Code Definition

P0A21 — Motor torque sensor signal intermittent

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

About P0A21

P0A21 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 P0A21 is stored, the module has detected a sensor-related fault — the reported value from the named sensor is out of spec.

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 P0A21 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 hybrid or EV powertrain control module continuously monitors the motor torque sensor, which supplies real time feedback on the torque being produced at the electric drive motor. DTC P0A21 sets when the module detects the motor torque sensor signal is intermittent or erratic, fluctuating, dropping out, or becoming noisy outside the normal operating range rather than holding a stable plausible value. Because the fault is intermittent it is typically caused by a marginal connection or harness problem that only disrupts the signal under vibration, temperature change, or specific load. When the...

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