smartcraft sensor fault

[julians]

The smartcraft display on my 2006 200 select witha 5.0 mpi is intermittantly telling me that is has detected a fault with the water pressure sensor. Every now and again it will flash up a message that cycles through the following texts, and when it is in the failed state, it wont let me rev past 4000rpm :-

'CHECK ENGINE'
'FAULT SENSOR'
'Water pressure sensor failure'

All vital signs are normal, so I presume its correct and the sesnor has actually failed rather than a bigger problem.

Does anyone know where abouts on the block the sensor is, so I can see if its a wiring fault or an actual broken sensor?

This is the second water pressure sensor failure, the first one failed in the first year of ownership and was replaced under warranty.

As an aside, does anyone know how the ecu detects that the sensor has failed? and what is water pressure information used for, it seems like a pointless sensor on the face of it.

 

[Henry Boyd]

You should have received Mercruiser manuals with your documentaion when you got the boat. There should be a diagram of exactly where the sensors are in one of them. I know there is in the 496 manual (don't recall which one).
Henry

 

[julians]

The only mecruiser manual I received is the engine operation manual, which describes how to use the engine, and how to do basic maintenance (like change the oil), it doesnt describe the location of the sensor.

From googling though, it appears the sensor is screwed into the power steering cooler.