computer fried?

[rosco]

car will not go past 3500 rpm.
battery is good, 12.33 volts
not getting any signal on code reader at all good or bad.
no warning lights, no engine noises, runs just a little rough, exhaust feels like it is getting hotter faster than normal.
replaced air filters "optimist"

26k miles never raced.

already tried resetting computer by disconnecting battery for 20 minutes, no change.

not getting any signal at the code reader port is most troubling.

any way to check it myself?

 

[Tom Sessions]

What year car is it? Any Mods to the car?

 

[rosco]

2006. bone stock except for corsa exhaust.

 

[rw99]

It was perfectly fine the last time you drove it? How long ago was that?

IAT sensor properly connected/seated?

 

[rosco]

noticed decreased performance for the last week. have not pushed it for a few weeks and worked fine last time i did probably a month ago. but last sunday i pushed it and it would not go past 3500 rpm floored in first second or third. first thought was air filters. replaced them. seriously doubt it would be converters with only 26k miles.

most troubling is the complete lack of signal at the code reader port which says i atleast have some type of electrical problem even if it is not related to the poor performance.

every other aspect of the car works fine. alarm, lights, radio, even the engine works up to a point. my thinking is that the computer took a dump and the car is working on some default setting. or not.

what is IAT sensor? excuse my ignorance.

 

[VIPER R]

Can you try a different code reader, just to be sure. The temp. rise sounds like Cats.

 

[slysnake]

Isn't that limp mode rpm? Better get it to the shop.

 

[rosco]

reader works fine on my truck, checked it. temp rise does sound like cats but odds of loosing one at 26k miles is low. and have you seen them? its a hollow tube with a screen. its a cat in name only. would take some serious build up to block one.

odd smell to exhaust too. like water vapor or running too lean. bad gass would make it run poorly across the whole rpm range and misfire at idle. been there. its not doing that.

and none of that explains why not even getting any signal on the reader. not even the connected sign. really think the computer is MIA. any way to check? dont want to take it to the dealer, they will just start throwing parts at it untill it starts working 5k later.

 

[mjorgensen Woodhouse]

PCM is bad and the dealer will have to send in the old one for you to get a replacement. The factory has to flash the current mileage and VIN into the new one so no one tries to sell the car with less miles then it really has. The cats can and go bad, but they melt from over fueling contamination generally from a bad running car, not really plug. The no read condition will confirm this is the problem even though it does not have a CEL, probably because the PCM is bad.

 

[rosco]

did the bulb reading method. turned ingition on. light stayed lit for 14 seconds then flashed for 11 seconds. definatly something going on with PCM.

anyone have any luck with these people who claim to "repair" the pcm? not keen on blowing 800 bucks but will **** it up if i have to.

 

[bluesrt]

if your signal states no communication, u have what mark states- bad computer

 

[Dan Cragin]

Sounds like a plugged exhaust to me. Have a backpressure test done.

 

[bluesrt]

what does it state when you plug a code reader to the aldl? does your cig lighter work? or adapter?

 

[Jay M]

When my cats were plugged it had the exact same symptoms- no codes, no warning; smelled like it was running rich. Have it towed, don't drive it. With my 2004, there was an 8/80,000 emissions warranty. I barely made with only a few months to spare! It saved me thousands, With those thousands I saved, I decided to buy an extended warranty.

~Jay

 

[rosco]

PCM and data port working again. PCM is fused like an above poster said on the "cig ltr" fuse. and guess what? the cig lighter is not on that fuse. only thing on that fuse is the PCM and hydrolic cooling system. which might explain the heat. will road test it tomarrow night when its quiet and most of the po po have gone to bed......

still in warrentee for the converters so yea for that if it is the problem, but betting it was the PCM. also betting it is mislabeled intentionally so they can sell you a new one/ which may also be why you can find NO referance in the shop manuel or on the web concerning the existance of a PCM fuse or its location. shop manuel only shows the existence of the fuse in the wiring diagrams as the power wire as "fused"and lists it as slot "11" in the fuse box. the fuse box has no numbers. just pulled them all, found a blown one, replaced it and everything is working again.

 

[rw99]

the fuse box has no numbers. just pulled them all, found a blown one, replaced it and everything is working again.

Nice. I'm putting that troubleshooting in my memory bank...