the Ignition Control Module (ICM)

12. If applicable, check the ignition control module for proper operation. A malfunctioning ICM can affect the performance of the ignition coil

13. Test the ICM according to the manufacturer's specifications

14. Examine the PCM (Powertrain Control Module)

15. The PCM controls the ignition coil operation. If other components are functioning correctly, the PCM may be at fault

16. Check for any software updates or recalls related to the PCM

17. Check for Shorts or Open Circuits

18. Inspect the wiring harness for shorts to ground or open circuits that could affect the ignition coil's performance

19. Use a multimeter to test continuity in the wiring

20. Inspect Spark Plugs and Wires

21. Check the condition of the spark plugs and ignition wires. Worn or damaged spark plugs can cause misfires and affect coil performance

22. Replace any faulty spark plugs or wires as necessary

23. Perform a Coil Swap Test

24. If the vehicle has multiple ignition coils, consider swapping the coil with another cylinder to see if the code follows the coil. This can help determine if the coil itself is faulty

25. Clear the Codes and Test Drive

26. After performing the necessary repairs, clear the trouble codes using an OBD-II scanner and take the vehicle for a test drive to see if the code reappears. 1

27. Consult a Professional

28. If the issue persists after following these steps, it may be best to consult a professional mechanic for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P0351 code