MAT sensor

[DrBerko]

Posted this in the Eighty Eight section - but did not get any responses...trying again.

First post here, so thanks in advance for the replies. The service engine soon light came on in my 91 Eighty Eight. After pulling the diagnostic code, found that the MAT sensor was bad. I replaced the sensor and the service engine light was still on. I removed the negative battery terminal and replaced it after waiting for about 10 minutes, the light is still on. I checked the resistance on the old sesor, which was about 1330 Ohm, the resistance dropped rapidly when I heated the sensor with a hair dryer. Any susggestions as to what the problem may be, I'm not convinced that the sensor was bad after all.

[GMMerlin]

Originally Posted by DrBerko

Posted this in the Eighty Eight section - but did not get any responses...trying again.

First post here, so thanks in advance for the replies. The service engine soon light came on in my 91 Eighty Eight. After pulling the diagnostic code, found that the MAT sensor was bad. I replaced the sensor and the service engine light was still on. I removed the negative battery terminal and replaced it after waiting for about 10 minutes, the light is still on. I checked the resistance on the old sesor, which was about 1330 Ohm, the resistance dropped rapidly when I heated the sensor with a hair dryer. Any susggestions as to what the problem may be, I'm not convinced that the sensor was bad after all.

I'm assuming you are talking about theMmanifold Air Temperature sensor.
What may be going on is the sensor is fine, but there is an issue with the wiring.
Depending on the code #, it could be high or low...so you could have an open circuit to the ECM or a grounded circuit to the ECM