P0621 – Alternator warning lamp -circuit malfunction

By BAT Team (Contact Me)
Last Updated 2015-11-18
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Trouble Code	Fault Location	Probable Cause
P0621	Alternator warning lamp -circuit malfunction	Wiring, alternator warning lamp, ECM

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BAT Team Discussions for P0621

2001 impala battery dies every few days
Some thoughts came to me ... and worth adding... if you move the key to off position and remove BEFORE you place shifter in P the system goes AFU. Can remove key and walk away there is still power where it should not be... Can you did you check for B series codes? would you need a diagram- ...