2003 Highlander - Transmission Problem?

[Dove]

Last Saturday, I didn't shut my door completely and my battery drained over the course of the afternoon. It wasn't completely dead, but didn't have enough juice to start. It was good to go again after a charge (we have a battery charger at the house), but it wouldn't start the next day so my hubby has been putting the car on trickle charge every night since. If I have any more problems I will go ahead and replace the battery even though it's only 2 yrs. old.

Today on the way home from work, I noticed that the car kind of "hesitates" when shifting. I jokingly suggested to my hubby that maybe it was related to the battery, but after reading another other post, I wonder if maybe this problem is electrical. We checked the transmission fluid and it was red/clean/at the proper level.

This is a '03 AWD Limited with 80K miles and has been dealer serviced every 5K miles. This is the first problem I've ever had with this car, and it's not settling well with me that there might be a BIG problem with it.

Thanks for any suggestions!

[bepperb]

It may very well be related to the ECU being reset by the dead battery. Give the car some time to relearn the shift points, it will likely go back to what you're used to over time.

But to the original issue, it sounds like something is draining the battery. Are you sure you left the door open the first night? It may be the battery is shot, but it could just as easily be something else is draining it every night. Most auto parts stores/shops can test your battery for you to see where the problem lies.

[LifeTech]

Deep cycling a battery ( lights or accessory power on) for many hours can sometimes short a cell within the battery and even sulfate the cell plates. The battery may have lost reserve voltage even though it has been trickle charged. I would check fluid level( if accessible add only distilled water if needed) as well as trickle charge every night for a few days. If NG after that your two year old battery may be done.
AutoZone will test your battery for free and even install one for free.

Some better higher end battery chargers have the ability to condition cycle the battery...takes about 24 hours. This breaks down the sulfates from the cell plates and back to the acid fluid.

I have a Black and Decker charger that cost $69 from Wally World.

It does everything from test batt. load to testing the alternater to jump starting and trickle. But this one also desulfates the battery.
Just some thoughts on your battery situation.

I agree with bepperb that the the dead battery may have caused the ECM to reset and the ECM must relearn the drivers habits. This may cause erratic shifting at first.

Good luck

LT