Powertrain, generic · Hybrid propulsion

P0A56 Drive Motor B Current Sensor Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0A56 means the current sensor of drive motor B delivers electrically valid values that do not match the operating state, for example a zero-current offset outside its band or a reading that disagrees with a redundant sensor. No manufacturer documents P0A56 publicly. A Hyundai patent covering both the traction motor and the starter-generator flags an abnormal offset compensation by comparing an estimated power-module temperature with the measured inverter temperature; a Caterpillar patent checks that the phase currents of a motor add up to roughly zero. CARB requires rationality checks of hybrid input components. P0A55 is the general circuit fault, P0A57/P0A58 the hard low and high signal, P0A52 the motor A counterpart. Motor B is limited or switched off.

Likely causes

Current sensor offset drifted or offset learning disturbed
Current sensor of drive motor B degraded
Electrical interference on the sensor signal

Symptoms

  • Hybrid warning and MIL
  • Reduced or missing drive from motor B

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€200–4,500
Time1–6 h

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

Parts involved

drive motor b current sensorwiring harnesshybrid control module

Related codes

P0A55P0A57P0A58P0A52P0A5A

References: patents.google.com, patents.google.com, law.cornell.edu.