Powertrain, generic (extended)

P28E4 Shift Motor Driver Current/Temperature Too High

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

P28E4 says the output stage that powers the shift motor has reached its current or temperature limit and has protected itself. A blocked actuator is the classic trigger: if the detent plate, the park pawl linkage or the gear train inside the actuator binds, the motor stalls and current climbs. Shorts between phases, or many range changes in a row in hot conditions, can also heat the driver. No manufacturer documents P28E4 publicly. In a Denso shift range patent the motor driver energises the three phases and a motor relay sits between driver and battery, so the controller can cut power when a limit is hit; Hyundai Kefico integrates control unit and brushless motor in one SBW actuator. CARB requires circuit and functional checks on outputs. Until it cools down, the system may refuse shifts.

Likely causes

Detent mechanism, park pawl linkage or actuator gearing binding
Short between two motor phases
Driver overheated after repeated range changes or high ambient heat

Symptoms

  • Shift system warning in the cluster
  • Range change stops halfway or is refused
  • Problem may disappear after the system cools down

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,600
Time1–4 h

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

Parts involved

shift motorshift motor position sensortcm

Related codes

P28E0P28E1P28E3P28E5

References: law.cornell.edu, patents.google.com, hyundai-kefico.com.