Transmission Problem? [Archive] - Forum


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10-14-2005, 07:24 PM
Here is the scoop, every couple of weeks or so my car will start shifting really hard while driving and when I put it into reverse, then the service engine light will come on for a day or two go off and the car will drive fine for a few weeks. I can tell when its about to happen because there will be a whining noise when I am going at low speeds, especially when I am just coasting. This has been going on for like 4 months and I know I should just take it in but I was just curious if anybody else has or had the same problem....thanks.

10-15-2005, 03:02 PM
You should really have your fluid level checked.

10-17-2005, 12:14 AM
Just to let you know, mine did the same thing. It is caused by shifting into another gear while the car is still if you are backing out of your driveway and then shift it into drive when it is still rolling backwards...BAD NEWS FOR YOUR TRANS. Basically i took it to the dealer after a huge headache with my local trans shop and it cost $130 bucks for them to replace something called an IAT Sensor Connector. What they told me is that new trans run off of air pressure which shifts the gears and this sensor is getting incorrect readings so it makes it shift wrong. I thought my trans was gonna fall off because it clunked so loud when i shifted. But that was my problem, good luck, and i hope it isnt a bad trans.

10-17-2005, 03:44 PM
Bwahahahahaha. Sorry bud, you got owned:

So many things wrong with that, so little time.

FYI: IAT stands for Intake Air Temperature sensor. The MAP senses air pressure (or rather engine manifold vacuum), not the IAT.

The trans uses hydraulic (oil) pressure to shift the gears, not pnuematic (air). The computer does use the MAP sensor to see how much load is on the motor to determine how to shift the car, but that has nothing to do with the IAT. They probably just reset your computer and charged your $130 to do it. :heh:

Shifting into drive while moving backwards or vice-versa is bad for your trans, but it wouldn't hurt anything electronic, and certainly, not your IAT connector.

10-17-2005, 03:56 PM
It is possible, however unlikely, that "some sensor" somewhere could possibly mess with your PCM enough to make you tranny shift incorrectly since it is electronic. Like DarkKnight said the tranny uses hydraulic pressure to do the work but most valves are shifted by solenoids that are controlled by the PCM in these newer cars.

Something lost in translation maybe?

10-22-2005, 07:41 AM
I believe he was trying to say that since his IAT sensor was bad, his idle was too high. When your idle is too high, the transmission will clunk when you put it into gear.