Code Definition

P0A79 — Drive motor B inverter performance

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

About P0A79

P0A79 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0A79 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 P0A79 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

The inverter for Drive Motor B converts high voltage DC from the battery into the three phase AC that drives the motor, under the control of the power electronics or motor control module. DTC P0A79 sets when the module detects improper operation or degraded performance of that inverter, with output not meeting the expected values for commanded torque, voltage, and current feedback, or the inverter control logic misbehaving. Common causes include degraded or overheated power transistors, a cooling system fault, a weak high voltage supply, a gate driver or current sensing fault, or a software is...

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