Code Definition

P043C — Catalyst temperature sensor circuit low Bank 2 sensor 2

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

About P043C

P043C 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 P043C is stored, the module has detected a signal or supply voltage lower than the expected operating range; a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine; 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 P043C 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

This fault code is set when the engine control module (ECM) detects a lower than expected voltage from the catalyst temperature sensor on Bank 2 Sensor 2. This condition typically indicates a partial short or excessive resistance in the sensor circuit, causing a decrease in the voltage signal. The ECM sets this code when the voltage falls below a predetermined threshold, which is considered outside the normal operating range.

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