P0265

P0265 indicates the PCM saw the cylinder 2 injector low-side driver circuit stuck at high voltage during the commanded ON pulse, the same failure family as P0262 but on a different cylinder, root causes are an open injector winding, a broken or corroded signal wire from the PCM to the injector, or a short to battery positive on the driver lead. Cheapest-first diagnostic ladder: pull the cylinder 2 injector connector and ohm the injector windings, port-fuel injectors should fall between 11.4 and 18 ohms at room temp and GDI injectors 1.5 to 4 ohms, an open reading or a value more than 2 ohms off the other cylinders is the smoking gun; next verify the 12V supply side at the connector with key-on (battery voltage minus 0.5V is healthy), then back-probe the driver lead with a scope and watch for the inductive flyback spike around 60-80V on the trailing edge of each pulse, no spike means no current flow. Wiggle-test the harness at the engine-bay-to-firewall transition and along any clip points where the loom passes near hot exhaust components. Expensive misdiagnosis: replacing the injector when the actual fault is a broken pin retainer in the connector body letting the terminal back out under vibration, the injector ohms fine on the bench but the circuit reads open in-vehicle, always inspect the connector terminal tension with a pin-pull test before condemning the injector.

Vehicle-specific patterns: 2004-2008 Ford F-150 5.4L 3V Triton has a known injector connector heat-fatigue issue where the plastic shell cracks and lets the terminals lose contact, replacement pigtails are a standard repair; 2006-2011 Honda Civic R18 sees harness chafe against the valve cover bolt boss on cylinder 2's pigtail; 2008-2013 Cadillac CTS 3.6L direct-injection (LLT/LFX) throws P0265 when a high-pressure injector solenoid winding opens internally, GM bulletin PIP5029 covers the diagnostic flow. Estimated repair: $200 to $900.