Help Honda CBR250R MC41 temp gauge not showing

Discussion in 'Honda 250cc Singles' started by twofake, Oct 29, 2016.

  1. twofake

    twofake Active Member Premium Member Contributing Member

    Messages:
    10
    Likes Received:
    2
    Trophy Points:
    173
    Joined:
    Jul 5, 2015
    Gender:
    Male
    Location:
    Australia
    My Bike:
    Honda cbr250r,cbr250rr,rvf400
    Does anyone know how to reset the temp gauge on this bike so that it shows? It somehow disappeared on my bike that i ride as i was trying to work out why it didnt work on a project bike of the same type. That is, the project bike has no temp gauge showing and i was looking at my bike and unplugged the coolant sensor and when i re-plugged it, the gauge did not show up.
    I have looked at the pdf manual (thanks kiffsta) and in part 5 page 20-12 it shows to join Green/Blue to ground to check if this is working. I checked it and the reading is correct (meaning the gauge reads H with all bars lit. When the connector is re-plugged the gauge is not showing).

    Is there some sort of battery reset or something that i should do to clear the memory?
    Surely the Engine Coolant Sensor (ECT) cannot become faulty simply by unplugging it as it is a variable resistor that is affected by heat?
     
  2. twofake

    twofake Active Member Premium Member Contributing Member

    Messages:
    10
    Likes Received:
    2
    Trophy Points:
    173
    Joined:
    Jul 5, 2015
    Gender:
    Male
    Location:
    Australia
    My Bike:
    Honda cbr250r,cbr250rr,rvf400
    Problem solved.
    I tried battery removal and left it over night and that didn't fix it.
    I tried ECM removal and that didn't work.
    I tried resetting the coolant sensor as per you tube and that didn't work.
    Went for a ride today and there was no temp gauge at all when i left.
    As bike warmed up the gauge came on. Maybe the temp sensor has to be a certain degree to then reset the gauge to show up?
     
    • Like Like x 2
  3. thebeefsalad

    thebeefsalad Well-Known Member

    Messages:
    490
    Likes Received:
    301
    Trophy Points:
    273
    Joined:
    Feb 28, 2015
    Gender:
    Male
    Location:
    San Antonio, Texas USA
    My MC41 showed the temp the entire time I owned it. I'd be checking for a bad earth.
     
  4. twofake

    twofake Active Member Premium Member Contributing Member

    Messages:
    10
    Likes Received:
    2
    Trophy Points:
    173
    Joined:
    Jul 5, 2015
    Gender:
    Male
    Location:
    Australia
    My Bike:
    Honda cbr250r,cbr250rr,rvf400
    Thanks for the reply. What is very strange now is that the temp gauge completely disappears when the bike cools down . It is sort of like the resting temperature is now off the scale ? Meaning when the bike cools down, there is no temperature bars at all and when I run the engine for say a few minutes , one bar appears then two and it sits on three bars when it is warm.
    If it had a bad earth , wouldn't it not show anything? I think it really strange that all I did was unplug the coolant sensor and then replug it.
    I could try cleaning the socket but it does already appear quite clean.
     
  5. thebeefsalad

    thebeefsalad Well-Known Member

    Messages:
    490
    Likes Received:
    301
    Trophy Points:
    273
    Joined:
    Feb 28, 2015
    Gender:
    Male
    Location:
    San Antonio, Texas USA
    If the earth failed completely, sure... or it might show boiling temps *shrug.*
     

Share This Page