P0118
DTC P0118: ECT Sensor Circuit High Voltage1. Turn the ignition switch ON (II).
2. Check the ECT with the scan tool.
Is -4 °F (-20 °C) or less (or L-Limit in Honda mode of PGM Tester) or 5 V indicated?
YES - Go to step 3.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the ECT sensor and the ECM.
3. Disconnect the ECT sensor 2P connector.
4. Connect the ECT sensor 2P connector terminals No.1 and No.2 with a jumper wire.
5. Check the ECT with the scan tool.
Is -4 °F (-20 °C) or less (or L-Limit in Honda mode of PGM Tester) or 5 V indicated?
YES - Go to step 6.
NO - Replace the ECT sensor.
6. Turn the ignition switch OFF.
7. Connect ECM connector terminals C18 and C26 with a jumper wire.
8. Turn the ignition switch ON (II).
9. Check the ECT with the scan tool.
Is -4 °F (-20 °C) or less (or L-Limit in Honda mode of PGM Tester) or 5 V indicated?
YES - 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.
NO - Repair open in the wire between the ECM (C18, C26) and the ECT sensor.