What causes P1115 on a Honda?

Engine coolant temperature (ECT) sensor reading intermittent Faulty engine coolant thermostat stuck open Low engine coolant level High resistance in the ECT sensor circuit Corroded ECT sensor connector pins

How do I fix P1115 on a Honda?

Confirm the code and check for related faults Compare the ECT reading to actual engine temperature Check coolant level and thermostat operation Inspect the ECT connector and wiring for high resistance Replace the sensor or thermostat after testing Clear the code and retest

P1115 The engine control module saw the engine coolant temperature sensor signal intermittently high

Q: What does P1115 mean on a Honda?

P1115. The engine control module saw the engine coolant temperature sensor signal intermittently high. The module may read the engine as cold and add extra fuel when the engine is warm.. Applies to Honda and Acura models that use this code.

Category: Powertrain - Fuel/Air Metering
Severity: Check Engine Light
Applies to: Honda and Acura models that use this code

What does P1115 mean on a Honda?

P1115. The engine control module saw the engine coolant temperature sensor signal intermittently high. The module may read the engine as cold and add extra fuel when the engine is warm.. This Honda-enhanced code applies to Honda and Acura models that use this code.

Common causes of P1115

Engine coolant temperature (ECT) sensor reading intermittent
Faulty engine coolant thermostat stuck open
Low engine coolant level
High resistance in the ECT sensor circuit
Corroded ECT sensor connector pins

How to fix P1115

Confirm the code and check for related faults
Compare the ECT reading to actual engine temperature
Check coolant level and thermostat operation
Inspect the ECT connector and wiring for high resistance
Replace the sensor or thermostat after testing
Clear the code and retest

Sources and review

Checked against two independent sources.
Last updated 2026-10-10.