I don't think it can be repaired by ourselves or by any general technician. Please visit authorized servicer for the repair or for replacement. I don't think that can be repaired if anything is major.
I will suggest to get the key and relay for each electronics checked, Ritz face a major problem with it's relay system.
A faulty ecm can cause the vehicle in reduction of efficiency power and acceleration. it's better to change
As you are aware that there are 5 gears in RITZ all gears will be shifted as per the momentum of vehicle by and large all gears will be shifted less than 2000rpm however if any steep hill comes and you are in between and if you are on 1st gear definitely it crosses 2000rpm as you have to apply more acceleration , further regarding mileage i assure you on highways for RITZ Petrol gives 18 plus with AC , you better travel the final gear between 80 and 100 KMPH AND TRY TO SWITCH OVER TO 4 OR 5 TH GEAR WITH OUT LOSS OF TIME ,definitely it will help in getting more mileage ,check tyres pressure otherwise mileage will fall
I HAVE FOUND OVER MY EXPERIENCE THAT IF I DRIVE SOMEWHERE AROUND 60 TO 80 KM/HR ALMOST CONSTANTLY IT IS GIVING ME NEARLY 20KM/LTR OF PETROL. HOWEVER THIS IS EASIER SAID THAN DONE IN BANGALORE CITY WHERE I GET BETWEEN 15/16 KMPL. EVEN WHEN I DRIVE ON STATE HIGHWAY BETWEEN BANGALORE AND MYSORE I GET AROUND 17/18KMPL BECAUSE I DRIVE AT 110/130 KM AND AND CHANGE GEATS Quite often
U can upshift at lower rpm also if its a petrol. Instead of rpm go for speedometer reading.0-10 1 gear, 10-20 2nd,20-30 3rd, next 4th & at 50 , 5th gear. I have an rpm meter i hardly watch it while driving. In any case good driving habits like gentle start gradual acceleration & anticipated braking rather than harsh braking will give u a good mileage. City mileage is 12 for Ritz petrol & highway is 15
