P2DD6Fuel Injection Quantity B Higher Than Expected
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- With P2DD6 the engine control has found that path B injects more fuel than requested, so the mixture ends up richer than planned. Typical reasons are an injector that drips after closing, a worn nozzle passing extra fuel, or rail pressure above target; a sensor that under-reads airflow can fake the same result. On diesels this shows up as soot: more black smoke and shorter intervals between filter regenerations. No manufacturer publishes P2DD6 itself. Ford's 2023 diesels flag the matching global fault as P0172 once the filtered fueling error exceeds +0.15; GM scales its upper limit for A with ambient pressure. P2DD5 is the shortfall in path B, P2DD8 the same excess during cold start.
- What you may notice
- Check engine light on
- Black smoke, more frequent particulate filter regeneration
- Higher fuel consumption
- Likely causes
- LikelyInjector in group B dripping or nozzle worn
- PossibleRail pressure above target (regulator, pressure sensor)
- PossibleAirflow sensor reading low or intake leak after the sensor
- RareWrong injector part fitted
- 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: €100 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.