If they just care about the idiot light at key on, wire in parallel to the oil light. It will come on at start but turn off just after starting. (might be a better option). It could take quite a lot of work to properly resolve and as long as obd reader works you can keep track.

SES light is primarily for smog control the serious problems like loss of coolant or oil pressure have their own light. You will be find to check periodically with the reader

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)