P28D7Clutch B Pump Motor Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P28D7 judges motor and pump of clutch B as one unit: the oil pressure seen by the sensor, or the speed and current the motor needs for it, does not match the target. Getrag's hydraulic plan for the 7DCT300 has both clutch pumps drawing through a common suction filter, with a pressure sensor downstream of both pumps providing feedback. If P28D7 and the clutch A code P28C8 are stored together, the shared filter or the oil level is therefore a natural suspect; P28D7 on its own points more towards the clutch B pump, its gerotor set or leaking seals in the clutch B circuit. An EVS32 study with Hyundai found such on-demand pumps cut actuation energy by 96.5 % in the WLTP versus an engine-driven pump. No manufacturer documents P28D7 publicly.
- What you may notice
- Clutch B slips or engages late
- Transmission warning, gears on clutch B possibly locked out
- Unusual humming from the actuator area
- Likely causes
- LikelyClogged common suction filter, especially if P28C8 is stored too
- PossibleLeaking seals in the clutch B pressure circuit
- PossibleWorn or contaminated gerotor set of the clutch B pump
- RareTransmission fluid level too 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: €150 – €1,600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.