P21D8Cylinder 10 Injector B Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P21D8 covers the second injector of cylinder 10, the last cylinder of a V10. No manufacturer documents this code publicly. A V10 with two injectors per cylinder is on record in the Lamborghini Huracán, whose engine combines direct and multipoint injection, yet which of them its software would call B is unknown. For comparison, Ford's eight-cylinder logic tests B circuits continuously above 11 V for 5 s, and GM's LT5 module rates an open by 200 kOhm or more with the driver off. CARB obliges makers to monitor injector output circuits whose failure can raise emissions. In practice the fault would show as a misfire on cylinder 10 (P0310) with that cylinder still fed by its other injector; the A-side equivalent would be P020A. Neighbours are P21D7 and P21D9.
- What you may notice
- Check engine light on
- Misfire on cylinder 10 (P0310)
- Likely causes
- LikelySecond injector of cylinder 10 open internally
- PossibleWiring or connector fault at the cylinder 10 injector
- RareOutput stage in the engine control module failed
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €150 – €1,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.