1.86GHz or 2.13GHz Processor, 128GB or 256GB Flash Storage

152 Questions View all

Sensor Temperature not Working?

Seems my sensor temperature is not working.

Can I repair it?

When I turn on my MacBook Air the fan is running all the time. I made Apple recommended procedures for reset SMC and PRAM and no success.

I opened the case and the fan is running all time, since I turn it on. Checking the RPM for the fan in a software it appears as 0 RPM.

Thanks for any help.


Screenshot. Fan appear 0 RPM, but it's running all the time at full speed (noise sound)

Block Image


Ok. I'm back after the tests!

1) Run the EFI test for the first time. FAILED the test:

Fan - Exaust (test 1) - Quick Motor Test

ERROR - Motor is spinning slower than it should.


2) Run the same EFI test again and than DON'T FAILED. It PASSED!

3) Run the OS test. Everything PASSED!

During all tests the FAN is running in a noise mode.

You can check the screenshots in that link:


Block Image

Block Image

Block Image

Any Help???


Answered! View the answer I have this problem too

Is this a good question?

Score 0


Made a Apple Hardware Test and got the error: 4MOT / 4 / 40000002: Exaust -0

But as I said, the fan is running.


Replace the fan.


Add a comment

2 Answers

Chosen Solution

I suspect the sensor within the motor is not working or the ribbon cable has a nick in it or the connector on the logic board is not fully seated so the feedback circuit is not working.

Lets try this, download this app: Temperature Gauge Pro. Paste a screenshot on what is shows so we can see.

Was this answer helpful?

Score 4


Update with the screenshot.


You'll need a new fan unit and be careful here! As the fan connector on the logic board can be broken if you are too rough.


Add a comment

That says nothing.

Run ASD and tell me what sensor is failing, without this we are just guessing. If you are correct and this is indeed a 2010 model, you need 3S142. Come back and bear useful information, and I will tell you what to do to fix it.

To clarify: your homework, step by step, is to

1) find out what ASD is

2) find out where to download it

3) find out how to install it on a bootable USB and/or external hard drive

4) find out how to run it to tell me which sensor is failing

Was this answer helpful?

Score 2


ok Sensei, I'm glad you clarified that...


Louis why are you sending him on a snipe hunt here? Apple is very aggressive in hunting down sites offering ASD these days and having it pulled. The few that do are bogus or are infected with malware or other nasties!


Hey Louis... Step 2 is almost impossible... trying to find it yet.



Got it. Will made the tests


I'm not psychic. I can't tell if it's TS0P, TH1H, etc sensor from 3000 miles away without testing. ASD can. Without tools you have virtually no chance of solving this unless it's some easy problem like DC in board or trackpad. I'm not surprised Apple limits distribution of the tool, dare people be able to fix what they have..


Show 3 more comments

Add a comment

Add your answer

Leonardo will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 4

Past 30 Days: 20

All Time: 816