P28F3Engine Disconnect Clutch Pressure Sensor Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P28F3 is stored when the voltage of the disconnect clutch pressure sensor drops below the smallest value a healthy part can output, a level that stands for an electrical fault, not for an open clutch. The usual suspects are a signal wire chafed against ground, a sensor reference supply that is missing or dragged down by another shorted sensor on the same feed, or a failed sensor. No manufacturer documents P28F3 with a threshold in public. Ford uses a separate pressure sensor at this clutch in its 10R80 hybrid gearbox, and a Hyundai patent shows the same single-sensor layout for the engine clutch. CARB requires out-of-range checks on such inputs. P28F4 is the high fault and P28F1 the unspecified circuit fault. The controller usually keeps the clutch open or runs it without feedback.
- What you may notice
- Hybrid or transmission warning light
- Engine coupling blocked, car runs electrically or in limp mode
- Harsh engagement if the clutch is still used
- Likely causes
- LikelySignal wire shorted to ground through chafed insulation
- PossibleSensor reference supply missing or pulled low by another shorted sensor
- PossiblePressure sensor failed with output stuck low
- 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 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.