2005 115 4s EFI Alarm Issues

[ady001]

Hi Guys, having a problem with my alarm system.

No Beep when ignition turned on. With Kill Switch enabled, the alarm sounds after turning the key. I shorted the water temp sensor wires (yellow/black to black) with ignition on and no alarm. I have a new water pump and the oil is good but I am worried that I have no protection should I overheat or lose oil. The motor runs great.

Am I missing something?? I'm thinking the ECU maybe at fault because I cannot cause a beep at the temp sensor. Any clues?? Thanks

 

[Maxz695]

Re: 2005 115 4s EFI Alarm Issues

you may have shorted the alarm sensor out. just a thought there was a post earlier about changing over to a water temp pressure sensor (PSI Gage and hose requiered but More reliable) if your engine doesn,t have the thermostat. To me sounds like the temp sensor might be bad. does it still beep when the key is turned on?or just when you try to start it (If I read correctly) also there may be 2 sensors one is an oil injection pump alarm not sure if this engine you have is oil injected ?

 

[Faztbullet]

Re: 2005 115 4s EFI Alarm Issues

The oil and water temp are sensors not senders so shorting them will not set off horn. The water temp and oil sensors sends varying voltage to ECM to let it know if its overheating or pressure has dropped..

 

[jeffersondodson561]

Re: 2005 115 4s EFI Alarm Issues

With Kill Switch enabled, the alarm sounds after turning the key.

That alarm when you turn the key is letting you know that your emergency stop switch is active.

 

[ady001]

Re: 2005 115 4s EFI Alarm Issues

"That alarm when you turn the key is letting you know that your emergency stop switch is active." Yeh got that, I tried that to check the wiring from the ECU to the horn, so that looks okay. This is the only beep I get at present.

To Recap; There is no beep when I turn the ignition on - so no self test. This worries me that the protection circuit is not working. I removed the plug from the water sensor and shorted the 2 wires - at the plug not the sensor - I then turned on the ignition and did not get an overheat warning.

" The water temp and oil sensors sends varying voltage to ECM to let it know if its overheating or pressure has dropped The water temp and oil sensors sends varying voltage to ECM to let it know if its overheating or pressure has dropped" Does this mean they are not switches?

So is there another way of testing the circuit? I can find nothing on the web and my dealer can't help me. With an ECU being over a grand, I want to be sure I need one first.

 

[portd]

Re: 2005 115 4s EFI Alarm Issues

Was there ever a beep when you turned the key on ,my 2002 115hp efi fourstroke does not have a self test when key is turned on . i thought when i searched it found that some years and models dont have self test ,

 

[Faztbullet]

Re: 2005 115 4s EFI Alarm Issues

I removed the plug from the water sensor and shorted the 2 wires - at the plug not the sensor - I then turned on the ignition and did not get an overheat warning.

And you wont...the ECM is looking at a resistance voltage from sensor, if sensor tells ECM that oil pressure or temp has exceded set parameters it will: (A) shut off fuel/ignition/timing till affected sensor says it normal (B) sound operator alert horn

 

[jeffersondodson561]

Re: 2005 115 4s EFI Alarm Issues

This worries me that the protection circuit is not working.

Is this your first 4 stroke? If you have a problem you will know from possible alarms or engine performance. Remember you are in a boat possibly miles offshore, it is the motors job to get you back safe, the laywers made sure of that.

 

[ady001]

Re: 2005 115 4s EFI Alarm Issues

And you wont...the ECM is looking at a resistance voltage from sensor, if sensor tells ECM that oil pressure or temp has exceded set parameters it will: (A) shut off fuel/ignition/timing till affected sensor says it normal (B) sound operator alert horn

Starting to make sense now. So it's a thermistor and not a switch. Any ideas on the valid resistance ranges ?? I can get a pot and try it out.

Anyway, I'm starting to doubt my memory that it did indeed beep when I turned the ignition on. can anyone with an 05 115 4s EFI confirm this??

 

[ady001]

Re: 2005 115 4s EFI Alarm Issues

So I've done some checks:

With the engine cold, the sensor resistance was around 4K ohms. I ran the endine in idle for about 15 mins to warm up, shut her down and checked again. 1.1K ohms. After 30 mins to cool down the resistance was 2.2K ohms. So its a negative going thermistor and not a switch. I shall try and get a0-5K ohms pot and see if I can get the alarm to sound. I shall post the results. I don't want to mess with the oil sensor just yet as it's a little tricky to get at.

 

[jeffersondodson561]

Re: 2005 115 4s EFI Alarm Issues

I would get a mega ohm resisitor if your trying to the alarm to sound.

 

[ady001]

Re: 2005 115 4s EFI Alarm Issues

I would get a mega ohm resisitor if your trying to the alarm to sound.

?? The resistance at the sensor went down when the temperature rose. Surely I would need a lower resistance?? I shall get a pot and try different values in the same range I measured at the sensor.

 

[sxmerc]

Re: 2005 115 4s EFI Alarm Issues

There is NO self check horn on this motor. If you get horn with kill switch activated, then your horn is working. If this thing over heats, over revs, or loses oil pressure, it's going to go into guardian mode whether or not the horn is working. Put the tools away, and go boating!

 

[jeffersondodson561]

Re: 2005 115 4s EFI Alarm Issues

Your right, negative coefficient resistor, then just ground to the block.

 

[jeffersondodson561]

Re: 2005 115 4s EFI Alarm Issues

Your right, negative coefficient resistor, then just ground to the block.

Ok now that I have my head out of my @ss, got to thinking if you ground wire to block ECM will receive REF HI fault. No big deal, just next time it is in the dealership and if they say to replace your temp sensor just tell them you got some bad advice, sorry here you go...

So you would need a 190 ohm resistor to trigger 212 degrees.

 

[ady001]

Re: 2005 115 4s EFI Alarm Issues

Awesome, Thanks for that. I shall try and check it out this weekend and post the results.