I don't understand that part. Why does it need to be in maintenance mode? Why can't you just hook up the timing light and point it at the balancer and then run the engine from idle up to ~3,000 RPM? Even if you used an "old school" timing light without an advance feature you might have to make some marks on the balancer if there's not a good timing indicator on the block (that would show a variety of timing positions like the old engines had)....I know the data from the ECM says it’s advancing but I can’t test that with it running due to it needing to be in maintenance mode which negates the electronic advance in order for the timing light to give me a reading from the crank.