LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Honda >> 2000 >> S2000 >> Repair and Diagnosis >> External Pages >> Different car >> Section 11 (PGM-FI System) >> DTC Troubleshooting >> DTC P0116: ECT Sensor 1 Circuit Range/ Performance Problem
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0116: ECT Sensor 1 Circuit Range/ Performance Problem

WARNING: This page is about a different car, the 2009 Honda S2000, 2008 Honda S2000, 2007 Honda S2000, and 2006 Honda S2000. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
  1. Turn the ignition switch to ON (II).
  2. Check ECT SENSOR 1 in the DATA LIST with the HDS.

    Is about 176°F (80°C) or higher, or 0.78 V or less indicated? 

    YES  -Go to step  6.

    NO  -Go to step 3.

  3. Note the value of ECT SENSOR 1 in the DATA LIST with the HDS.
  4. Start the engine. Hold the engine speed at 3,000 RPM without load (in neutral) until the radiator fan comes on, then let it idle.
  5. Check ECT SENSOR 1 in the DATA LIST with the HDS.

    Does ECT SENSOR 1 change 18°F (10°C) or more? 

    YES  -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the ECM.

    NO  -Go to step  11.

  6. Note the value of ECT SENSOR 1 in the DATA LIST with the HDS.
  7. Turn the ignition switch to LOCK (0).
  8. Open the engine hood, and let the engine cool for 3 hours.
  9. Turn the ignition switch to ON (II).
  10. Check ECT SENSOR 1 in the DATA LIST with the HDS.

    Does ECT SENSOR 1 change 18°F (10°C) or more from the value you noted in step 6? 

    YES  -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the ECM.

    NO  -Go to step 11.

  11. Turn the ignition switch to LOCK (0).
  12. Replace ECT sensor 1 (see ECT SENSOR 1 REPLACEMENT ).
  13. Turn the ignition switch to ON (II).
  14. Reset the ECM with the HDS.
  15. Do the ECM idle learn procedure (see ECM IDLE LEARN PROCEDURE ).
  16. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC P0116 indicated? 

    YES  -Check for poor connections or loose terminals at ECT sensor 1 and the ECM, then go to step  1.

    NO  -Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.