Smartcraft Gauge Faults

Electrical and electronic topics for small boats
JPTL
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Joined: Wed Jun 09, 2021 12:36 pm

Smartcraft Gauge Faults

Postby JPTL » Wed Aug 03, 2022 1:41 pm

On twin Optimax 150-HP engines the Smartcraft tachometer gauge for the Port engine seems to be working well with no faults, however for the last year,the Smartcraft tachometer gauge for the Starboard engine has had miscellaneous faults:
    trim
  • water temperature
  • oil level
.
The oil level fault wasn't present last year. This year while de-winterizing and before launching, I topped off both engines' remote oil tanks. I filled the tanks to the top of the filler neck and there was an audible GLUG-GLUG GLUG from air gurgling to the top of the filler neck. Apparently I shouldn't have filled to the top of the neck, but what's done is done.

After starting the engines on a hose adaptor, the Starboard engine Smartcraft tachometer gauge showed an oil level fault.

A "center gauge " reads 0.0.

I followed the bleed procedures for the under-cowling oil tank three times, but got no remedy.

I still get the OIL LEVEL FAULT on the Starboard engine Smartcraft tachometer gauge and also on a "center gauge " with a reading of 0.0 for Starboard [oil tank] level; reading for Port [oil tank] level is 2.5 gallons.

Since there's a specific gallon reading, I'm assuming that the oil tanks have a level sensor.

There is a noticeable amount of pressure in the oil tank when unscrewing the cap after operation. I assume this is normal, but maybe not.

Assuming there are sensors and connectors for the tank level for the oil tanks,

Q1: should I be troubleshooting a sensor?
Q2: should I be troubleshooting a connector?

Q3: is the remedy to recalibrate the Smartcraft gauges?

Q4: what is the procedure to recalibrate a Smartcraft gauge?

--JP
2000 Conquest 23

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Phil T
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Re: 2000 Conquest 23 Smartcraft gauge faults & questions

Postby Phil T » Wed Aug 03, 2022 3:19 pm

You should have a skilled Mercury mechanic run the diagnostic codes on the engine in question and also test the oil sensor that is throwing a code.
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jimh
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Re: Smartcraft Gauge Faults

Postby jimh » Fri Aug 05, 2022 8:40 am

JPTL wrote:There is a noticeable amount of pressure in the oil tank when unscrewing the cap after operation. I assume this is normal, but maybe not.
I believe that existing of a positive pressure in a Mercury remote oil tank is normal.

In the Mercury oil system a remote oil tank usually has two hoses connected to the tank. One hose is for the oil to flow toward the engine. The second hose delivers pressurized air from the engine to the tank in order to push the oil toward the engine. The tank must be maintained air-tight.

The pressurized air from the engine is developed from crankcase pressure via a check valve.

There is a very detailed description of how the Mercury oil system works in an article in the REFERENCE section See

Mercury Automatic Oil-Gasoline Mixing System
https://continuouswave.com/whaler/refer ... ction.html

jimh
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Location: Michigan, Lower Peninsula
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Re: Smartcraft Gauge Faults

Postby jimh » Fri Aug 05, 2022 8:51 am

JPTL wrote:Assuming there are sensors and connectors for the tank level for the oil tanks,

Q1: should I be troubleshooting a sensor?
Q2: should I be troubleshooting a connector?


Your assumption that there are fluid tank level sensors in the oil tanks can be tested by making a close visual inspection of the oil tanks. If there is a sensor, it will be electrical in nature. An electrical sensor will need two conductors to carry its signal to the instrumentation device.

It would be completely expected that if there is an electrical circuit from the tank to the instrument, where will be a connector or connectors in the path. The sensor would not be directly and permanently wired to the instrument.

JPTL wrote:Q3: is the remedy to recalibrate the Smartcraft gauges?

Q4: what is the procedure to recalibrate a Smartcraft gauge?


From your narrative the Port engine oil tank level appears to be working normally. On that basis a recalibration does not seem to be needed for the Port engine oil tank level sensor.

From your narrative the Starboard engine oil tank level no longer works properly. It is unlikely that the cause was a change in the internal firmware of an electronic gauge that has altered the calibration. More likely, since the reading is now shown as zero, the problem is a fault in the sensor, or a fault in the connection of the sensor to the instrument, or a fault instrument.

In systems in which there are two of everything, diagnostic testing can sometimes be done by swapping components. For example, you could test by changing the connection of the oil tank level sensors. Swap the Port and Starboard engine tank level sensor connections. See if the fault follows the tank or stays with the instrument. This will give you further insight into the cause of the problem.

If you perform that test, report the results and further advice can be offered.