Code Definition

P2003 (01) — Controller Power Supply Voltage High

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

About P2003

P2003 is a generic (obd-ii standard) powertrain diagnostic trouble code recorded for Mercedes-Benz vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P2003 is stored, the module has detected a signal or supply voltage higher than the expected operating range.

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 P2003 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

This fault code indicates that the powertrain control module (PCM) or another control unit has detected an excessively high voltage in its power supply circuit. The module monitors the supply voltage to ensure stable operation, and if the voltage exceeds the predefined upper limit, it triggers this fault. Prolonged overvoltage conditions can lead to electronic component damage or erratic system behaviour.

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