Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
MIL Circuit Troubleshooting
- Turn the ignition switch to ON (II).
- Do the gauge self-diagnostic function (see GAUGE CONTROL MODULE (TACH) INPUT TEST
).
Does the MIL flash?
YES -Go to step 3.
NO -Substitute a known-good gauge control module (tach), and recheck. If the MIL circuit is OK, replace the original gauge control module (tach) (see TACHOMETER ).
- Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION ).
- Check the SCS in the DATA LIST with the HDS.
Is a short indicated?
YES -Go to step 5.
NO -Update the ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
- Turn the ignition switch to LOCK (0).
- Disconnect ECM/PCM connector A (44P), then disconnect the HDS.
- Check for continuity between ECM/PCM connector terminal A31 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair short in the wire between the ECM/PCM (A31) and the SRS unit, the DLC.
NO -Update the ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
NO RELATED
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.