P0264

P0264 indicates the ECM has detected cylinder 2 injector circuit current below the expected threshold during commanded pulses, pointing to a shorted injector coil, a short to ground in the injector harness, or a failed low-side driver in the ECM. Cheapest diagnostic: ohm the cylinder 2 injector across its two pins with the connector unplugged — saturated drivers should read 11-17 ohms, low-impedance peak-and-hold injectors read 1.5-4 ohms; anything below the low end of the platform's spec indicates winding shorted-turns. Check harness routing along the intake — V-engines run cylinder bank harnesses across the valley and chafe against intake bolts and EGR brackets, particularly on GM trucks and Mopar Hemi platforms. Backprobe the injector control wire and use a noid light or low-current clamp to verify the ECM is still pulsing; if pulses are present and ohms are good, the injector itself is internally shorted under heat. Caveat: a fuel-fouled injector that drags excessive current at startup can intermittently trip P0264 while cold and clear when warm — capture freeze-frame ECT to determine if the fault is thermal.

Vehicle-specific patterns: 2007-2013 Chevy Silverado 5.3L (LMG/LC9) — same harness chafe pattern as cylinder 1, second injector position from front of intake. 2006-2010 Jeep Grand Cherokee 5.7L Hemi — cylinder 2 injector internal short under prolonged heat soak, replace injector 05037479AA. 2005-2009 Ford Mustang 4.6L 3V — injector connector EV1-style pin fretting, replace pigtail before full injector. 2007-2012 Nissan Frontier/Xterra 4.0L (VQ40DE) — injector harness rub-through behind the upper intake plenum, repair harness and reloom. Estimated repair: $80 to $550.