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Check Engine Light / alarm before starting - 2004 8.1

T

tyrenta

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Hi all, 2004 Captains Choice 8.1 engine -- I'm getting a check engine light on my the port engine before starting when i turn the key. The boat is still layed up for winter so I haven't tried to turn it over yet; the last thing I did was winterize / change oil with fresh water from a hose and all seemed fine; I can't imagine this would be related, but also just replaced a bad tach on the same engine and don't recall getting the light/alarm when checking that tach with ignition power in the fall. I noticed the issue yesterday when checking to see if the new tach was getting signal.

Since the engine isn't running when getting the error, is there anything I can easily check for issues, or will I need a code reader (I don't own one) / mechanic to take a look?

Thanks for any advice
 
Check the manual. That's normal operation for 2007 models. "The alarm circuit has a “self” checking feature programmed into the system. This feature will momentarily light the “MIL”, and if equipped, sound the alarm for two short pulses upon initial start-up of the engine."
 
yes I know but it isnt the usual self-check -- the both the light and alarm remain on steady until I turn the ignition off again. I've never seen this before and the starboard engine does not do the same
 
Did the new tach work ok ? The loss of the tach drive is a indication of an ECM failure. All you can do is check the ECM connections until you get a code reader. If you want to gamble,you could swap ECMs with the good engine. But, you risk blowing it up.
 
rfdlou said:
Did the new tach work ok ? The loss of the tach drive is a indication of an ECM failure. All you can do is check the ECM connections until you get a code reader. If you want to gamble,you could swap ECMs with the good engine. But, you risk blowing it up.
Click to expand...

I'm still dry so can't turn the engines over yet, but the new tach seems to be working; I had sent the old one (VDO) to NSI for testing and they confirmed it was shot. I think the problem with my tach was caused by failing batteries / low voltage, which have now been replaced, though I could clearly be wrong about that it could have been purely coincidental.

Do you mean an ECM failure could have fried the tach, or just wouldn't send a correct signal to a good tach?

By checking connections, do you mean just the two ECM connection harnesses, or all connections on the wiring harness? Could it also be a bad fuse in the wiring harness to the ECM?

My last question -- since I don't have a code reader, are the CodeMate readers worth spending $50 on, or won't that help me much?

Thanks for the help
 
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