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 ECM/PCM connector A (31P).
- Check for continuity between body ground and ECM/PCM connector terminal A12.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair short in the wire between the ECM/PCM (A12) and the alternator.
NO -Update the ECM/PCM if it does not have the latest software (see UPDATING THE ECM/PCM ), 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 ).