P21D4Cylinder 6 Injector B Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P21D4 is the last B injector code on a six-cylinder engine. Ford's second-generation 2.7 and 3.5 EcoBoost V6 combine port and direct injection, label the port injectors B and test this circuit together with P21CF to P21D3, continuously above 11 V within 5 s; on these engines cylinder 6 is the rear cylinder of the second bank. On the 3.5 the direct system is shut down at low speed and light load and the engine runs on port fuel alone, so an open cylinder 6 port injector is most noticeable at idle and in gentle driving. GM's 2019 LT5 V8 also covers cylinder 6 in its injection module, Type A after 20 of 25 failed samples. The A-side direct injector code is P0206, the misfire code P0306; P21E6 and P21E7 are the low and high faults.
- What you may notice
- Check engine light on
- Misfire on cylinder 6 (P0306)
- Slightly rough idle
- Likely causes
- LikelyPort injector of cylinder 6 open internally
- PossibleDamaged wire at the rear of the engine, hard to inspect
- PossibleConnector not fully latched after earlier work on the intake
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.