Code Definition

P1115 — ECT Sensor Circuit Intermittent Voltage High

System: Powertrain  |  Type: Manufacturer-Specific  |  Make: Isuzu

About P1115

P1115 is a manufacturer-specific powertrain diagnostic trouble code recorded for Isuzu vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1115 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.

P1115 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

This Isuzu code sets when the Engine Control Module (ECM) intermittently detects a high voltage signal from the Engine Coolant Temperature (ECT) sensor circuit. The ECT sensor is a thermistor whose resistance rises as the coolant cools, and since signal voltage rises with resistance, a high reading corresponds to a cold or open condition. The ECM logs P1115 when it sees erratic readings that momentarily spike above the normal upper threshold and return, which usually points to a brief open or high resistance in the sensor, connector, or wiring. The implausibly cold signal can disturb cold star...

Join TaT to view the complete code information and diagnostic details.

Quick Facts