[drocketman]

There are three Parts to this thread. Yes, the Pacifica Hybrid is hard on 12v batteries, and this has been a debated topic. I now have cradle-to-grave data from a battery installed new in our PacHy in Jan 2019 and how the vehicle managed it for 4 years. That will be the second part of this thread.

First; What happened. Later, why it happened and finally, how I can fix my car so it should not happen again.

What Happened, recently (short version):

After 8 days of inactivity in our driveway, I found our beloved 2018 Pacifica Hybrid Limited completely dead and unresponsive to the remote on 1/4/2023. I manually unlocked the driver door, no usual dash indications, opened the hood and found the 12v battery system at 2.9v. As expected, it would not start and there were no responses or indications. There had been no warnings or indications of any problems prior to this (more on this later). The car prevented my 6 A charger from charging the battery while it was connected to the car. So I jump started the car with a known good battery, removed the jump, and allowed the engine to charge the car battery for a while. I decided to take no chances and replace the 12v battery. I turned the car to the OFF state via the dash push button. The car was never moved out of P park. I left it to go purchase a new 12v battery. I returned a little over 2 hours later with a new battery to find the car in the street, having rolled ~80 feet on its own and knocked over my neighbors 700-800 lb brick mail box across the street. A police report was filed, pictures taken, and I jump started the car with the new battery. It started normally and I backed it up under its own power into my driveway where I replaced the 12v battery without incident. The car has operated normally with no warnings or indications of a problem before and since this incident. While I was gone, the car on its own and while OFF had unlocked the transmission park pawl when the 12v battery was failing. This allowed the car to roll 45 feet down a very mild slope in my driveway (3/16”/ft avg), then across the street to crash into my neighbor’s mail box. There was no occupant, and no key fob was present. My quick search has found at least 3 other incidents with this same model, where the 12v battery failed and the car, on its own, unlocked the transmission allowing it to roll away. Of the 4 incidents I am aware of, 3 resulted in collisions and property damage.

NHTSA 11173732, also Pacifica Forum post: 528153, member: 64329 @AdrianaHybrid18
Brand new hybrid - completely died

Pacifica Forum post: 597914, member: 76986 @Inanni08
Battery dies on Pacifica Hybrid - Rolls out of driveway...

Pacifica Forum post: 543399, member: 66469 @luked1234
Battery dies on Pacifica Hybrid - Rolls out of driveway...

Kids play around here! and were nearby when this happened, but it was so quiet and slow that they did not notice. It didn't even trigger the motion activated video security camera across the street because it was so slow and moving towarrd the camera. It’s only a matter of time before someone is seriously injured or killed by this design defect. I have talked to my dealer about this but he suggests that I contact ChryslerCares first before they look at my car.

And for those who will ask: Yes, my wife and I have changed our behavior because of this incident. Normally flat-landers like us only set the parking brake when on a noticeable incline. The Pacifica has an inclinometer built in and does this automatically for us. But it is apparently not enough. With this car however, we now consider ALL surfaces as significant inclines and ALWAYS set the parking brake when turning the car off. This gives us some comfort, but consider that the parking brake is also under software control like the park pawl. Makes one wish for the days when we had a cable operated mechanical "emergency" brake that could be teased and under direct control of the driver instead of just a parking brake that we can ASK THE COMPUTER to apply and that is just ON or OFF.

I will make the car and battery available for inspection at the Dealer’s or Chrysler’s request.

I filed a police report. I consulted with my insurance agent and a lawyer. I filed an NHTSA complaint. And I have sent a PM to ChryslerCares.

