Mutt p0117 coolant temp sensor promlem

Hyphagon · L Plate Warrior Joined: 31 Jan 2024 Karma :

Hi All,
I have a 2019 Mutt Mongrel 125cc which a uses version of the Suzuki GN125. The engine light came on even though it is riding ok so I plugged in my Motopower MP69038 OBD2 reader and it's come up with 2 faults codes - both the same! P0117 - Engine coolant temperature sensor 1 circuit low. But it's air cooled! So I've got 3 ideas:

A) my reader is showing the wrong code and it's a different problem but any ideas on how I know what?
B) the wiring for a coolant temp sensor is present just not used and it's now malfunctioning.
C) Something else!

I'm now a little bit out my depth as used to classic cars without ECUs so hoping someone can point me in the right direction.

Cheers

WD Forte · World Chat Champion Joined: 17 Jun 2010 Karma :

My money's on it referring to the temp sensor on the head
Not familar with the GN ones but the YBR125 sensors
will have resistances around 2K ohms at 20C to 200 ohms at 100C which is kind of typical so would use that as rough guide when testing it.
If it stays fixed in any state when the temp changes, it's broke

BTW if the ECU detects a fault in that sensor, it will keep running
as its not critical, but will usually dial in a ball park figure to work with when calculating fuelling and ignition
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Hyphagon · L Plate Warrior Joined: 31 Jan 2024 Karma :

Hi WD Forte, thanks for the reply.

I think you may be right. After a quick lap round the block so engine cold enough to still touch the sensor showing 9 ohms. I then left it unplugged while I ran the test again and this time the read error code was p0118 - Engine coolant temperature sensor 1 circuit high. So this is indeed the sensor causing the faults.

Only weird thing is when I read live data with the OBD2 reader it was showing ETC as 10oC before the ride and currently 30oC which appears correct.....

But guess I'll get another temp sensor and try that out.

Cheers

A100man · World Chat Champion Joined: 19 Aug 2013 Karma :

WD Forte · World Chat Champion Joined: 17 Jun 2010 Karma :

Engine is K157FMI a GN125 clone to euro 4 spec as used on a shit ton of other chinese made bikes
Mutt just bolt on hipster cosmetic stuff to make it more 'cool'
(and expensive) but no better in terms of performance or longevity
I believe the KY superlite uses the same engine.
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bikers smell of wee