P0202

P0202 flags the cylinder 2 injector circuit specifically, indicating the PCM driver for that one injector sees an electrical fault while the rest of the bank reports clean. The diagnostic logic is identical to P0201: confirm the fault is on the injector side and not the harness side before spending money. Cheapest-first ladder: pull the cylinder 2 injector connector and measure resistance at the injector terminals (11 to 17 ohms for port-fuel, 1 to 3 ohms for GDI direct injection, and the value should track within 0.5 ohm of its neighbors at the same temperature); back-probe the connector with the engine running and scope the ground-side pulse, looking for a clean square wave with a pulse-width of 2.5 to 3.2 ms at warm idle ballooning to 18 to 22 ms at WOT, with the driver pulling the line within 0.5V of ground during the on-time. If the scope shows no pulse but the injector tests good, the PCM driver is suspect. Swap injectors 2 and 5 (or any other cylinder) and watch which cylinder the code follows. The expensive misdiagnosis is replacing an entire injector set on a GDI engine for $1,400 when only one injector has dropped resistance or one connector terminal is corroded.

Vehicle-specific patterns: 2005-2010 Chrysler/Dodge 5.7L Hemi Ram and Charger throws P0202 from injector connector corrosion where the harness drapes near the valve cover, often after a valve-cover gasket leak wicks oil into the connector; 2007-2013 GM 5.3L LS Silverado and Tahoe trips P0202 when a Multec injector's coil opens (a known durability issue, GM TSB PIP4568 documents the failure pattern and recommends full bank replacement if two have failed); 2008-2013 BMW N54 throws P0202 alongside P0087 (fuel rail pressure) when the HPFP is dying and the DME mis-attributes pressure-driven misfire to cylinder 2; 2010-2014 Ford 2.0L EcoBoost Edge and Fusion fouls the cylinder 2 GDI injector tip with carbon because of the cross-flow geometry. Estimated repair: $90 to $1,400.