Malfunction Indicator Lamp (MIL) ON Steady
MIL Circuit Troubleshooting1. Turn the ignition switch ON (II) and watch the Malfunction Indicator Lamp (MIL).
Does the MIL come on and stay on for more than 20 seconds after turning the ignition switch ON (II)?
YES - If the MIL always come on and stays on, go to step 2. But if the MIL sometimes works normally, first check for these problems.
- An intermittent short in the wire between the PCM (A10) and the Data Link Connector (DLC).
- An intermittent open in the wire between the PCM (A21) and the DLC.
- An intermittent short in the wire between the PCM (A18) and the gauge assembly.
2. Turn the ignition switch OFF.
3. Connect an OBD II scan tool/Honda PGM Tester.
4. Turn the ignition switch ON (II).
5. Read the OBD II scan tool/Honda PGM Tester.
Does the OBD II scan tool/Honda PGM Tester communicate with the PCM?
YES - Go to step 28.
NO - Go to step 24.
6. Turn the ignition switch OFF.
7. Disconnect PCM connector A (32P).
8. Check for continuity between body ground and Data Link Connector (DLC) terminal No. 7.
Is there continuity?
YES - Repair short in the wire between the DLC and the PCM (A21). After repairing it, check the DTC with the OBD II scan tool/Honda PGM Tester and go to the DTC Troubleshooting Index.
NO - Go to step 27.
9. Check for continuity between PCM connector terminal A21 and DLC terminal No. 15.
Is there continuity?
YES - Substitute a known-good ECM/PCM and recheck. If the symptom/indication goes away, replace the original ECM/PCM.
NO - Repair open in the wire between the DLC and the PCM (A21). After repairing it, check the DTC with the OBD II scan tool/Honda PGM Tester and go to the DTC Troubleshooting Index.
10. Check the OBD scan tool/Honda PGM Tester for DTCs.
Are any DTCs indicated?
YES - Go to the DTC Troubleshooting Index.
NO - Go to step 29.
11. Turn the ignition switch OFF, then turn it back ON (II).
12. Measure voltage between PCM connector terminal A10 and body ground.
Is there about 5 V (or battery voltage)?
YES - Go to step 31.
NO - Repair short in the wire between the DLC and the PCM (A10).
13. Turn the ignition switch OFF.
14. Disconnect PCM connector A (32P).
15. Turn the ignition switch ON (II).
Is the MIL on?
YES - Repair short in the wire between the gauge assembly and the PCM (A18).
NO - Substitute a known-good PCM and recheck. If the symptom/indication goes away, replace the original PCM.