P1265 - High to Low Side Short Cylinder #5
The P1265 code indicates a short circuit between the high and low sides of the ignition coil or injector circuit for cylinder #5. This typically occurs when the insulation between the primary and secondary windings of the coil breaks down, or when the injector wiring is damaged, causing a direct short. The PCM detects an abnormal current flow and sets this code, often leading to misfire and reduced engine performance.
1. Symptoms You Will Notice
- Engine misfire on cylinder #5
- Check Engine Light illuminated
- Rough idle and reduced power
2. Most Common Causes
- Faulty ignition coil on cylinder #5
- Shorted injector wiring or connector
- Damaged PCM (rare)
3. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P1265 is present.
Step 2: Swap ignition coil #5 with another cylinder and see if the code moves.
Step 3: If code moves, replace the faulty coil. If not, inspect wiring and connector for shorts.
Step 4: Check injector resistance and wiring for shorts; repair as needed.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended as the short can cause further damage to the PCM or other components, and the misfire may lead to catalytic converter damage.
How much does it cost to fix?▼
Typically $50-$150 for a DIY coil replacement; labor and diagnosis at a shop can add $100-$200.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.