We have recently purchased a used 2002 RAM 1500 2WD. Initially it would idle at a stop rough. I cleaned out the intake and that has stopped. Then all of a sudden when hitting a bump the warning lights including airbag abs etc in the center of the dash come on and it beeps. At the same time the speedometor and AC/Heater stop working. Hit a bump again and the lights go off and everything starts working again. Also it shifts hard all the time. Fluid is full but we do have a leak. We now have check engine light on with codes P0500 and P0121. I have been searching to figure out what to do to fix this. My husband thinks the computer is going out, yet has no idea why. My searches have come up with Control Module, Throttle Position Sensor, what do you suggest to try first. I called and all recalled wiring has been replaced on this truck. Help. We have 4 kids, both have 2 jobs, and no time or money to deal with a shop. I need to fix this myself but don't know where to start.