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1825 Views 5 Replies 4 Participants Last post by  Deafsoundguy
I was reading more about the ELR and came across the MSD. I haven't ever heard that term before and the document doesn't even describe what that means but it's the Master Serviced Disconnect for terminating your high voltage battery to the rest of the car. It is located right behind the console compartment armrest beneath the console pull-away. The document states that it should be replaced every 45,000 miles... wow. I thought "what the heck for?". The more I think about it, the only reason I could see is that maybe that much current through that connector is pitting the contacts via small arcs over time. I see this in a micro form on all my audio stuff where power amp output has to go through small connectors.

I thought maybe some of you may like that info. Line art Drawing Auto part Coloring book

I also found an interesting document, 3 pages of PDF that has some good info, as well as shows the car chassis is 80% steel and designed for quite a whallop. I bet if that was aluminum... well maybe not as strong but think how much faster the ELR would be if that weight was out of the car.... Probably way faster than the i3, which has the same performance time (2016 ELR). I know from owning the i3 that the BMW was highly sensitive to weight. With just me in the car it would go pretty quick but add even a single triple cheeseburger eating American passenger and you would really notice the car not liking the weight - God forbid 4 people...

I tried to attach this PDF about the ELR and electrical info for first responders, but the PDF file size it too big. Heres the link to the GM technical college 3 page info:

Hope someone will enjoy the info and pics...
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What's interesting is that the Volt Maintenance Schedule (at least for my 2014) doesn't say anything about replacing the MSD at certain intervals. I wonder if the extra power that the 2016 ELR can draw from the battery makes the regular replacement necessary, if it got left out of the older Volt manuals, or if they changed their minds about regular replacements along the way.

Has anyone with more than 45,000 miles on their car ever had the ELR MSD replaced? From what I've read, the service technician can't just pull it out and pop in a new one. They have to reprogram/reactivate the various computer systems, essentially like what happens after the airbags deploy and all the high voltage systems shut down for safety.
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