Powertrain, generic (extended)

P28C6 Clutch A Motor Phase U-V-W Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P28C6 is the general circuit code for the three-phase supply of the clutch A motor and is set above all when a phase carries no current although the controller drives it, i.e. an open line. A brushless motor needs all three windings to produce torque; with one missing it stalls or runs roughly, and the gerotor pump behind it can no longer build the oil pressure that engages clutch A. Getrag fitted such ferrite motors as common parts for clutch actuation and shift drums in its pump-actuated DCT family. Typical faults are a backed-out terminal, a cracked solder joint in the actuator, or a broken wire near a moving bracket. P28C4/P28C5 instead describe a voltage pulled low or high. No manufacturer documents P28C6 publicly with values.

Likely causes

Terminal pushed back or loose in the clutch A motor connector
Cracked solder joint or winding connection inside the actuator
Phase wire broken at a bend or bracket

Symptoms

  • Clutch A does not engage, affected gears unavailable
  • Transmission warning and possibly MIL
  • Fault may come and go with vibration or temperature

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,200
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

clutch motor awiring harnesstcm

Related codes

P28C4P28C5P28C7P28D4

References: law.cornell.edu, cti-symposium.world, static.nhtsa.gov.