Alternator FR Signal Circuit Troubleshooting

Information marked with an asterisk (*1) applies to '09-11 models.
Information marked with an asterisk (*2) applies to '12 model.

Start the engine, and let it idle.
Monitor the ALTERNATOR in the DATA LIST with the HDS.
Check if the indicated percentage varies 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 OFF.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect the alternator 4P connector.
Disconnect PCM connector C (49P).
Check for continuity between PCM connector terminal C44 and body ground.

Fig 1: Checking Continuity Between PCM Connector Terminal C44 And Body Ground

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair short in the wire between the PCM (C44) and the alternator. ■

NO -Update the PCM if it does not have the latest software (see PCM UPDATE ), 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 ). ■