Yamaha 25hp four stroke slow down mode

[dumb22]

I have a 2001 25hp four stroke yahama that the slow down mode comes on now and then,sometime you can run for 15min and then it might come on, go off and not come on again till next time out. The thremostate has been checked it is working fine,the oil sending unit is working as it should and the engine has good oil pressure.and the temp sensor has been cheked and it is ok.even when it is disconected the slow down mode will come on.the only thing left is th icm i hate to buy one witout knowing for sure because of the cost.is there anything else i should check and does anybody know of anyway to disable the slow down mode.