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May 26, 2016, 03:26:40 pm

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Author Topic: MIL Code Temperature Sensor  (Read 184 times)


  • Neophyte
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MIL Code Temperature Sensor
« on: February 20, 2016, 07:01:28 pm »
Hi all, RE newbie here.  I bought a new EFI Classic last week and I have done around 190km so far.  Twice when riding for more than 30 minutes or so the MIL light came on and stayed on.  Stopped and let it cool down and all was well.  The MIL code shows 1 long 1 short - temperature sensor problem

Does this mean the engine has overheated?  Oil level is where it should be, just above the middle of the sight glass. Ambient temp on those days was around 27C


  • Grand Gearhead
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  • "But it's a dry heat here in Arizona
Re: MIL Code Temperature Sensor
« Reply #1 on: February 20, 2016, 10:06:59 pm »
Assuming you were riding real easy without using a lot of throttle or high engine speeds, most likely, the temperature sensor is malfunctioning and sending incorrect data to the computer.

If this happened right after startup I would say the problem is with a loose connector.

Because it waited until the oil was hot before it activated it says the sensor is screwed up.

These UCE powered RE's usually run pretty cool and I can't say I've ever heard of the oil getting so hot that it would cause a problem.

The problem should be covered by the warranty so, take the motorcycle to the dealer and ask him to fix the problem.
He'll probably just replace the sending unit and send you on your way.
2011 G5 Deluxe
1999 Miata 10th Anniversary


  • Neophyte
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Re: MIL Code Temperature Sensor
« Reply #2 on: February 20, 2016, 11:40:51 pm »
The oil temperature sensor is a variable electrical resistance the value of which depends on the detected temperature: only serves to adjust the fuel injection as a function of the engine temperature.
The greater the tempertura and the lower the electrical resistance of the sensor.
From the checks that I made I know that only a very high resistance (open sensor circuit) causes MIL BLINK, then only the circuit malfunction causes MIL BLINK and not high engine temperature


  • Grease Monkey
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Re: MIL Code Temperature Sensor
« Reply #3 on: February 21, 2016, 08:08:15 am »
Probably a circuit or sensor issue as has been stated. My advice would be to mention it to the supplying dealer with a view to getting it fixed at the first service. FWIW when my "blink test" suggested that the crank position sensor was defective it turned out to be a disconnected throttle position sensor, when the dealer checked it on the proper Keihin tester. I doubt that running it in the current state will harm it as these motors run pretty cool. Sensors are cheap and prone to failure early on or last almost indefinitely in my experience.


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Re: MIL Code Temperature Sensor
« Reply #4 on: February 21, 2016, 03:14:03 pm »
Thanks all for the replies. 

I agree that it seems like the temp sensor is at fault.  I measured its resistance at cold this morning - 286ohm with digital VOM.  I'll measure again this evening after a bit of a ride. 

Just found the range of temps/resistances in the Service Manual, so it looks like mine is out of spec given that ambient temp this morning was around 15C
« Last Edit: February 21, 2016, 03:46:42 pm by jvb »