2014 Chevy Impala 3.6 V6 DTC P0621 Service Charging System Warning Light

In this video we are investigating a 2014 Chevy Impala 3.6 v6 with the battery warning light on and DTC p0621. We find some surprises along the way. The diagnoses and alternator replacement are pretty straight forward.
#chevrolet #chevyimpala #battery #alternator #autotechnician #mechanic #vehicleguru #3.6v6 #car #diy #xtool #diagnosis

[@olenaerhardt7725]

Yesterday I tried to clean EGR ports and passages on our 2001 Saturn SL2 ("service engine" light and code P0401), bcs the code I had was related to ERR Valve. I cleaned the best I could w/Carb Cleaner and rags both EGR Valve w/ports and Throttle Body, since anyway I removed the Air Duct tube. I've read somewhere that to clean the EGR passages you can run the car w/EGR removed for 20 sec. and it will blow out a lot of carbon from the ports. So there was no Air Duct and EGR valve was removed. I switched on the car, it was very ruff idle w/4000 rpm, and sound of engine was very loud. Bcs of all that I counted to 10 and shut off. There was a smell of smth burned, I thought it was burned carbon in ports. Put everything together. When I started the car, the battery sign came to my surprise, since I put a new battery like 2 months ago. I did some research and today measured voltage on the battery when running the car. It showed ~ 11.90V (battery when not running 12.45V), so the alternator didn't work. The scanner showed code P0621, and in that scanner you can read what people reported on that code removal. It was Ignition Coils and Engine Coolant Temperature Sensor. I felt that there is smth not quite right w/this statistics, bcs the alternator is not charging the battery. I'm so glad I came across this informative film. You had the same code P0621 and the Battery Light, and the reason was a faulty alternator. I'll try to replace it tomorrow and see what happens. Thank you very much for your film.

[@andersonsgarage2334]

Running it with the egr removed the hot exhaust gases could have burned some wires. I think thats more likely based on your description.

[@olenaerhardt7725]

@@andersonsgarage2334 I found in Shop Manual (its 3 huge books) I have for that car that there is Inline Fusible Link between the Starter and Alternator in that Saturn. I hope maybe just that link was burned, so can repair or install a new one. The Alternator on Saturn is for 90A, I need to figure out what fuse to put there. I've read usually it is +10% from the specified current. In Performance Test report I found for that alternator the current gets values up to 136A (@6000-7000rpm). To be on the safe side, probably I'll go w/80A fuse. The graph for the test shows ~79-100A @4000-5000rpm, but no way to know what inline fuse was there originally. Thank you kindly for the replay and advice. I'll look for other possible damages to wires.

[@michaelortiz2557]

I have this same code on my 2017 gmc sierra 1500. I’ve replaced the alternator 3 times and the battery once. I have no idea what going on with it. Please help!!

[@andersonsgarage2334]

It may be difficult to do from here, but I can try. Did you have any of the alternators tested?

[@michaelortiz2557]

yes the two tested bad, I did notice the wire from alternator to battery on the battery terminal was burnt up. this alternator isnt the issue i believe.@@andersonsgarage2334

[@guyandottewhiskers2331]

Mine showing 12 volts from alternator and charging battery fine it has to be idiot light never dies or nothing

[@andersonsgarage2334]

If you have access to a scan tool with live data that would help the diagnosis.