This is new member MissFitt and im glad to be here. I live in Washington state widowed, and although i understand in theory, most car functions and processes, i am old, they say lol, and my knowledge goes south for the most part after the time of the carburetor, depending on what systems with a car we are talking about. SO, now that theres sensors for everything under the sun, im flying blind.i worked in the auto industry for a few years, parts counter, service writer, ect., This seems like rocket science to me.
So heres my issue at present.
My car has several problems going on and every one of them are the same symptoms of both a bad ECM and a bad crankshaft position sensor. When i got the car, you could turn the key to start it and it would click. After a few tries, it always started. Then the key tumbler was sticking and i sometimes couldnt turn the key so i replaced that. When i bought it, they said the engine light was on due to a bad O2 SENSOR. Then i started getting a drain on the battery. A definite short so i got a new one. Not long after, it started running hot, not boiling over but hotter than it should but the temperature gauge never went past halfway. Then the new battery started going dead but I had the alternator checked and it was okay. Then the last few times i drove it, it ran rough, would die just driving down the road and guzzled gas. There was a power loss. Im by myself on a fixed income so i couldnt put it in the shop so i read the codes and it came up:
P0110 Air temperature circuit failure, Intake Air temperature sensor 1- bank 1, Inlet Air Temperature circuit

P0100 Flow meter electric Anomaly, Mass or Volume Air Flow circuit

P1400 EGR system, solenoid valve circuit

P0105 Absolute Pressure sensor/ circuit, MAP barometric pressure sensor circuit, Absolute Pressure sensor/ circuit, Inlet manifold pressure sensor circuit

P0731 Gear 1- ncorrect ratio,A/T 1st gear function

I cleared the cides and then drove it and parked it. A few days later i went out to check the codes again and, after charging the battery again, it wouldnt start. ahhhhhh, the P0105 & the P0731 codes werent there but the rest were, P0100,P0110 & P1400 and the code for the crankshaft position sensor. Its left me puzzled to say the least.
My questions are:
Should i replace both the ECM or whatever nissan calls it with the crankshaft sensor and where is that located? They all have the same engine so when i went to order the crankshaft position sensor theres one on the side, one on the front and one somewhere else?! Im unsure which one to order. Theres also the other codes/issues and a short somewhere and i probably need a new battery.
1.) What should i do first?
2.) Could a bad Ecm cause all those sensors to fail? I dont want to replace it but st this point its probably needed.
I3.) I read that getting another ECM, your key has to be reprogrammed??? Is that true even if i just have a regular key?
Jesus, see im clueless but i have to do this.
Can anyone advise me? I would so appreciate it. Any direction at all would be a blessing. Keep in mind i have to be the one doing it. So as simple as possible . Lmao! Yes guys, you got a live one here, lol