P0282

P0282 sets when the PCM detects the cylinder 8 injector circuit pulled low or shorted to ground; the driver sees a current path it should not when not commanding the injector on. Cheapest first: swap injector 8 with a known-good neighbor and recheck. PFI windings ohm at 11 to 17, GDI at 1.5 to 4; shorted windings drop below 9 ohms PFI or below 1 ohm GDI. With injector unplugged and key on, the driver-side terminal should read open to ground; 0 ohms to chassis ground indicates a harness short, very common where the loom passes the rear exhaust manifold heat shield. Pulse width at warm idle should be 2.5 to 4.5 ms PFI / 0.3 to 0.6 ms GDI; if pulse width on cyl 8 collapses to near 0 ms while the PCM still commands it, the driver has gone into protection. Caveat: GDI systems with a separate injector driver module (Ford EcoBoost, BMW N20/N55, GM Gen V GDI) will throw cylinder-specific lows on a failing IDM with no harness or injector fault present.

Vehicle-specific patterns: 2007 to 2013 GM 5.3L LMG/LC9 trucks have a known harness melt issue on the driver-side bank near the exhaust manifold heat shield bolt; 2008 to 2010 Ford 6.4L Powerstroke diesel sets cylinder-specific lows from cracked injector pigtail solder joints under the valve cover, Ford TSB 09-12-7; 2005 to 2010 Mercedes M273 5.5L V8 with Bosch HDEV-1 GDI injectors fails windings around 80k to 120k miles. Estimated repair: $50 to $760.