Alternator FR Signal Circuit Troubleshooting
- Start the engine, and let it idle.
- Monitor the ALTERNATOR in the DATA LIST with the HDS.
- Check if the indicated percentage changes when the headlight switch is turned on.
Does the percentage vary?
YES - The alternator signal circuit is OK.
NO - Go to step 4.
- Turn the headlight switch and ignition switch OFF.
- Jump the SCS line with the HDS.
- Disconnect the alternator 4P connector.
- Disconnect PCM connector A (31P).
- Check for continuity between body ground and PCM connector terminal A12.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Repair short in the wire between the PCM (A12) and the alternator.
NO - Update the PCM if it does not have the latest software (see UPDATING THE PCM ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ).