okay i bought a brand new knock sensor about a month ago from courtesy nissan and my check engine light was still on b/c of the IAT sensor and the front O2 sensor, well ipulled the code just the other day and the only codes i am getting now are the Automatic transmission signal to ecu or something which may be caused by a defective battery, the O2 sensor, and a KNOCK SENSOR, why is this, my part came straight from japan so i know it has to be good lol, oh and also my e-brake light is on, i think that may have to do with my battery also b/c when my alt belt broke it did that, i put a new one on and it was fine, what is the deal, can anyone help

 

maybe your alternator is gone . That's the only reason why all of them would come on at the same time.

Turn on your car, unplug the red connector to the battery and check and see if the car stays on. if it does than the alt is fine.

 

alt is good, but i thought it was the negative you took off, see when i go to start the car it cranks real slow then the alt i guess charges the batt. and it starts cuz it starts spining faster,but i bought a new batt. just now so ill see if it works for that but what about the knock sensor code???

 

ok got a new batt and it starts perfectly runs perfectly and shifts better, i started my car and the cel was off but the e-brake light was still on...wierd lol but this morning my cel light came back on, can someone please tell me why my e-brake light is on has this happened to anyone else????