P0206: How to Diagnose & Fix — Injector Circuit/Open - Cylinder 6

The 2017-2023 Ford Transit with the 2.0L EcoBlue diesel engine (available in some markets) and the 3.5L EcoBoost V6 experience fuel injector failures causing rough running, misfires, poor idle, reduced performance, and excessive smoke on cold start. Ford issued a service action for 2.0L EcoBlue vehicles built between February and September 2019 after a batch of high-pressure fuel injectors (reported as Continental-supplied) failed to meet quality standards, causing misfire and reduced engine performance. FordTransitUSAForum.com documents injector failure on 3.5L EcoBoost Transit models as well, where direct injection fuel deposits cause injector spray pattern degradation. RepairPal estimates individual injector replacement between $266 and $627 depending on Transit model, but multiple injectors often need replacement simultaneously, and contaminated fuel systems can cost significantly more.

The 3.5L EcoBoost's high-pressure direct (GDI) injectors run at diesel-like pressures and are a common failure item, especially at higher mileage and after heat-soak. A stuck-open or electrically failing injector floods a cylinder and can wash down neighboring cylinders on the same bank, producing a cold-start misfire that often smooths out once warm. It commonly sets injector-circuit codes (P0201-P0206) alongside misfire codes (P0300-P0306) and occasionally a total-misfire/knock code. It is frequently misdiagnosed as coils or plugs before the injector is found.

The FSI direct-injection injectors shared across the VAG family (Audi/VW/Porsche) are a documented R8 failure point. Injectors can stick open or closed; a stuck-open injector dumps raw fuel into the cylinder and can wash down the bore, while a stuck-closed injector starves the cylinder. One well-known r8talk case had 6 of 8 injectors fail on a 2008 V8 at only 14,000 miles. Symptoms overlap with coil failure (misfires), so proper diagnosis is important, and carbon buildup on the injector tips is a contributing factor.

The 7.3L diesel engines (IDI pre-1994, Powerstroke 1994+) experience injector failure causing rough running, hard starts, and excessive smoke. The IDI injectors are simpler mechanical units; Powerstroke uses HEUI hydraulic electronic injectors.

The 2001-2004 6.6L Duramax RPO LB7 uses injectors buried under the valve covers that are notorious for failing well before 150,000 miles. GM's own analysis attributed the failures to fuel injector body cracks, ball seat erosion, and high-pressure seal extrusion. A leaking injector dumps unburned diesel into the cylinder and past the rings into the crankcase, raising the oil level and diluting it. Owner reporting on duramaxforum.com and silveradosierra.com consistently puts first failures in the 100k-150k range, and because the injectors sit under the valve covers the labor to reach them is far higher than on the later LLY/LBZ engines, where injectors are accessible from the top. This is an LB7-only failure mode - the LLY and later injectors were redesigned and do not share it.