2004 Chrysler Concorde Starting Problem

Electrical problem
2004 Chrysler Concorde 6 cyl Front Wheel Drive Automatic 90660 Kms
The Car is having starting problems recently and the engine warning sign is on. In order to start you need to keep the key turned and kept pressed for a while and then it starts. Also while changing the road lane if you give more gas then the gear knocks and then runs smoothly. The engine stops while in neutral in situation like waiting for a signal or at gas stations etc. It has a new battery, the fuel pump has already been changed at 55000 kms. The ATF and Oil changed at 80,000.