P0117
DTC P0117: ECT Sensor Circuit Low Voltage1. Turn the ignition switch ON (II).
2. Check the ECT with the scan tool.
Is 150 °C (302 °F) or higher (or H-Limit in Honda made of PGM Tester) or 0 V indicated?
YES - Go to step 3.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the ECT sensor and at the ECM.
3. Disconnect the ECT sensor 2P connector.
4. Check the ECT with the scan tool.
Is 150 °C (302 °F) or higher (or H-Limit in Honda mode of PGM Tester) or 0 V indicated?
YES - Go to step 5.
NO - Replace the ECT sensor.
5. Turn the ignition switch OFF.
6. Disconnect ECM connector B (24P).
7. Check for continuity between the ECT sensor 2P connector terminal No.1 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (B8) and the ECT sensor.
NO - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.