water pressure sensor/oil warning buzzer

[boscoe99]

You might be surprised at all of the money that Yamaha US was throwing at this problem when first it reared its ugly head. Parts were being thrown at the motor (under warranty) right and left. No one understood what was going on so the advice to the dealers was "try changing this, no trying changing that".

The symptoms that were being seen just did not add up and did not make sense. Unfortunately, a failed sensor would manifest itself in one form one time and then in a completely different form the next time. There was no repeatable failure mode pattern.

Damn those rogue electrons.

[99yam40]

In light of the OP's report that the motor will not start with the failed sensor connected are you going to reconsider your comment?

I suspect that only Mitsubishi knows all of the various failure modes and the effects that they can cause to the motor. Probability of anything adverse happening (motor not starting or running for example) is more than likely extremely low but it apparently can still happen.

I really do wonder if the reference voltage is being dragged down by the WPS or the wiring to it. That may help in explaining what is going on. Without the readings we will never know for sure

[michaelmeseck]

i too would be curious to know. unfortunately I have very little knowledge when it comes to electronics. if you guys can describe to me what I need and need to do to check it I would love to do it. that way we could all learn a lot more from this ordeal...

[rodbolt17]

drat them stupid ECU's.
you would think they might tell a supposed tech the ref voltage was high or low.
stupid engineers at Yamaha actually thought trained techs would be working on the stuff.

all that highlighted bar on YDIS means is the ECU saw an out of range feed back.
doesn't mean a sensor failed.
mostly, just like in the auto world, all YDIS does is tell a tech whats NOT wrong.

[boscoe99]

The reality is that for every Yamaha master mechanic there are tens if not hundreds of non-Master Yamaha mechanics that have had some formal Yamaha training. For every non-Master Yamaha mechanic that has had some formal Yamaha training there are tens if not hundreds if not thousands that have had no formal training at all.

Computer savvy youngsters today that are willing to go into maintenance work are expecting systems diagnostics to do much more than marine ECU's currently provide. It would not be unreasonable for the system to perform a self check and provide a maintenance alert if and when reference voltages were not up to specification. Marine systems are weak compared to automotive systems and automotive systems are weak compared to aviation systems. Hell, a Boeing will monitor itself darn near continuously and send a radio message back to home base telling the mechanics what is wrong with itself. The airplane maintenance manual then provides a complete theory of system and component operation and provides details as to troubleshooting for problem verification. It will even specify which tools will be needed for the job. If you could see an airplane MM and compare it to a marine SM you would understand what I am talking about.

Yamaha may very well be expecting nothing but Master Mechanics to be working of their motors and structure the SM accordingly. However, the fact is there are not enough Master Mechs to do all the work. If this is so, then Yamaha is foolish. Just like in school, you don't teach to the brightest kid. You have to teach to the less than bright.

Yamaha either fails to understand, or refuses to accept, that lots of folks want to do their own maintenance. Why not give them the tools to do this particularly if it results in enhanced customer satisfaction with the product? Which would they rather have? A satisfied customer who can do his own work based on good maintenance instructions in an SM or a customer that is pissed off because his boat and motor had to sit at a dealer for a month or more, is dirty as hell when he gets it back, and more times as not the problem has not been fixed?

[tmann45]

Michael (or bosco or rodbolt), what water pressure readings are you seeing with this faulty sensor?

Are they far enought out of range to be used as a diagnostic?

If the reference voltage is out of spec, does that cause the water/oil pressure to be out of normal range? Does this show up on the gauge as an abnormal pressure?

[michaelmeseck]

the gauge itself usually reads full left at the low mark as if the sensor isn't working at all (or the pressure is low). *every* once in awhile it would kick on for a few minutes and read right at or around the middle mark, but that was very rare.