# 2000 Nissan Maxima GLE A/C Problem



## dgkb (Jul 22, 2012)

So here is the deal NissanForums, I have taken my car to get the A/C system checked and after doing the basic diagnostics tests, the tests point to a faulty computer (engine control module is that the proper name?) located under the dashboard. 

Now, I am not completely sure what this computer does but as far as I am concerned, it sends signals to the compressor clutch.

The mechanic advised me to purchase a new computer and see if that makes the A/C work.

What do you all advise? 

Thanks for the help.


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## smj999smj (Jan 1, 2006)

The ECM is an engine management computer, however, on many late models, an ECM also can control the A/C relay. The A/C relay sends power to the A/C compressor clutch. So, it's possible that you have a bad ECM, but I didn't perform the diagnosis so the question is do you trust your mechanic? I get concerned when someone says to "try something and see if it works." If he was confident in his diagnosis, he would tell you that it needs an ECM, not try it. Will he guarantee his diagnosis and cover the cost of the ECM if it doesn't fix your problem? If you purchase a new ECM, you'll have to initialize the keys or the vehicle will not start. Also, the Idle Air Volume will need to be learned to the ECM after it's installed. Another option is to send your ECM out to a place that repairs ECMs; you can search for them online. They can test your ECM to see if it's bad and make the repairs at a fraction of the cost of a new ECM. Often they can do this and return it in a state so that the keys will not need to be initialized.


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## dgkb (Jul 22, 2012)

Thanks for the response smj999smj. This whole ordeal seems more complicated than I first thought. 

So, it would be cheaper and more convenient to have someone look at the stock ECM instead of purchasing a new one.

Does this hold true for a OEM ECM?


It also seems that the mechanic was being honest and did many tests to isolate the issue. I am hoping that he is correct and I will ask with what certainty he is working with before making any purchases.


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## smj999smj (Jan 1, 2006)

A remanufactured ECM from Nissan MSRPs @ $865 plus $100 core charge, which doesn't include what the dealer will charge for initializing the keys. Sending your computer out to have it repaired usually costs $200-$300.


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## dgkb (Jul 22, 2012)

Thank you again for your response, the prices do seem accurate after self exploration. 

I have since taken the car to be examined by another mechanic with a different point of view. He claims that the issue lies on the actual a/c control unit inside the vehicle. I.e, the reason that the compressor is not kicking in is because the buttons on the control unit are not working properly. 

Could this be true? Should this be replaced instead of the more expensive ECM?

As always any input is appreciated.


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## smj999smj (Jan 1, 2006)

It could be, but without having your car available to be able to diagnose it myself, I can't tell you what the problem is. I can only go by what you and our mechanics say.


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