Code Definition

P0845 — Transmission Fluid Pressure Sensor/Switch B Circuit

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

About P0845

P0845 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 P0845 is stored, the module has detected a sensor-related fault — the reported value from the named sensor is out of spec.

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 P0845 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 P0845 fault code is triggered when the control module identifies an issue with the Transmission Fluid Pressure Sensor/Switch in Circuit 'B.' This sensor/switch is responsible for monitoring the hydraulic pressure in a specific part of the transmission. The code indicates that there is a problem with the electrical circuit of the sensor/switch, which could be due to a malfunction within the sensor/switch itself, issues with the wiring or connectors, or a fault in the control module's circuitry related to this sensor.

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