Code Definition

P0117 — Engine Coolant Temperature Circuit Low Input

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

About P0117

P0117 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 P0117 is stored, the module has detected a signal or supply voltage lower than the expected operating range.

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 P0117 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 P0117 code indicates a low input condition in the circuit of the Engine Coolant Temperature (ECT) sensor. This sensor measures the temperature of the engine's coolant and is crucial for the Engine Control Module (ECM) to properly manage engine operations, including fuel injection and ignition timing. A low input signal from the ECT sensor might suggest an issue with the sensor or a fault in its circuit, which can lead to problems such as inefficient engine performance, overheating, and increased emissions.

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