P1367 Ignition Coil C Secondary Circuit Fault
The P1367 code indicates a malfunction in the secondary circuit of ignition coil C. The secondary circuit generates the high voltage (typically 20,000 to 50,000 volts) needed to create a spark at the spark plug. This code is set when the powertrain control module (PCM) detects an anomaly in the feedback signal from coil C's secondary circuit, which can cause intermittent misfires, no spark, or a weak spark that prevents optimal combustion in the corresponding cylinder.
01. Most Common Causes
- Faulty or internally deteriorated ignition coil C
- Damaged, worn, or high-resistance spark plug wire
- Excessively worn spark plug, damaged electrodes, or incorrect heat range
- Corroded, loose, or high-resistance electrical connections in the secondary circuit
- Degraded insulation or short circuit in the secondary circuit wiring
- Intermittent failure in the ignition module (if applicable)
- Engine mechanical issues causing high combustion chamber resistance (e.g., valve or compression problems)
02. Symptoms You Will Notice
- Engine misfire, especially under load or acceleration
- Rough idle, hesitation, or loss of power
- Check Engine Light illuminated
- Possible hard starting or poor fuel economy
03. Step-by-Step Diagnosis
Scan for codes and verify P1367 is present; check for related misfire codes.
Inspect ignition coil C, spark plug wire, and spark plug for visible damage, wear, or corrosion.
Test ignition coil C primary and secondary resistance with a multimeter; compare to specifications.
Check spark plug wire resistance and spark plug condition; replace if out of spec.
Inspect wiring and connectors for damage, corrosion, or loose connections; repair as needed.
If all else is good, suspect an intermittent ignition module or PCM issue; perform further diagnostics.
1. Frequently Asked Questions
Is it safe to drive?▼
You can drive short distances, but prolonged driving may cause catalytic converter damage due to unburned fuel. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
Typically $100 to $300 for a coil replacement, plus $20 to $50 for spark plugs or wires if needed. Labor adds $50 to $150 depending on the shop.