I just found out that if you press the on the hook button for a few seconds the HFL goes into diagnostic mode and a voice with a british accent will say system ok then an asian voice says the same thing in japanese. Not sure if anyone else knew this.

 

What hook button are you talking about?

 

OP's talking about the hangup button... if you hold it for a few seconds, the diagnostics prompt will tell you the HFL system is OK. the said trick was mentioned in the tsx easter egg thread many years ago.

 

I kinda thought this might be a repost. Well at least for a secondi thought i had found something new.

 

What if holding the button doesn't do anything? Probably means it is time to replace it? What about some of these battery disconnect or fuse pulling ideas?