I've been lurking on this forum for a few days now trying to diagnose my issue without having to go to the dealership, but I feel I might be at that point. Let's start from the beginning.

We live in Southern Louisiana and have recently been through a long cold snap. I don't know if htis makes a difference or not, but just keep it in mind. Wife started up car on Monday morning, after mostly sitting the whole weekend, and called me saying that the check engine light, traction control light, and brake light were on. Also the message center was saying check the VSC and Hybrid system. Wife brought it to Auto Zone to have the codes read and they told her it was a misfire in cylinders one and four and that the hybrid battery system needed to be replaced.

I searched on here and determined that it was the Aux 12V battery and decided to put the battery on a charger to get it back up to the correct voltage. Now, the lights are gone, battery is charged, everything is working right. BUT the electric motor is not kicking on. Car starts/runs/drives like normal, but when we are at a stop, the gas engine does not shut off. MPG is not good as well. I'm thinking this might be an ECU thing and it will just have to reset itself, but I don't know.

 

You can try a reset but several questions.

1) How long a trip has she taken? The extreme cold we have had will kill mileage...

2) If you have a check engine light, the scanners that almost any parts store will have will not pull the codes correctly from a hybrid. You will need a pro level or factory scanner to read them correctly.

3) Take a longer, 15 mile or so trip, come to a stop and see what happens. If the car shuts off after a 3 second stop, it is still warming up. If it shuts down after 7 seconds, you will be in full hybrid mode.

4) If you are running the original 12V battery, replace it.

5) After replacing the battery, either do a re-set per the manual or keep the car in acc mode with a memory save battery plugged into a 12V power port.

 

Ditch what Autozone told you.
You have to have those lights on permanently for day or 2 for DEALER to be able to read codes.
Start praying, hoping it's not brake accumulator failing on you next.
Do NOT forget. If it's COLD outside, hybrid drive will not engage. David is right, short trips - no electric mode.

David, is it true that 12V may cause VSC light? As you remember, I have that light come and go... But I am still on original 12V, and car was made late summer 2006. Battery is closing on EIGHT years.

 

Wife here.

This is what we have done so far. We have charged the battery and for a short time, the lights on the dash went away. Then we purchased a new AGM battery and for another short time the lights went away and things worked like normal. We found a copy of the service manual online and did a factory reset like it suggested. The warning lights went off.

Today, I decided to do a long trip, 25 miles or so. I did fine on the way to my destination. On the way back, I got to the second stop sign, two city blocks roughly, and the lights came back on. The car drives fine other than it won't go into hybrid mode. I'm getting pretty decent gas millage (30mpg)

I don't know what to do, I'm scared to death to go to the dealership.

 

30mpg is NOT a decent mileage.
We do not know, what year is your car and how many miles on it. All of this may still be covered under warranty. Hybrid drive is covered for at least 100 000 miles, or for 150 000 in CARB states.
Go to dealer. The very moment light comes up, just turn around and go there. Do NOT shut down engine or light may go away.
I brought mine in but mine is intermittent, "line technician" was not there and guy could not read any codes with hand held scanner.
That Camry basically MUST be scanned with a very advanced scanner, so one way or another, dealer is your best bet.

 

Would an ECU re flash solve the problem?

 

It is a 2007 Camry Hybrid with 143k miles. I live in Louisiana where my politicians are honest folk! We don't do emissions testing here.

 

Sorry for the delay, was in Atlanta helping my daughter.

To answer some of the questions, yes, the 12V battery can cause some of the problems noted if it is starting to go (battery voltage below 11.8V).

Second, if you have already put three batteries in the car, check the cable ends and connectors and make sure they are clean and make good contact.

This should keep the battery voltage off the car long enough to reset everything. If the light comes on again, you will need to get the codes scanned by a dealer scanner (Tech Stream) or an aftermarket scanner like a Snap-On Verdict, Verus, Modis or similar. To give you an idea, those scanners cost in excess of $5,000 (and some cases, $10,000) and are NOT what they use at auto parts stores.

The good news is that a local tech with a good scanner can read the codes and let you know what they are. That might cost $50 to $100 for diagnostics but then we can help get you started in the right direction if you come here and let us know ALL of the codes they found..

 

Hopefully your daughter made it out alright after that storm last week.

I've checked the cable ends and they are clean and tight and as far as I can tell, making good contact.

I will go to the dealer sometime this week and see what is going on. I didn't want to, but it appears that I will have to.

I will update when I get done with them.

 

OP, do not forget - you MUST have those codes on when you go there and do NOT turn off the engine, as this may reset codes.

Thanks, David. As you have noticed, I replaced my 12V. I'll report what happens.