Mitsubishi Pajero fuel filter indicator lamp and airbag indicator light doesn't go off

Normally the above lights go off few seconds after the ignition key is switched to ON position. The Pajero has been lying in the garage for 3 weeks in humid rainy weather. On turning the ignition key to on position I noticed that the above lights did not go off as usual. I started the engine and the lights still doesn't go off. Drained the fuel filter off some water and tried the ignition key again. Lights still doesn't go off.Switched everything off unplugging the battery terminals. No authorized Mitsubishi dealer within 100 km. Cleaned all earthlings the next day and put battery terminals in place and turned the ignition key. The lights went off ! I drove the vehicle for a few km. All was normal. Vehicle back in garage. Next day switch on the problem is back..Lights doesn't go off. Battery terminals taken out and tied together for 5 mins and put in place again. Ignition key switched on...Lights go off , all normal again. Drove the vehicle , all normal. Back in the garage for the night, battery terminals in place. Next morning switch on..Lights doesn't go off. Battery terminals again taken off, tied end to end for few minutes, and then put in place and ignition switch to on...Lights go off..All normal. Please help....This is a very well maintained relatively new vehicle since done only 70,000km.