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  • March 7th, 2019, 07:42 AM
    wungun

    Re: Charging system fault

    Looks like a real PITA to change an alternator put too...

    Sent from my SM-G965W using Tapatalk
  • March 6th, 2019, 06:53 PM
    wungun

    Re: Charging system fault

    I'm beginning to think the same, Ray...

    I've found a used, low mileage OEM one with 6 month warranty for $100.
    I think it'll be worthwhile doing the swap.

    Wish I had the time to pull it and just test the diodes... Probably a $5 fix!
  • March 6th, 2019, 06:26 PM
    RABarrett

    Re: Charging system fault

    I hate to recommend expensive parts without personally checking them, but I suspect the alternator. Possibly a leaking diode causing excessive ripple voltage, the system might condemn the system for that defect. there may be some electronics in the alternator besides the regulator causing the problem. Again, without checking things myself, I hate recommending the replacement of expensive parts. The alternator may be the culprit here. Ray
  • March 6th, 2019, 11:04 AM
    wungun

    Re: Charging system fault

    Well... Got my oil changed. He didn't do anything with looking at the alternator because he would of had to start taking stuff apart just to get at it....
    Ugh!

    Sent from my SM-G965W using Tapatalk
  • March 6th, 2019, 06:05 AM
    wungun

    Re: Charging system fault

    Thanks for the reply!!
    It's in the garage now... They're gonna check the alternator....

    Fingers crossed

    Sent from my SM-G965W using Tapatalk
  • March 5th, 2019, 05:32 PM
    ghur

    Re: Charging system fault

    I am sorry for coming to this thread so late - dont follow the Evoque forums much. I had the same faults on my 2012 car a couple of years ago (battery light on, charging fault, LIN bus fault or something like that plus fairly good charging voltage) and did a lot of head scratching and testing. I finally spoke to an auto electrical guru who immediately said he has encountered the same snag a few times and the alternator is the problem.

    So I removed it and he did an "overhaul" which I think consisted of a new rectifier and bearings. Car has been perfect since.
  • March 3rd, 2019, 10:36 AM
    wungun

    Re: Charging system fault

    As per schematic that I posted, the LIN line goes directly to the passenger footwell, plugged into the body control module.
    I'll suggest the mechanics to clean and reattach alternator ground and power wires.
    I've previously did a hard reset... First with a large power resistor between + and - (while disconnected), then directly + and - together for 30 seconds.
    No effect... Battery light has never gone off since this issue started.

    Sent from my SM-G965W using Tapatalk
  • March 3rd, 2019, 10:21 AM
    RABarrett

    Re: Charging system fault

    Checking the connections at the alternator is wise. Rather than a simple "wiggle" test, I suggest that they loosen, and re-tighten the connections, and have them look for corrosion as well. I think the LIN line goes to the alternator, likely through the multi-wire connector. I suggest that they remove and replace this connector several times, in the event of corrosion. Just have them pull it off and reconnect it several times. One other thing I can suggest is to disconnect one of the battery cables and touch it to the other one, holding it for about 30 seconds. This is a hard reset, but it will likely clear any memory issues. You will likely have to reset the stereo presets, and the clock. Since it will also clear the "scratch pad" in the ECM, there may be a few drivability issues until the "scratch pad" updates. Let us know how it goes. Ray
  • March 2nd, 2019, 10:00 AM
    RABarrett

    Re: Charging system fault

    Typically, these chargers use voltage to determine when the charging should stop. Depending on the charging voltage, when the voltage gets to a predetermined level, and the current drops below a certain value, the charging will stop. As the battery charges, its internal resistance rises, resisting the charge. That internal resistance will make the voltage rise, and the charging current diminish, until cutoff. It is actually the rising internal resistance that causes the current to drop off, and the current draw dropping that causes the voltage to rise. Ray
  • March 2nd, 2019, 08:54 AM
    wungun

    Re: Charging system fault

    I think at this point, everything is pointing to the connections at the alternator or the alternator itself. That or the LIN line to the central junction box.

    She'll be going into the garage for an oil change this week... While they have it in the air, I'll have them check the wiring to the alt.
    (And the awful clunking from the front left suspension!)
  • March 2nd, 2019, 05:44 AM
    wungun

    Re: Charging system fault

    Battery in and connected read 12.61V
    Fired it up... Battery light was still on, than a moment later, "Charging system fault"
    Running, I saw 13.8V
    Turned every accessory on, 13.7V

    Decided I'd disconnect and clean all the ground connections on the battery ground post.
    Hear some motor or something running in the headlight area when I removed one of the cables...?! Maybe adaptive headlights....

    Fired it back up, and also got a tranny fault which cleared after putting the car in gear...

    Went to the car wash, and when leaving, got an OBDII check engine light. I'll go read it...

    Sent from my SM-G965W using Tapatalk
  • March 2nd, 2019, 04:41 AM
    wungun

    Re: Charging system fault

    Quote Originally Posted by RABarrett View Post
    If this is the reading on the charger, I am curious where it will stop charging. I am also curious as to the battery voltage when completed. Ray
    It monitors the voltage, and if it keeps going up, I assume it keeps charging. When the voltage levels off, it's finished...

    It's a charger for my RV model car. It can charge/discharge/balance/storage LiPo, Lead Acid, NiCd, Nickle metal hydride batteries...

    According to my meter, the display voltage is a tenth and a half higher on the charger...

    Stopped charging and the battery read 13.07V...
    13.06V

    Im assuming a small surface charge showing...
    Tossing it back into the car this morning...
    Will report back...

    Sent from my SM-G965W using Tapatalk
  • March 1st, 2019, 05:24 PM
    RABarrett

    Re: Charging system fault

    If this is the reading on the charger, I am curious where it will stop charging. I am also curious as to the battery voltage when completed. Ray
  • March 1st, 2019, 02:19 PM
    wungun

    Re: Charging system fault

    Quote Originally Posted by RABarrett View Post
    That may be a good thing. If the battery was discharged, and with everything on, the alternator is keeping up with all of the demand. This may have been a BCM response to a low battery. If the voltage drops below a certain level, the BCM will send a disconnect command to protect the battery, and will send a reconnect command when it receives a signal from your fob. Let's see what this situation precipitates. Ray
    Interesting...
    They really put a lot of engineering into these cars, and it shows everywhere you look.

    I can imagine the load the car/charging system is being put thru, with this weather! Heavily loaded...

    So, battery is out and being charged as we speak.

    Sent from my SM-G965W using Tapatalk
  • March 1st, 2019, 06:38 AM
    RABarrett

    Re: Charging system fault

    That may be a good thing. If the battery was discharged, and with everything on, the alternator is keeping up with all of the demand. This may have been a BCM response to a low battery. If the voltage drops below a certain level, the BCM will send a disconnect command to protect the battery, and will send a reconnect command when it receives a signal from your fob. Let's see what this situation precipitates. Ray
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