Code Definition

P0637 — Power steering control circuit high

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

About P0637

P0637 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 P0637 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 P0637 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 P0637 fault code is set when the vehicle's control system detects a high voltage condition in the power steering control circuit. This typically indicates an electrical fault within the power steering system, particularly in vehicles equipped with electric power steering (EPS). A high voltage condition can signify an overvoltage situation in the circuit, potentially leading to excessive power steering assistance or damage to the EPS system components.

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