Honda Accord: Alternator FR Signal Circuit Troubleshooting

1. Start the engine, and let it idle.

2. Monitor the ALTERNATOR in the DATA LIST with the HDS.

3. Check if the indicated percentage varies when the headlight switch is turned on.

Does the percentage wary? YES

-The alternator signal circuit is OK.gH NO

-Go to step 4.

4. Turn the headlight switch off and ignition switch to LOCK (0).

5. Jump the SCS line with the HDS.

6. Disconnect the alternator 4P connector.

7. Disconnect ECM/PCM connector B (49P).

8. Check for continuity between ECM/PCM connector terminal B47 and body ground.

ECM/PCM CONNECTOR B (49P)

Terminal side of female terminals

Is there continuity? YES-

Repair short in the wire between the ECM/PCM (B47) and the alternator.

NO

-Update the ECM/PCM if it does not have the latest software (see page 11-203), or substitute a known-good ECM/PCM (see page 11-7), then recheck.

If the symptom/indication goes away and the ECM/PCM was updated, troubleshooting is complete.

If the symptom/indication goes away and the ECM/PCM was substituted, replace the original ECM/PCM (see page 11-204).