Nissan Repair Questions? Ask a Mechanic for Answers ASAP
Hello my name is ***** ***** thank you for your question.
When you turn the key to the ON position, are the engine cooling fans coming on?
The reason I asked about the fans, is if there is a Ecm failure, the engine fans normally come on when the ignition is turned on.
Do you have a test light or volt meter?
The Service Engine Soon light should come on when the ignition is turned on, that is part of Bulb Check.
ok. When you turn the key to the ON position, there is a security light on the top of the dash. Is that light out or ON solid when the key is turned on?
Well if your scanner can't communicate with the cars computer, the first thing I always do is go through all the fuses.
Oh! That security light is ON Solid when the key is turned on?
Off means it can read the key. ON solid means it can't read the chip in the key.
The OBD2 port should have 3 power sources. Do you have a Test light and Volt Meter?
Do not check security light with the engine turning over. Key in the ON position only
Did you check the fuses with a test light?
These IPDMs don't have Ecm relay issues like the Pathfinders or Xterra's.
Does the scanner you have work on another car? It is interesting that it won't communicate.
Let me know.
That is not good. Did you check to see how many power sources you have at the OBD2 connector?
You may have a 16 pin OBD2 port, but it doesn't have 16 pins in it. I just quickly hook up a volt meter and ground the negative lead and with the positive lead just quickly go through the pins. You should have 3 power sources.
Ok, So you do have 3 power sources.. That is good.
We may need to do a ECM terminal layout check to see why there is no communication. The fact there is no communication can be the reason it's not starting.
Hang on while I get that for you.
This is a 2.5 correct?
is this a 2.5 Altima?
That is the Ecm terminal layout. The way I do these checks is I print it and take it to the car. I do all the Key ON and Key off or Engine Turning over checks. I will take a pen and write down my readings as I take them so when I am done I can review them and see where it looks incorrect .
Yes, it will take maybe 1/2 hour or so. Sure, take your time. I will be online till late tonight.
I check them all. Cause if you find more than one that is out of spec, you can reference to see if they have something in common.
Let me know what you find when you are done.
Ecm is located behind the glove box.