Major Problem????

troyertrain · 01-19-2006, 07:17 PM

I have quite the problem i think. i had a dead battery so i replaced it, no biggie. well when i was taking the old one out i took the ECU (thing attached to the air filter hose) out to move the hose around a little bit. well i forgot to plug it back in and i drove about 3 miles on it before i realized something was wrong. the transmission now shifts incredibly hard and the SERVICE ENGINE SOON light came on. i stopped driving it immeadiately and now it sits till i figure out whats wrong. any ideas??? any help is very much appreciated. thanks a lot everyone....

Vtolds · 01-19-2006, 07:31 PM

You should be fine, just plug it back in. The sensor was probably just telling your car that there so much air coming into it that it stiffened the shifts and turned the check engine light on.

AftermathAlero · 01-19-2006, 10:02 PM

yea.. restart it and plug it back in. within a few starts .. it'll be back to normal.

2fst4u · 01-19-2006, 11:37 PM

if you're worried about it, just disconnect the battery, touch the terminals together for 30 seconds, wait 15 minutes, then put it all back together. no problem, just need to reset the computer. and it's not the ecu you removed, it's the IAT. the ecu is the thing you need to reset. it's all good, tho.

AftermathAlero · 01-20-2006, 12:28 AM

Quote:

Originally posted by 2fst4u@Jan 19 2006, 10:37 PM
if you're worried about it, just disconnect the battery, touch the terminals together for 30 seconds, wait 15 minutes, then put it all back together. no problem, just need to reset the computer. and it's not the ecu you removed, it's the IAT. the ecu is the thing you need to reset. it's all good, tho.

Quoted post

Touch the terminal together? WTF never heard of that

-Alero- · 01-20-2006, 12:44 AM

Quote:

Originally posted by 2fst4u@Jan 20 2006, 12:37 AM
if you're worried about it, just disconnect the battery, touch the terminals together for 30 seconds, wait 15 minutes, then put it all back together. no problem, just need to reset the computer. and it's not the ecu you removed, it's the IAT. the ecu is the thing you need to reset. it's all good, tho.

Quoted post

ok....whatever you just said.......could quite possibly result in disrespect for the rest of your life....

IAT = Intake air temperature. which is a sensor that measures the air temperature in your intake system. which is most helpfull when your engine is at operating temp and at cold starts.

second, the problem causign the hard shifts would come from the MAF sensor (mass air flow sensor) disconnecting this harness or any damage to this harness will result in extreme hesitation and hard shifitng.

Take it from me and Aftermath it happened to both of us.

anyways to fix your problem simply plug this sensor back in and when you get the chance reset your PCM by disconnecting the negetive terminal for a minimum of 1 hour.

AftermathAlero · 01-20-2006, 12:46 AM

^^^^ agreed!

2fst4u · 01-20-2006, 01:08 AM

well, the above process was the advice given to me on this board when i first installed my intake a year and a half ago. the touching of the terminals clears any power from the car, and allows the computer to reset. it discharges all capacitors, simple electronics stuff. trust me, i'm in college for it, bud. and for the 2.4, the sensor that plugs into the intake is is called the iat, when unplugged, it changes the fuel curve and transmission line pressure. i do know a little bit of what i'm talking about.

-Alero- · 01-20-2006, 01:17 AM

Quote:

Originally posted by 2fst4u@Jan 20 2006, 02:08 AM
well, the above process was the advice given to me on this board when i first installed my intake a year and a half ago. the touching of the terminals clears any power from the car, and allows the computer to reset. it discharges all capacitors, simple electronics stuff. trust me, i'm in college for it, bud. and for the 2.4, the sensor that plugs into the intake is is called the iat, when unplugged, it changes the fuel curve and transmission line pressure. i do know a little bit of what i'm talking about.

Quoted post

so yo umean to tell me the temperature in the air results in different transmission line pressures?

AftermathAlero · 01-20-2006, 01:19 AM

Quote:

Originally posted by 2fst4u@Jan 20 2006, 12:08 AM
well, the above process was the advice given to me on this board when i first installed my intake a year and a half ago. the touching of the terminals clears any power from the car, and allows the computer to reset. it discharges all capacitors, simple electronics stuff. trust me, i'm in college for it, bud. and for the 2.4, the sensor that plugs into the intake is is called the iat, when unplugged, it changes the fuel curve and transmission line pressure. i do know a little bit of what i'm talking about.

Quoted post

No the IAT only give temperature readings to increase/decrease fuel injected. the MAF is what tells the computer the air reading for tranny pressure and good stuff. But this is the 3.4L engine

you have a 2.4L and 2.4 don't have a MAF unit. So I understand ur mistake .. the question is which engine does he have!

oh trust me, I've done electrical engineering and auto mechanic school. Its better to discharge the caps and poop, by itself. Than putting the 2 terminals together. Theres no need for that really. Its not going to make it any quicker or slower.

2fst4u · 01-20-2006, 01:24 AM

on the 2.4, the iat does change the stiffness of the shifts! i promise. i didn't have the stupid thing installed right in the beginning, and it would slam into gear. i know you don't have this engine, and i'm not sure what he has. i'm just giving my experiences. and as far as resetting the computer, no discharge isn't a necessity, but it makes me feel better to think i'm making it go faster, lol. i know that you're supposed to wait 15 minutes, tho, with your battery unhooked to reset the computer.

Fast Eddie · 01-20-2006, 10:21 AM

Quote:

Originally posted by 2fst4u@Jan 19 2006, 10:37 PM
if you're worried about it, just disconnect the battery, touch the terminals together for 30 seconds, wait 15 minutes, then put it all back together. no problem, just need to reset the computer. and it's not the ecu you removed, it's the IAT. the ecu is the thing you need to reset. it's all good, tho.

Quoted post

DUDE if you touch the terminals together you will short the battery, and back to where he started. DOn't do it. Just unhook it for 30+ minutes.

The IAT in combination with the MAP tells the PCM what to do with the tranny, and its line pressure, on the 2.4

natedawg9640 · 01-20-2006, 11:04 AM

i dont think he meant touch the battery terminals together... seeing how they are kinda immoble that would be hard to do anyway... i think he meant touch the positive and negative cables together... so complete the cars circuits without involving the battery... hence draining all resistors and stuff...

troyertrain · 01-20-2006, 11:19 AM

aight, all taken care of. thanks for all your help everyone.

brsexton · 01-22-2006, 05:08 PM

Quote:

Originally posted by 2fst4u@Jan 20 2006, 01:24 AM
on the 2.4, the iat does change the stiffness of the shifts! i promise. i didn't have the stupid thing installed right in the beginning, and it would slam into gear. i know you don't have this engine, and i'm not sure what he has. i'm just giving my experiences. and as far as resetting the computer, no discharge isn't a necessity, but it makes me feel better to think i'm making it go faster, lol. i know that you're supposed to wait 15 minutes, tho, with your battery unhooked to reset the computer.

Quoted post

Yes I will agree with you on this. I have the Ecotec and like the 2.4, it does not have a MAF sensor either. However it does have an IAT sensor. I left mine unpluged before and it caused the trans to SLAM into gear. So yeah, it does have an effect on the trans.