posted 01-15-2015 11:45 AM ET (US)        

SYSTEM CHECK WARNING LAMPS

The System Check instruments contain four warning lamps or status annuciators. The four lamps are marked:

--NO OIL

--WATER TEMP

--CHECK ENGINE

--LOW OIL

OLDER ENGINES

In the c.1996 engines, the various sensors in the engine that monitored the conditions and signaled alarms were wired directly to the system check harness. There were four sensors:

--a oil pulse sensor in the Oil Mixing System (OMS) pump (NO OIL); if the pulse sensor did not detect a pulsed flow of oil that was occurring at a rate proportional to the engine speed, it signaled an alarm;

--a temperature sensor with preset switch closure threshold on the cylinder head (WATER TEMP); if the engine temperature exceeded the fixed threshold, it signaled an alarm;

--a vacuum sensor with a preset switch closure threshold in the fuel supply line (CHECK ENGINE); if the vacuum in the fuel line exceed the threshold, it signaled an alarm;

--a float level sensor in the oil reservoir (LOW OIL); if the oil level fell below the float switch fixed level, it signaled an alarm.

When any of these sensors detected an alarm condition, their electrical circuit closed to ground, and this electrical signal triggered various actions. The signals caused the associated lamp on the System Check gauge to illuminate to warn the operator. The signals activated an aural alert sounder to warn the operator. And, in the case of the temperature sensor, the signal was also able to activate the S.L.0.W. protection circuit in the engine to limit engine speed to about 1,500-RPM.

E-TEC ENGINES

When Evinrude introduced the E-TEC engine in c.2003 they maintained compatibility with their System Check Tachometer and System Check gauges. The E-TEC engine continued use of the MWS wiring, and a connector was provided for connecting a System Check gauge.

While the E-TEC engine maintained compatibility with this system, the manner in which the various signals in the MWS harness for the System Check gauge was changed. The signals no longer originate directly from the various sensors. Instead the sensors are connected to the engine mangement module (EMM). The EMM interprets the sensor status, and the EMM generates the warning signals on the four lamp circuits. The condition in the E-TEC engine which will generate one of the four warning signals are notably different, and many more sensors are employed. As a result, interpretation of the four warning lamps is different with the E-TEC than with older engines.

Also, the EMM of the E-TEC can stop the engine from running and prevent it from being restarted. This is a notable change from System Check. In the prior system, the operator was responsible for evaluating the warning indicators and deciding to stop the engine, and the only alarm condition that affected engine operation was the S.L.O.W. engine speed limit invoked when the temperature was overheating. Now the EMM can force the E-TEC to shut off if the alarm condition warrants.

The EMM Operator's Guide explains the meaning of the System Check instrument's four alarm indicator lamps, but it is useful to review it:

NO OIL indicates an oil delivery problem. The sensor is part of the Oil Injector pump. When this alarm occurs, the engine enters Speed Adjusting Failsafe Electronics or S.A.F.E. mode. In S.A.F.E. mode the engine speed is limited to 1,200-RPM. The engine can be run for as long as five hours in this mode without oil. This is intended to provide a get-home feature.

WATER TEMP (sometimes shown as HOT) indicates an overheat condition in either the engine or in the EMM itself. This is a notable change from the previous system. In addition, this indicator can be shown in two modes: flashing or continuous. If the indicator is flashing, the condition is dangerous for the engine to continue running. The EMM shuts down the engine completely. If the indicator is continuously illuminated, the engine enters Speed Adjusting Failsafe Electronics or S.A.F.E. mode. In S.A.F.E. mode the engine speed is limited to 1,200-RPM, but the engine can continue to run.

CHECK ENGINE (sometimes shown as FAULT or CHK ENG) indicates a variety of other fault condition in the engine. There are three modes. A flashing light indicates a problem related to the fuel system. The E-TEC will be shut off by the EMM and cannot be restarted. A continuous light with S.A.F.E mode indicates an engine problem, but the engine can continue to run at reduced speed while returning to shore. A continuous light with no S.A.F.E. mode indicates a problem has been detected which will require further investigation by a dealer to resolve as soon as possible.

LOW OIL indicates the oil level in the reservoir has fallen below about one-quarter-full.

MORE DETAILS

The relationship between various engine fault conditions and which System Check annunciator lamp will illuminate is given in the SERVICE MANUAL for the E-TEC engine in a detailed chart that maps approximately 150 fault codes identifications to illumination of a System Check lamp.

Further insight into engine faults can be gained by interpretation of the EMM LED indicator lamps. The functions of these lamps in also explained in the SERVICE MANUAL.

SUMMARY

posted 01-21-2015 02:49 AM ET (US)         

Jim,

posted 01-22-2015 03:08 PM ET (US)         

I'm glad that you see the humor in my reply as I see the same in yours.

In the industry, a switch in a device that only turns a circuit on and off. A sensor is a component that sends a variable signal depending on the environmental conditions. For example a temp sensor would indicate to an EMM what the temperature is at the moment and if it changes. A temp switch would only signal an on or an off state when a pre-determined temperature activates it.

A pressure sensor would indicate the current reading and would change its signal as the pressure varied. A pressure switch would either turn on or off, depending on its design, when a pre-determined pressure is applied to it.

posted 01-23-2015 10:48 AM ET (US)            

Also in the earliest days of these sensors, there was a wired logic arrangement of them so that an aural alert would be actuated if any of the switches closed. I think that logic moved into the System Check gauge itself in the post-1996 MWS era.

posted 01-23-2015 01:47 PM ET (US)         

quote:

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The most significant difference in the operation of the System Check warning lights in the E-TEC engine compared to older non-E-TEC engines occurs in the CHECK ENGINE warning lamp. Previously that lamp only signaled a narrow range of conditions. In the E-TEC the CHECK ENGINE can be any of dozens of conditions of concern.

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