Code Definition

P0870 — Transmission Fluid Pressure Sensor/Switch C Circuit

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

About P0870

P0870 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 P0870 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 P0870 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 fault code P0870 is logged when the control module identifies an issue within the circuitry of the Transmission Fluid Pressure Sensor/Switch 'C'. This problem is detected when the module's expected values from the sensor or switch are not in alignment with the actual signals received. The control module relies on these sensors to monitor the transmission fluid's pressure and adjust operations accordingly. A discrepancy in the sensor/switch 'C' circuit can lead to inaccurate transmission fluid pressure readings, affecting the vehicle's transmission performance.

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