Trying to help a buddy get his boat fixed after it randomly died on him idling out of a cove. Now he has no spark at any of the cylinders. It was running just fine, then it just went off. No sputter or anything, just off. This guy is a stickler when it comes to maintenance and the boat hasn't had so much as a hiccup since he got it.
2002 Mercury 200 EFI 2.5L
Checked stop circuit including ignition switch, neutral & kill switch. All good. Plenty of oil. All fuses on side of motor are good.
-Key to on: No beep. No fuel pump. Dash lights come on.
-Key to on and wait 10 seconds: Sounds like fuel pump kicks on and solid alarm sounds. Alarm and pump stays on until key is turned off. Fuel will continue to prime for a few more seconds after key to off and then stops.
-Key to crank position: Engine turns over but has no spark. Tach is getting a reading during cranking.
Took it to a mechanic that said he would scan it for him at no charge. Scan tool won't connect. Told it was probably a bad ECM.
Is there anything else we can check before he starts throwing parts at this thing? I have no reason to doubt the mechanic, I just want to check everything we can before he shells out that kind of coin.