Every now and then the commander reports air temps as a negative number. The idle goes to hell. Then within a few minutes the values return to normal and the the idle goes stable. Now, I immediately suspected a loose connection at the air temp sensor under the UIM but it appears to be plugged in solidly. So here's the question...Does this indicate a failing air temp sensor? If not, any other ideas?

Marc Klinger

 

i would imagine it's most likely the sensor. i'm pretty sure i have a spare laying around if that's what you diagnose as the problem

 

I had the same problem in my FC...but from the time I replaced the air temp sensor with an FD one everything is ok...

 

Possibly a grounding issue, but that would cause other things to act whacky. I'd say bad sensor.

 

I've been dealling with this same issue for a while. I will be installing a new AIS tonight. I'll report back and let you know if it's the sensor or not. BTW, $46.00 FedEx'd from Ray @ Malloy Mazda.

 

I'll be looking forward to hearing your results. Thanks

 

Ok, I just changed my AIS last night. So far so good... I drove my car a half hour to work this morning and haven't seen a negative temp number yet. If I start seeing the negative numbers again, I will report back on this thread.

On a side note, getting at the AIS is a pain in the butt!! You have to remove the UIM/TB/Elbow and a whole bunch of **** connected to the UIM. You might be able to use a stubby 19mm box wrench, but I didn't have one.

 

Idle air controler $380 from mazda

 

It's been a few days and my Air temps have been staying in positive. I also initialized all data on my PFC and let it re-learn my idle. The car warms up and idles nice and smooth, albeit rich (AFR: 12.6+).

On a side note:My car also runs nice and lean 14.x-15.x at cruise with the O2 sensor feedback turned on again.

 

Just noticed my temp go in the negs this morning. I'll have to see if it is my sensor and replace it. Ever thought of moving the sensor to the Greddy elbow?

 

I have thought about relocating the sensor. But when i was swapping out my new sensor I tested it and saw just how slow the sensor's reaction time is. I figure that I will go throught the effort to reloacte the sensor when I figure out if there is a faster acting sensor out there. I have heard that there is a GM sensor that work for us...

 

when you use the gm sensor you have to redo all your air temp vs. (xxx) settings. thats what ive read on this forum anyways.

i was wondering. . . has anybody noticed a REAL difference when relocating the stock sensor?

paul