OBD-II code · Powertrain (generic, extended)
P28D9 Clutch B Motor Underspeed
The clutch B actuator motor falls below the calibrated minimum speed for the commanded duty. High mechanical load or supply voltage low.
Is it safe to drive with P28D9?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyMechanical load increased (binding)
- PossibleSupply voltage low under load
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 3–10 h
- Emissions test
- Usually unaffected
- Parts involved
- Clutch Motor B, Clutch Actuator B
Related codes
- P28CAClutch A Motor Underspeed
- P28D6Clutch B Motor Driver Current/Temperature Too High
- P28D7Clutch B Pump Motor Performance
- P28D8Clutch B Motor Overspeed
- P28DAClutch B Motor Position Sensor Circuit/Open
- P28DBClutch B Motor Position Sensor Circuit Range/Performance
- P28DCClutch B Pressure Sensor Circuit/Open
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.