I tried the suggestion in Chilton's Manual. Take out the G-sensor, bring it to a Mitsubishi dealer and have it tested.
If there is something wrong with the G-sensor, you can always, buy one and change it yourself.
In my case, it worked. I did not even have it tested, just gambled.


Montero SR, 3.5 , 1995 model, ABS, Rear Differential Lock