getting hot again, pcm problem?cooling fans not working

hi greetings from los angeles ca.my 2001 alero 3400 engine is getting hot again this alero is running with a 2001 impala engine run great for few months, replace radiator, hoses, thermostat and suddenly coolant start leaking in the overflow, fans not working even with ac on, i replace the etc sensor and did not work, the fans turn on when i disconect the etc sensor so i think the fan motors are ok,so please if anyone with info regarding this problem will be greatly appreciated i got one pcm module from the salvage yard in case i need to replace it but i read that only the dealer can reprogram the computer system because vin number issues please any help is welcome thanks in advance

has the vehicle been scanned for codes?

Is it only overheating in traffic, but is ok on the highway?

hi again i took my alero to an electrical shop because the cooling fans did not turn on and the shop fix the problem i was charged $150.00 the car is running great, the man did not tell me what was the specific problem but since the car is not overheating ... problem solved thanks anyway for the help