Code Definition

P0948 — Hydraulic Pump Relay Circuit High

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

About P0948

P0948 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 P0948 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 P0948 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 P0948 fault code is activated when the control module detects a high voltage condition in the hydraulic pump relay circuit. This relay circuit is crucial for controlling the power supply to the hydraulic pump, which in turn is responsible for maintaining hydraulic pressure in systems like the transmission or power steering. A high voltage condition typically indicates an electrical fault, such as a short to power or an internal defect within the relay, leading to voltage levels that exceed the normal operating range. This abnormal voltage can affect the relay's ability to correctly control...

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