P0293

P0293 is the cylinder 11 injector circuit LOW fault — same failure mode as P0290 but on cylinder 11, which restricts the diagnosis to V12 engines almost exclusively (cylinder 11 doesn't exist on a V10). The PCM is commanding the cylinder 11 injector to open and seeing current ramp below the expected 0.5-1.5A peak threshold during the injection pulse, which means open winding, high-resistance harness, partial short, or PCM injector-driver failure on that channel. Cheapest-first ladder: (1) Confirm cylinder 11's physical location from the FSM — on a BMW V12 (N73/N74, used in 7-Series and Rolls-Royce Phantom/Ghost/Wraith) cylinder 11 is on the right bank rear; on a Mercedes-Benz M275/M279 V12 biturbo (S600, SL600, CL600, S65 AMG) cylinder 11 is on the left bank near the rear; on a Lamborghini/Audi V12 (Aventador, A8 W12 if treated as V12) cylinder 11 is rear-bank. (2) Pull the cylinder 11 injector connector and ohm out the winding — V12 saturated-driver injectors typically read 12-16 ohms; piezo direct-injection injectors on the Mercedes M279 and BMW N74 are NOT ohm-testable in the conventional sense and require an inductance-capacitance test with OEM-level scan tools. (3) Probe the connector for battery voltage on the power side and use a noid light or scope to verify the PCM driver is pulsing ground on the signal side. (4) Swap the injector with an adjacent same-bank cylinder (and re-code if direct-injection) and clear; if P0293 follows the injector, the injector is bad, if it stays on cylinder 11, the wiring or PCM is the cause. The expensive misdiagnosis: don't replace a BMW N74 or Mercedes M279 piezo injector based on an ohm reading alone — these injectors don't respond to conventional resistance tests and a swap-test with proper coding is the only valid diagnostic; condemning one based on a multimeter reading wastes a $1,200-2,200 part.

Vehicle-specific patterns: 2009-2015 BMW N74 6.0L V12 twin-turbo (760Li, Rolls-Royce Ghost/Wraith/Phantom) sets P0293 from piezo injector failure on the right-bank rear cylinders where the turbo heat soak is worst — these injectors are $1,400-2,200 each, must be coded to the DME, and there's a known BMW production cluster around 2010-2012 VINs that fails early. 2007-2014 Mercedes-Benz M275/M279 V12 biturbo (S600, CL600, SL600, S65 AMG, S600 Maybach) sets P0293 from injector connector failure and from a sub-harness chafe under the engine cover at the rear of the left bank. 2011-2022 Lamborghini Aventador 6.5L V12 sets P0293 from injector failure on the rear cylinders that share an exhaust-manifold heat path with the catalysts. Note that the Hemi 6.4 SRT, Ford 6.8 V10, and Audi R8 V10 do NOT have a cylinder 11 — if P0293 is being reported on those engines it's a scanner database error and the actual code should be re-pulled with a manufacturer-specific tool. Estimated repair: $400 (Mercedes M275 injector + coding at indie shop) to $3,500 (BMW N74 or Lambo V12 injector replacement at dealer with full coding and adaptation reset).