Code Definition

P0115 — Engine Coolant Temperature Circuit Malfunction

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

About P0115

P0115 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 P0115 is stored, the module has detected an electrical-circuit fault in the wiring, connector, or driver associated with the named component.

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 P0115 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 P0115 code indicates a malfunction in the circuit of the Engine Coolant Temperature (ECT) sensor. This sensor measures the temperature of the engine's coolant and is critical for the Engine Control Module (ECM) to monitor and regulate the engine's operating temperature. The ECM sets this code when it detects a problem in the ECT sensor circuit, such as an open or short circuit, which can affect engine performance, fuel efficiency, and emissions control.

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