I had a really weird thing happen to the car last night at the track that I can't seem to figure out.

It's about a 75 mile drive and all the way there the car was fine. After paying to get in and then driving over to the tech inspection lanes I noticed the car wouldn't shift out of first gear. At first I thought I might have left it in S mode but just before I stopped the car I saw that it was actually in D.

About 20 mins later everybody in my lane started getting ready for our first time trial. I was about 10 cars back so I fire up the car and start moving forward. When I get to about 2 cars from the front, the check engine light comes on and then the car barely wants to move forward anymore. Even though the car's an automatic it felt like the car had a clutch that was slipping really badly.

Instead of trying to run I hobbled back to my place in line and then pulled out my scanner to read the code. It ended up being a P0700 (Transmission Control System Malfunction) but oddly enough I cleared the code and tried a little test launch and the car seemed fine so I turned it off and waited for my second run.

Just as I was then getting ready for my burnout the check engine light came on again but since the car felt fine I kept going. The car did a great burnout and I launched fine but about halfway down the track the car went into some sort of limp mode and I was barely able to make it back around.

As it turns out, we ended up getting rained out but I was worried about getting home so I cleared the code and hoped for the best.

Now here's the really weird part - not only was I able to make it home okay, I drove the car as hard as I could (including getting it up to 130 on the freeway) and the car didn't hiccup even once.

So does anybody have ANY ideas (even far-fetched ones) as to what it might be? Although I did just finish several mods to the car (including a differential and converter) it ran amazingly well at the track the week before.

Thanks for reading,
Christopher

 

I don't know if this is related or not, but I'm wondering if the line lock that I installed the night before is somehow connected?

I just talked to Eli at Red Star Performance (the guy who sold me the converter) and when he mentioned something about my burnout, that got me wondering if that was more than just a coincidence.

 

Not sure if this will help, but on a Chrysler 300M I had 6 years ago, my car intermittently went into a limp-home mode and wouldn't switch out of 2nd gear. After it happened a couple of times I took it to the dealer and they said an "input sensor" in the transmission had failed, so the engine computer got confused and put the car in limp home mode. It was a simple warranty fix.

Different car, but similar symptoms...

 

Thanks, that does help as Eli suggested
something very similar. In addition to the main transmission connector there are 2 or 3 sensors which could be causing the problem .

Oh, how I'd love to still be able to have it checked under warranty...

 

how low was the air pressure

 

I had the same thing happen to me 2 days ago....I'm taking it to the dealer in two days...My guess was a sensor, too. Sence it never happend again. However tonight i couldn't start the car for about 2min..After that everything was fine...

So, now i think it could be a problem with the computer...Mine is also a 2005 auto.

 

PLEASE keep me posted with the details of what the dealership does to fix the car. You can either post it here or send me a PM.

Air pressure? In my drag radials? It was 25PSI but I'm not sure how that could be related.

 

i would keep my tires at 25lbs hot. depending on out side temps while waiting to run. the tire pressure would drop to 23 even if just1 tire. normal driving it would be fine. hard excelaration i would get a code trans would be in limp mode. i cleared it would drive fine. next time it did it i left the code reader in, and instead of clearing, i added air and it cleared itself

 

My psi was 30 on all tires. Also, they were the stock tires from gm...I'm almost 100% sure it has something to do with the computer becasue when it happend to me all i had to do is turn the car off and then on after 2 minutes...It took me two times to get the transmission normal again.....

By the way in my case when it happend when i took my foot of the brakes and had the car on drive, the car didn't move. I had to have my foot 1/5 or so on the gas paddle for the car to start moving. Idon't know if the same thing happend to you thesubfloor?

 

yes it was like it was slipping and wouldnt shift. it went to 2nd but slid in you couldnt feel the shift

 

Yep, that's how mine behaved, like the transmission was slipping and it didn't want to shift.