Mercury 150 optimax alarm

[tleal]

I get an alarm if I run my 2001 optimax a little faster than trolling, or if I'm trolling and then decide to get my boat on plane. If I shut the motor off, restart and get boat on plane, its fine, or if I just run at trolling speed its fine. I took it in to the marina, and they said the computer (I can't remember the 3 letter name for it) was giving bad information, and sometimes no information at all. To replace the card/computer would be $1,500. That would just help them to determine to real problem. Any ideas?

[truble]

is it low oil or temp alarm,,i had a 150 opti that was mounted high on the transom and at speed or certain slow runing with bow up the low water alarm would go off,,ended up was just air around top water holes in cav plate ,,filled top holes with epoxy and never happened again,,but if it resets after re starting,,it could be an ecu black box problem,,ask if they have a s/h 1 you can borrow,,

[Mollers]

Mine'll do it occasionally. I turn the ignition off and on again and it's fixed.

[tleal]

What is "s/h 1"

[Mollers]

Originally Posted by tleal

What is "s/h 1"

Second hand one.

[Searider]

Mine used to get hot when running just above idle. New water pump, not just impeller, sorted it.

[tue]

Does your dealer not have the diagnostic software for the engine? They should be able to connect up to a laptop and then go for a run in the boat and determine which sensors are at fault or if it is an ECM problem.

[tleal]

They said the ECM card was giving bad information. He said that his merc dealer may be able to re-load the software. Has anyone heard of that ever working. Its expensive to replace.

[tue]

Not sure if he will be able to re-load the software. There is a function on the laptopsto enable us to re-map the ECM but it is currently disabled for the dealers use , unless they are now allowing its use in the US?

[tleal]

My dealer is sending the PCM to Mercury for them to re-flash the card. I'm not sure what that means, or how often it works