Cylinder #6 Ignition Coil Short Circuit
Code P1266 indicates a short circuit between the high and low sides of the ignition coil for cylinder #6. This typically means the coil's primary or secondary windings have failed, causing an electrical short that prevents proper spark generation. The engine control module (ECM) detects abnormal current flow and sets this code. Common causes include a faulty ignition coil, damaged wiring, or a shorted connector.
1. Symptoms You Will Notice
- Engine misfire on cylinder #6
- Check Engine Light illuminated
- Rough idle or hesitation
- Reduced fuel economy
2. Most Common Causes
- Faulty ignition coil on cylinder #6
- Shorted wiring or connector at coil #6
- ECM internal fault (rare)
3. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P1266 is present.
Step 2: Visually inspect ignition coil #6 and its wiring for damage or corrosion.
Step 3: Swap coil #6 with another cylinder and see if the code moves.
Step 4: If code moves, replace the faulty coil. If not, test wiring continuity and ECM output.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with a misfire can damage the catalytic converter and cause poor performance.
How much does it cost to fix?▼
Typically $50-$150 for a new ignition coil and labor, depending on vehicle make and model.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.