Hello everyone.
I am MK.
I am writing this translator and an inexperienced English proficiency.
Please note that the sentence is awkward.

Recently, Moto camping with friends.

There was no problem when going.
There was a problem returning.

Release the throttle and drive down the engine with the gaer warning light on.
The feeling that the gear is fixed to the bottom.
And then back to nomal driving.
Then the throttle was released for the traffic signal, but the ignition off and the service light were on.

Restart did not work well.
When the warning light is not illuminated during the symptom, both the output and gears work properly.

I just came home and checked the error code.

DSB08
ECU54

I just came home and checked the error code.
Even if the self reset function is initialized, the ECU 54 does not disappear.
I searched for ECU54 error but could not find it.

Currently, it does not start, and only the sound of the start relay sounds like the discharge of the battery.
I tried to jump the battery and started the start motor, but the start does not take place.
The battery was normally pointing at 12.4v and dropped to 6 ~ 7v when the start motor was running.
It has recently been discharged and has been charged using the charger, but it is now.
There was a discharge before the moto camping, and it operated several hundred kilometers after charging.

My Mana has traveled 28,400km in 2008 year.
The belt and slider have been replaced at 27,400km.
Equipped with a Leo Vince muffler, the external diameter 91mm has been working to reduce the sound.

Does anyone know symptoms such as my mana or how to fix it? Ask for help.
Please help me...!