Re: Need ECM for mercury sport jet
Did you carefully check the wiring to the motion sensor? The TKS ECM continually monitors the operation of the motion sensor to assure that the oil pump is working. If there's a short or a bad motion sensor, then you would get the warning buzzer. Also the magnetic float sensor in the oil reservoir will cause the horn to sound as well. I'd make sure that I was positive that the problem wasn't in one of those before shelling out $500 for a new/used one. The problem could be internal to the ECM, but it might be worth checking. Good luck!
From the manual:
(TKS ECM)
The Turn Key Start Electronic Control Module (TKS
ECM) provides four major functions:
? Electrically controls the enrichment valve to provide
a rich fuel charge for starting a cold engine.
? Provides spark advance of 5 to start a cold engine.
IMPORTANT: Below 3,000 RPM the TKS ECM advances
idle timing 5 until the engine reaches
104F (40C). Above 3,000 RPM, the TKS ECM
does not affect ignition timing regardless of engine
temperature.
? Monitors and provides warning horn sounds for:
a. System Start Up Test
b. Low Oil in Engine Mounted Oil Tank (Magnetic float switch)
c. Oil Pump Drive Failure (Motion sensor on drive gear)
d. Over heat condition (cylinder head temperature)
? Provides engine over-rev protection by progressively
cutting off spark to ignition coils.
NOTE: There is no troubleshooting for the TKS ECM.
The engine will run without the TKS ECM. If the TKS
ECM is suspect, disconnect and run the engine to
systematically troubleshoot.
