Powertrain, generic · Hybrid propulsion

P0A42 Drive Motor A Position Sensor Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0A42 is the counterpart to P0A41: a resolver line of motor A reads above its allowed range. Typical triggers are a sine, cosine or excitation wire shorted to a supply voltage, or an open coil whose line is pulled up by the bias resistors of the input circuit, which drives the converter into clipping. Kia covers it in the same Optima Hybrid 2011-13 bulletin as P0A41: intermittent MIL or hybrid service lamp, fixed by inspecting the HPCU-to-motor sub-harness for internal shorts and pin fit. Bosch patents explain why clipping alone is not enough and how the line offset reveals a short to supply or an open line. P0A3F is the general circuit fault. Expect a warning lamp and reduced or no electric drive.

Likely causes

Resolver wire shorted to a supply voltage inside the sub-harness (Kia Optima Hybrid)
Open sine or cosine line pulled high by the input circuit
Poor pin fit or corrosion at the resolver connectors
Faulty resolver input stage in the motor control unit

Symptoms

  • Intermittent MIL or hybrid service lamp
  • Electric drive disabled or vehicle not ready
  • Reduced power until the fault clears

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–3,500
Time1–8 h

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

Parts involved

drive motor a position sensorwiring harnesshybrid control module

Related codes

P0A41P0A3FP0A40P0A43P0A48P0C53

References: static.nhtsa.gov, patents.google.com, patents.google.com.