Code Definition

P0425 — Catalyst temperature sensor signal error bank 1 sensor 1

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

About P0425

P0425 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 P0425 is stored, the module has detected 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 P0425 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 powertrain control module (PCM) sets P0425 when it detects an issue with the signal from the catalyst temperature sensor located upstream (Sensor 1) of the catalytic converter on Bank 1. This sensor monitors the exhaust gas temperature to ensure the catalyst operates within the optimal range. A signal error may indicate an electrical issue, sensor failure, or incorrect readings outside expected parameters.

Quick Facts