Engine warning light

I'm not sure if this the right place to post this but I am having trouble with my Yamaha MT-125 2017. Few months ago I ended up braking down due to corrosion inside the alternator socket which led to a flat battery. I had RAC clean the corrosion and fix the issue but I ended up with a engine warning light. I have contacted Yamaha and they believe it's displaying due to low voltage when I broke down and just needs resetting (doesn't display an error under ODO) but.. the closest Yamaha Dealer is around 80 miles (I live in cumbria). The bike runs perfectly fine without any issues either.

I am wondering if someone has encountered this issue before or knows a way of resetting this without going to a Yamaha dealer.

Just out of curiosity, what does this light actually warn you about ? In other words , what imminent engine malfunction(s) does it draw your attention to ? My bike has an oil pressure warning light and a high temperature light so what use would a general engine warning light be ? As I say , just curious.

6. Engine trouble warning light

Doesn't really give you much information as to what it's aimed at but on the left of the display it shows temp and oil warnings when needed so it's not of those. It doesn't display an error code which it would if there was an actual fault occurring.

https://www.themotorbikeforum.co.uk/download/file.php?mode=view&id=21346&sid=8fdca1d1b5498cdcaba52a98cb6d3c99

6. Engine trouble warning light

Doesn't really give you much information as to what it's aimed at but on the left of the display it shows temp and oil warnings when needed so it's not of those. It doesn't display an error code which it would if there was an actual fault occurring.

https://www.themotorbikeforum.co.uk/download/file.php?mode=view&id=21346&sid=8fdca1d1b5498cdcaba52a98cb6d3c99

Thanks for the reply , now I'm even more curious. I'll have to look into this myself. Sorry that none of this solves your issue .

I don't know the specifics for your bike but in general ECU engine management systems will store faulty code(s) when the engine management light is illuminated. Some systems will reset if you disconnect the battery for a while, many won't as the ECU has the capacity to retain codes whilst disconnected from the battery.

Your has a specific low voltage warning message but ECU systems aren't foolproof.

I'd try disconnecting the battery for say 10 minutes and see if that clears the code from the ECU. If it does all well and good, if not it will need diagnostic kit to turn the light off.

Many systems will store a code for a problem that is not current - so the light stays on even though the problem has been fixed. It's annoying but it makes the customer go to the dealer and frankly that's how many products work these days. Try disconnecting the battery first - you only need to remove the earth lead which is the always the one you disconnect first and reconnect last.

I'll give it a try and see if that works, if not I'll have to take it to a Yamaha dealer and get them to sort, just hope they don't charge me for it

You could just take the the bulb out

^^^

That would be an MOT fail nowadays.

The way to deal with this problem on cars is to buta n OBDII interface, plug it into the vehicle and a laptop.

Then using apropriate software you can read the fault code reset the system.

I bought one fro £!5 off ebay, it came with software the=at works on mnay cars, I have used it to reset lights on my daughters car and read information on my Mondeo.

Can you get similar that wrks on bikes?

I still don't get it , its a 125cc motorbike, so unless the engine is covered in all kinds of sensors ,how is this data collected ? I just can't see the point of a general engine warning light if you can't tell what it is warning you about . Apart from oil pressure and temperature what else could be monitored and why ?

I still don't get it , its a 125cc motorbike, so unless the engine is covered in all kinds of sensors ,how is this data collected ? I just can't see the point of a general engine warning light if you can't tell what it is warning you about . Apart from oil pressure and temperature what else could be monitored and why ?

Anything with fuel injection will have some form of electronic module / ECU to monitor fuelling, no matter what engine size. Some 125s simply refer to it as the FI light rather than ECU - on Suzuki 125s you can interrogate the FI module using a simple switch device (or a paperclip bridging the FI data port connections) and watch the FI light flash the relevant codes.

The MT 125 has a more sophisticated engine management system - the instrument panel will give specific details of low battery, oil change due, service intervals etc. So it's using a more complex ECU system. The usual things it will monitor are air flow, fuel trim, exhaust gases, air temperature, voltage levels, throttle settings, vacuum, whether the ash tray is full. It is annoying when they fit a system that doesn't tell you anything other than that the is (or has been) a problem. But it's like most things these days - they are designed to bring you back to spend more money in the future. I'll bet the dealer will charge simply to connect the diagnostic kit (which will have cost them a silly amount to buy) but it means you're increasingly stuck with main dealer servicing.

I use OBDII and manufacturer specific diagnostics on cars but since I run an older carb bike I don't have anything that work on bikes. My hunch is they don't use the same generic system as cars - though even then generic OBDII kits aren't always compatible with all cars. I've done a lot of work on Vauxhalls and even high end workshop diagnostic machines can struggle to read codes on some of them.

Brilliant answer , thanks for that . Seems like manufacturers are deliberately trying to stop owners learning the craft of motorcycle maintenance then. So even if you were to perform all service tasks you would still not be able to reset this annoying warning light unless you had access to diagnostic technology. You can tell I've never been able to afford a new bike ! Wouldn't want one anyway if this is the nonsense you have to put up with. I've just done a full service on my 97 ER5 and enjoyed every minute of it

You can reset the service light but engine faults seem more tricky.