Charging System Indicator Circuit Troubleshooting
  1. Check for continuity between ECM/PCM connector terminal B46 and alternator 4P connector terminal No. 3.
Is there continuity?
YES -
Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM. ■
NO -
Repair open in the wire between the alternator and the ECM/PCM.■