Code Definition

P0843 — Transmission Fluid Pressure Sensor/Switch A Circuit High

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

About P0843

P0843 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 P0843 is stored, the module has detected a signal or supply voltage higher than the expected operating range; and 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 P0843 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 P0843 fault code is activated when the control module detects a higher than normal voltage or signal in the Transmission Fluid Pressure Sensor/Switch 'A' circuit. This condition often indicates an electrical fault, such as a short to power in the circuit. A high signal from the pressure sensor can lead to incorrect readings of the hydraulic pressure, which may affect the transmission's operational characteristics.

Quick Facts