Code Definition

P0626 — Alternator field coil circuit high

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

About P0626

P0626 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 P0626 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 P0626 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 P0626 fault code indicates that the Engine Control Module (ECM) or Powertrain Control Module (PCM) has detected a high voltage condition in the alternator field coil circuit. This circuit controls the magnetic field strength within the alternator, which in turn affects the alternator's charging output. A high voltage reading in this circuit may signify an overcharging situation or a fault in the circuitry that controls the alternator's field coil, potentially leading to damage to the vehicle's electrical components and battery.

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