GM Test IDs And What They Mean (long read)

[Brando56894]

(skip this paragraph if you want to its just background info) awhile ago my dad bought one of those nice scanners that mechanics use (a MacTools ET9620) off of eBay for around $200-$400 and it was practically brand new. my mom being the cleaning addict she is buried it somewhere, a few weeks ago he found it and i used it to scan a code my car was throwing (turned out to be P0113 IAT Circuit High Input). we read in the haines manual that the pcm throws that code when the air is too cold, i imeadiately knew it was cuz of my CAI but the wierd thing is that it threw it the night i was heading up to the trucks (with the ttops off) and it was pouring. after everyone decided to leave me and pat took the tops off and it drizzled on and off, after awhile we pulled over on the turnpike, put the tops on and at that exact moment it threw the code. [now back to my original point, yea i know im a story teller]

Ive been messing around with it cuz im a gadget freak and ran the "Non-Continous Tests" and got a bunch of information that i have no idea what to do with. I made a spread sheet of test $10 and found out in the (extremely outdated) manual that the values are in hex so i decoded them but still have no idea what the hell im doing

Supposedly GM (and all other manufacturers) have codes for these specific things, but ive searched the interweb to try and figure out what all these things mean, but im stuck

these are the non-continous tests that are available for my car: $05 $06 $07 $0A and $0C. $05 gives me the most info so thats the one that i made the spread sheet of but have no idea what all the numbers mean, all i know is that most of the Stats are "ok" and a few are "low" (a few of the measurements are 0 prolly because i just reset the pcm)

conclusion: wtf do all these values mean???? what specifically is "low" and how can i make it "ok"??

Scan Spreadsheet (sorry its on rapidshare, the board doesnt allow .xls extenstions) for some stupid reason it calculates one specific cell and none of the others so C11 is supposed to read 3E60 in Hex

[Savage_Messiah]

uhhh how about this, maybe your IAT sensor is messed up??

I highly highly highly highly highly doubt the air your car was drawing in was "too cold."

[GP99GT]

Originally Posted by Savage_Messiah

uhhh how about this, maybe your IAT sensor is messed up??

I highly highly highly highly highly doubt the air your car was drawing in was "too cold."

x2, pop it out and clean it, if it throws the code agian, buy a new one, or check the wiring. if it shorts it would read full voltage

[Brando56894]

i doubt that my IAT is messed up (but come to think of it, the scanner does say IAT is -38* ), i disconnected the battery to reset the PCM and the code didnt pop up, so i drove it around some more and it didnt throw anything. a few mins later i got the scanner set it to record frames and was driving "normal" then WOT a few times to see if it would throw anything. nothing. we'll see tomorrow (today?) if it throws anything since i have to go to court up in wayne for when i got caught speeding down hamburg turnpike @ like 8am so i could make it to bill's/mufflex ontime.

I'll be in wayne from 3pm tuesday till prolly 9pm wednesday (im chillen at a friends apt for the day/night so i dont have to drive the 2.5+ hours home in one day and ill only be 45 mins from the trucks) so if my friend cory has sumthin to do during the day on wednesday i guess ill hit one of you northern guys up and see whats goin on.

now back on topic, i meant wtf do all those values mean (in the spreadsheet) not what does the code mean (or what caused it, i could prolly figure that one out myself). i'm curious to know whats "low" and whats "ok" im gonna run the same test when i get home on thursday (since i'll have put 300+ miles on my car by then and all the "flags" should be set)

[Savage_Messiah]

sensor reading of -38 means the sensor is f'd up. If it pops up again bring your piece to my house and we can try a different sensor in it

[89 Trans Am WS6]

Car feel like it had more go?

Gas gauge go just as quick? I can imagine the fueling that must be going on with a IAT of -38 degrees hah

[IROCdan330]

brandon...all those values that youre seeing is all your type of language...i believe that they are how the pcm is interpretting what the vehicles sensors are telling it...the big time tuner guys would be able to give you a better idea.

your CAI isnt throwing that code...chances are the sensor is f-ed. its a thermistor and its going to be relatively easy to change, and shouldnt be too expensive. -38 means that the sensor is f-ed up as has already been stated...i'm not sure if GM uses PTC thermistors (temp up, resistance up) or NTC thermistors (temp up, resistance down)...but regardless, there is either too much resistance there or not quite enough. Make a movie with this scan tool of yours, then review it. Look at not only the IAT pid in degrees, but look at IAT voltage as well. I'm willing to bet its either 0 or close to 5 volts, meaning that a. youve got a short to power, an open, or the thermistor is just shot...it does happen.

[Savage_Messiah]

the dumb$#%^ had the IAT unplugged and didn't realize it, AFAIK problem is gone

[Brando56894]

somehow the damn thing came unplugged, i noticed it when i was up in wayne last week and pulled into a school cuz sum dude had a 79 TA for sale, then i noticed a noise and popped the hood. sure enough there it was, the IAT hitting the serpentine belt problems gone now

on another note how long does it take for the EVAP "flag" to set? i have to get my car inspected and everythings set except that and ive driven about 400+ miles and afaik its not set. ill check it later