My waja has been sitting for 2-3 years during mco and after coming back msia the car started right up and ran perfectly and took it for all the basic maintenance like engine oil, mtf, brake oil and timming belt. But it has a check engine light that i dont remember having before and after confronting a few mechanics they could not figure out the problem and said it was nothing much. I also tried using my own obd2 reader to clear the code but still no use. Thw code is P0703 which says what brake light not illuminated but i check all my brake lights are working and so are my fog lights. I tried unpluging the battery letting it sit overnight but still no use. I replaced the brake switch for the 3rd time with an proton oem and adjusted the switch still no use. I even checked the continuity between pins to check whether it made contact when pedal is pressed and everything checked out. It did however went away one day suddenly but came back after pluging my obd to check something. It did however went away again and this time i did not plug the obd reader in nor touch anything related to the electricals but still came back after a few days. so can some proton experts help me. My waja is campro s4ph non cps.

ignore the fuel related code as i have replaced the faulty half cut fuel injector and crank sig fault cos my starter is going out. Because when start the car will have tick tick tick and eventually spin the engine so i think ecu think engine spinning but sensor no sense thats way ecu think cam sig got problem.

Some OBD reader cannot pakai 1, especially those cheap 1. You need go to proper mechanic shop to get real diagnostic machine to check on the fault codes. My mechanic tested few OBD reader, usually those cheap 1 really can cause mechanic a lot of trouble with fake error codes.

my obd reader isnt really cheap unlike the elm327 i tried before but did not even read codes. i bought mine for around 150 during discount. I even had mechanic to try theirs which they said cost around 1000+ and of a different brand.

150? Better you go to a proper mechanic and get their advice and proper diagnose.

thinkcar is a sub brand from launch (taikor)
just unsure of compatibility with msia made ecu

should be no issue, you might need to check the fusebox or any wiring leaks

Change the 3rd brake light bulb.
The resistance value is out of spec.