Jeep Grand Cherokee 2.7CRD laredo 2004 (WJ) in LIMP mode HELP?

Hi , my jeep wj is in limp mode and I receive 3 errors : P0700 , P0703 and P0340

P0700 has to do with either the solenoids or the TCM

P0703 is a brake switch stuck

P0340 is something to do with camshaft position sensor

None of these makes any sense considering that the battery was flat when the car first went in to LIMP mode , after replacing battery I received these errors. I did get experts to clear and reset my cars computer and these 3 errors remain. I did not drive when these errors accord nor did i do anything that can possibly create these errors . I get stupid answers from mechanics that is suppose to be experts that tell me I should replace the ECU in my car , which is not cheap nor making any sense to me.I live in South Africa and in a rural area , with mechanics in the city only seeming to want more and more money for replacing parts that is not at fault. IF ANYBODY CAN EITHER HELP OR GIVE ME ADVICE IT WILL BE GREATLY APPRECIATED. I am begging you please help me

Thanks in advance for anybody who responded to my plea for help