Code Definition

P0945 — Hydraulic Pump Relay Circuit Open

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

About P0945

P0945 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 P0945 is stored, the module has detected an open (broken or disconnected) electrical path in the monitored circuit.

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 P0945 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 P0945 fault code is set when the control module detects an open circuit condition in the hydraulic pump relay circuit. This relay plays a crucial role in controlling the power supply to the hydraulic pump, which in turn is responsible for maintaining the hydraulic pressure in systems like the transmission or power steering. An open circuit in the relay circuit means there is a break in the electrical path, preventing current from reaching the hydraulic pump. This can be due to a faulty relay, broken wires, disconnected connectors, or a fault within the control module. The absence of power ...

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