P0286
Cylinder 9 Injector A Circuit High
Cylinder 9 injector A control voltage above expected range. A flow-deviating injector throws off cylinder balance — adjacent cylinders run leaner/richer to compensate, often masking the root cause until the trim limit is hit.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Wiring shorted to batteryCommon
- Connector pins corroded - high contact resistanceLess likely
- Supply wire pinched against B+ sourceLess likely
Parts involved
- Injector Cyl9
- Injector Wiring
P0286 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.