Inlet Air Sensor

[Johnboy]

I have a question regarding the air inlet temp. sensor. I have noticed that the reading seems to run from 140-195deg.F. This seems awful high to me and was wondering how much of an offset on the MAF it is giving me? The reason I'm concerned about it is that I recently failed my emissions test for high CO(rich) and was wondering if this had something to do with it. My BLM readings seem ok 114-125. I am running the stock MAF and sensor is located in the K&N filter.

Thanx

 

[strikeeagle]

Perhaps more important, if your MATs are truly that high, you might want to consider a good cold air kit like Pete Tomka's, because your car's performance can't be the best...

strike

 

[Johnboy]

I took the sensor out and let it stabilize at room temp. Re-installed in the car and checked again and the reading was 151 Deg. F. It's either the sensor is n/g or the aldl software I'm using to get the number is not working right.

 

[BlackBandit]

You can check the sensor with an ohm meter. Just let it set in a 70 degree room and then measure the resistance. If it's in the 3.5k ohm range it's probably working correctly. Another way is to take the sensor out of the filter but leave it connected to the harness and let it set (out of sunlight or any other heat source) and then see if it measures the room temp via however you're getting your measurement.

 

[TurboDave]

I took the sensor out and let it stabilize at room temp. Re-installed in the car and checked again and the reading was 151 Deg. F. It's either the sensor is n/g or the aldl software I'm using to get the number is not working right.

How are you obtaining your reading?

 

[Johnboy]

You can check the sensor with an ohm meter. Just let it set in a 70 degree room and then measure the resistance. If it's in the 3.5k ohm range it's probably working correctly. Another way is to take the sensor out of the filter but leave it connected to the harness and let it set (out of sunlight or any other heat source) and then see if it measures the room temp via however you're getting your measurement.

With mine at room temp. it reads about 2.5K ohm, but reads 150deg.f on ALDL scantool. If the resistance is lower than expected shouldn't this make it read lower not higher?

 

[Johnboy]

How are you obtaining your reading?

It's the free software Win ALDL

All other readings look ok except for this one???

 

[BlackBandit]

At the resistance goes down the ecm reads a higher temperature.

F C ohms

210 100 185
160 70 450
100 38 1,800
70 20 3,400
40 4 7,500
20 -7 13,500
0 -18 25,000
-40 -40 100,000+

Edit:first column is degrees f, second is degrees C, third is appropriate resistance.


That's the table according to gntype. If your sensor reads 2.5k at 70 degrees then it's kaput. What's probably happening is the resistance is dropping too far and so the ecm see's 150 degrees when it's only 80-90. (or something like that) This is assuming it really was 70 when you measured it. You could stick a 3.4k resistor in the MAT plug to see if your software is working right. HTH. james

 

[Johnboy]

Well I found a 3.2K ohm resistor to test it and it read 120 deg.f, when it should have read around 68 deg.f or so. It looks like it might be the software or the ECM??. This all the more reason for me to buy a scanmaster now. As far as the sensor using the reading provided above it doesn't appear to be that far off, 2.5K appears to be close to 85 Deg. F. It was actually around 77 deg. F in my house when I tested the sensor.