Sometimes my trac light comes on and the car shifts hard. Any ideas?
the shifting hard is usually an unplugged or bad iat sensor. as for the trac light issue im having the same thing happen to me so if you find the source post it up.
Where is this sensor located at cause I am having the same problem.
Ok, sometimes ill be driving and the car will be fine, then the trac light comes on, usually it happens after ive stopped and i hit the gas again.. The trac off light comes on, then the car wont shift until the engine gets up to about 4000-5000 rpm.. Then it shifts hard.. It seems like it might be a tranny problem?? Once i shut the car off and start it back up the trac light stays off, and the problem goes away... The car has gained about 35,000 miles since i got it in november... And is now up to 153k... Could really use some advice guys... This car seems to be on the slow boat to hades if you know what i mean... Its fallin apart fast.
Btw, my engine light has been on since i got the car, that code 440 or 1440 or whatever... There was a service bulletin about the problem, just havent fixed it yet... So i have no way of knowing if the car is throwing a code.
Ok I fixed mine. I replaced the iat and disconnected the battery to reset the computer. Started back up no lights on and shifts just fine. Thank god I wa really dreading a tranny service bill.
Big J wrote:Ok I fixed mine. I replaced the iat and disconnected the battery to reset the computer. Started back up no lights on and shifts just fine. Thank god I wa really dreading a tranny service bill.
the tranny shifting hard is actually it's was of protecting itself. the clutches not slipping and just engaging is how it does this.
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Joshua Pavao wrote:Btw, my engine light has been on since i got the car, that code 440 or 1440 or whatever... There was a service bulletin about the problem, just havent fixed it yet... So i have no way of knowing if the car is throwing a code.
AutoZone.
IAT sensor bad/unhooked causes hard shifting. I was about to ask if it started happening along with the install of an intake.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
its def an IAT sensor. Its a simple fix and with common tools you can easily do this yourself.
Not unintentionally accelerating since 2009!!!!
okay update.
so the car to this date still does this, not too often in town, unless the a/c is on.
anyway, a few days ago i got a code scanner for about 40$ on amazon.
plugged it in, (engine light was on, and has been since i got the car) and i got three codes. Code one was P0440 (no flow during purge cycle) and P0122 (Throt Pos sensor low value) and then P0440 again.
i've heard P0440 is usually a gas cap, or wiring prob with evap system.
So, yesterday i figured i'd give this thing the ultimate test. i had to take a trip out by freeport, and knew the trac light would come on and it would give me the hard shifting problem. So before i left the house, i got out to the car, erased all the codes on the computer of the sunfire and started the drive(leaving the scanner plugged in). I got about 60 miles before i turned the a/c on, about 10 miles later the Traction control light came on, and the car started shifting hard. As soon as the trac light came on, the scanner read a code P0122 as PENDING and the Check Engine light was not lit up yet. After a few complete stops (once i got to town about 15-20 miles later) the engine light came on and it read 2 codes, one MIL (check engine light on) and one Freeze Frame.. the new code was the P0440 code, and the second code was the P0122.
i have no idea why the a/c being on would make the car throw codes sooner... other than the additional load on the engine.
but it still puts those codes out even if the a/c is off it just takes longer.
also the problem occurs faster if i'm driving in town, as opposed to on the highway. (20-25 min of city driving as opposed to about 60-70 min of highway driving.)
WHEW.
so anyway, point is, today i guess i go look at my TPS sensor, along with the IAT sensor. oh, and get a new gas-cap.
it's not that big of a problem i suppose, just kind of annoying when it bangs into gears :S
hope this helps anyone with this prob. i'll keep you updated as i find out more.
i had this happen on my 97 cavy LN2 at about 108k miles i replaced the sensor twice and still had the same problem however i went to work the next day and grabbed my test light . turns out the pigtails to my iat sensor and the one to my ect sensor were bad went to the junkyard cut them from another cavy and problem was solved disconnect the batt for ab an hour and your computer should clear itself
MEAN & GREEN.
I unhooked the battery all night and when I hooked the battery back up the next day negative first and the problem went away. Try that.
