Code Definition

P0A90 (241) — Drive motor A performance

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Toyota

About P0A90

P0A90 is a generic (obd-ii standard) powertrain diagnostic trouble code recorded for Toyota vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0A90 is stored, the module has detected a plausibility fault — the measured value is in the electrical range but is not consistent with expected operating behaviour.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0A90 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

On Toyota and Lexus hybrids the hybrid vehicle control ECU evaluates Motor Generator 2 (MG2), the main traction motor known as Drive Motor A, using torque feedback, speed sensor data, and inverter signals. This manufacturer subcode of P0A90 sets when the ECU sees a persistent and significant deviation between commanded and actual MG2 torque or speed during steady or continuous operation, sustained beyond the calibrated threshold and duration. Unlike the subcodes that trigger on intermittent or load specific events, this one indicates consistent inefficiency or degradation, so a hard fault in t...

Join TaT to view the complete code information and diagnostic details.

Quick Facts