Powertrain, generic · Hybrid propulsion

P0A20 Motor Torque Sensor Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

This code covers the upper electrical limit of a torque sensor fitted to the traction motor shaft, for example the magnetostrictive design inside a hollow output shaft described in a Honda patent. The control unit sets P0A20 when the sensor voltage remains above the valid range for a calibrated time, which points to a short to the supply voltage, an open ground return or a sensor output stuck high. No manufacturer documents P0A20 publicly; CARB requires an approved drive motor monitor. Siblings: P0A19 low, P0A18 implausible torque, P0A21 intermittent, P0A17 general circuit. Expect a hybrid warning and limited electric torque.

Likely causes

Signal line shorted to sensor supply or battery voltage
Open sensor ground return
Sensor electronics output stuck high

Symptoms

  • Hybrid system warning light
  • Electric drive torque limited
  • Reduced acceleration in electric mode

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–3,000
Time1–8 h

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

Parts involved

motor torque sensorwiring harnesshybrid control module

Related codes

P0A17P0A18P0A19P0A21

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