Mechanics

TRANSMISSION PROBLEMS AFTER A LOW BATTERY. CHECK ENGINE LIGHT ON CODE P0720.

2006 Chrysler Sebring • 151,000 miles

Overnight we accidently left something plugged into the car, which in turn drained the battery to very low by morning when we needed it to drive to work, but it still started. Driving to work the battery warning light turned on but nothing more was wrong with anything. Only until 2 days later did the battery light turn off, after a few trips of recharging it. But shortly after it did turn off, maybe 2 minutes, while at a stop light the speedometer went up to 15mph and a little jump forward, while at a complete stop.

So the rest of night the car was driving that way, and even in park the speedometer jumps up to 15mph.

The next morning while driving around we found it difficult to get above 35 mph, without the rpm going over 4000. Now randomly it will have difficulty going over 35 mph with the rpm jumping to 4-5000. Other times it will shift right and we will be going 70 down the highway at a little over 2000. When we stop it jumps a little still and jumps up to 15 mph still.

The check engine light actually turned on that morning also, and the error code was P0720 (Low output speed sensor speed above 15 MPH). We cleared the code, but it turned on a mile later down the road and changed nothing to the way the car drives.

If you have any idea if the transmission has gone bad or if something small is going on, it would be greatly appreciated!
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Breentz
July 24, 2012.




Low voltage does crazy things to computers.

First, have the alt checked as the light was on. You should have 14 to 14.5 volts at the battery with the motor on.

If that is ok. Turn off the car, remove the negative battery cable for 15 seconds and re install. This will re boot adaptive learning. Start the car and let it idle for 5 minutes and take it for a ride and see what happens

Roy

ASEMaster6371
Jul 25, 2012.
For the first thing, what should I do to check the voltage of the battery (is there a place that would check for me).

Since we didn't know the answer to the first we skipped to the second part (hopefully wasn't a bad thing) but we disconnected the cable and reconnected it and idled the car. The first 10 minutes of driving were improved and the check engine light turned off, but after 50 miles it started again.

So if you think of any solution to the first part for me that would be awesome.

Tiny
Breentz
Jul 25, 2012.
You will need to have a trans shop to check it out to see if it is external or internal failure.

Roy

ASEMaster6371
Jul 25, 2012.
I have the same exact problem did you ever figure out what it was?
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Tiny
Bobsanchez
Nov 2, 2012.

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