[aloysiusokino]

Thanks. How can I locate the 12volt AGM and it's plugs or cables? Is it the black negative cable on the battery terminal? Also is the AGM different from the APM?

 

[TSquare]

Thanks. How can I locate the 12volt AGM and it's plugs or cables? Is it the black negative cable on the battery terminal? Also is the AGM different from the APM?

The 12 volt AGM is the 12 volt battery in the back under the hatch floor. The APM is the Auxiliary Power Module. It takes the place of the alternator in an ICE car. There is NO alternator in a Volt.

 

[aloysiusokino]

Hi everyone. When I remove the negative of the AGM battery the vehicle goes off instantly. Is that a confirmation that the APM is not charging?

 

[bentbiker]

Hi everyone. When I remove the negative of the AGM battery the vehicle goes off instantly. Is that a confirmation that the APM is not charging?

You've proven that the AGM is not charging the 12v battery. What you don't know is whether the APM is bad or whether the APM is not receiving the power it needs to operate. Do you know whether the logic circuits of the APM use the 12v battery? If so, there could be a fuse feeding it. Or, one of the connections to the APM could be loose or a cable could be broken. Too many possibilities for me to recommend swapping out parts.

When you measured the 13v with the car powered off, you didn't have the EVSE plugged in by any chance did you? That is a bit high for a battery sitting idle.

 

[aloysiusokino]

Hi everyone, I am glad to tell you my volt is back on the road. I took your advice and bought the APM on eBay and it was fixed yesterday. All codes cleared and vehicle is working perfectly. Thanks again

 

[profkwame]

Hello Aloysiusokino, I have this exact same problem on my 2011 volt. I have also replaced the APM with one purchased from ebay but the "Service battery system" alarm remains together with all the symptoms you describe above.

I wanted to know if you did any soft configuration or programming after physically replacing the APM. I also do not have a service station here in Ghana and can only hope to get this fixed myself. Any helpful information will be appreciated.

Tony