Code Definition

P0A90 (240) — 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 compares Motor Generator 2 (MG2) actual output against a modelled reference. This manufacturer subcode of P0A90 sets when a torque or rotational speed deviation for MG2 is detected under acceleration or regenerative braking, a different operating window from the related subcode that monitors steady driving. The ECU flags the fault when actual MG2 torque or speed differs from the expected model beyond the calibrated threshold, which often points to intermittent or load dependent degradation in the motor, its resolver, or the inverter th...

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

Quick Facts