We love this car, especially my wife. We use the heck out of it and it had 65330 miles on it at the time of this accident. But she has maintained it in showroom condition inside and out with regular hand washing, hand waxing and detailing. Prior to this incident, the car did not have a scratch on it and had never been in an accident. So she was livid when this happened and feels strongly as I do that this is a symptom of a dangerous design defect in the Pacifica Hybrid. Under no circumstances should a vehicle unlock the transmission on its own. There should be safeguards that prevent the haywire electronic behavior that causes this. Additionally, there should be a specific warning to the user that the 12v battery needs replacement. There is none. Those two topics will be the subject of the 3rd part of this thread. We hold little hope that Chrysler will fix the damage to our bumper, but that does not stop us from feeling that they should.

 

[CANADAHYBRIDGUY]

So let’s use this as an example with an electronic shifter and transmission . I if the battery dies you want the transmission to lock up to deter any movement ? , kinda strange because a battery can go bad anywhere . In a manual car you’d have to manually put into gear to negate movement , motorcycle as well . No power means no electronics , assists or safety features are present . If your house alarm fails and battery backup is dead you have no alarm , just saying . So if stellantis put code that when the battery goes dead to lockup the transmission , you’d grenade the internals and potentially die . So I think in hindsight common sense prevails for allowing any vehicle to have some kind of movement to get it out of harms way . So unfortunately you can’t have it both ways , and any vehicle has potential to move without power anywhere so bringing up scenarios like you have is complete conjecture .

 

[lacompas]

So let’s use this as an example with an electronic shifter and transmission . I if the battery dies you want the transmission to lock up to deter any movement ? , kinda strange because a battery can go bad anywhere . In a manual car you’d have to manually put into gear to negate movement , motorcycle as well . No power means no electronics , assists or safety features are present . If your house alarm fails and battery backup is dead you have no alarm , just saying . So if stellantis put code that when the battery goes dead to lockup the transmission , you’d grenade the internals and potentially die . So I think in hindsight common sense prevails for allowing any vehicle to have some kind of movement to get it out of harms way . So unfortunately you can’t have it both ways , and any vehicle has potential to move without power anywhere so bringing up scenarios like you have is complete conjecture .

You missed the boat, he is not suggesting the transmission should lock if the 12v dies. He is saying that a locked transmission should not unlock because the 12v dies.

I've personally always used the auto parking brake setting that engages with park. With my kids you never know, and these stories certainly confirms it's a good idea. I'm so sorry the OP had to go through this, hopefully more folks that have this happened file reports.

 

[drocketman]

You missed the boat, he is not suggesting the transmission should lock if the 12v dies. He is saying that a locked transmission should not unlock because the 12v dies.

I've personally always used the auto parking brake setting that engages with park. With my kids you never know, and these stories certainly confirms it's a good idea. I'm so sorry the OP had to go through this, hopefully more folks that have this happened file reports.

Bingo! I couldn't have said it better myself. And thanks for the tip on the Auto Park Brake setting. I just went out and found it in settings and applied it.
Previously our pacifica (and I suspect all of them) must have an inclinometer built in. This is because when parking on a steep incline, it set the parking brake automatically when placed in park, but did not set it when on a moderate or low slope surface. I'm guessing this is to protect the park pawl mechanism from being over-stressed.

 

[PacDave]

So if stellantis put code that when the battery goes dead to lockup the transmission , you’d grenade the internals and potentially die .

As someone correctly stated, no, we don’t want the pawl to be automatically engaged when the battery dies. We want the pawl not to be disengaged. In fact, I’m pretty sure that engaging the pawl while the car is moving would not be as catastrophic as you suggest. There may be some internal damage if this happens but it’s doubtful that a parking pawl engagement would kill you. I remember a guy in my youth who jammed his transmission into park while driving down the road. It made some clattering noise but did not lock up the wheels or kill is.

 

[Kenbenezer]

I agree, a transmission, that is in park, should stay in park. I use the electric parking brake, all the time. Just a habit from driving manual transmission vehicles.

But FYI for the community -
The electronic parking brake on the rear wheels is power activatied and power de-activated. This means a 12v battery failure after you set the e-brake, means you can't release the brake manually. A jump will be required.