Jeep Grand Cherokee Owners: Need Help Fast!! Jeep is Sick and at Dealer's

In April I bought a 2007 Jeep Grand Cherokee Laredo 4.7L 8cylinder, 65k – I love, love, love this car! As in, I visit her at bedtime and kiss her dashboard goodnight.

Last night I went to the grocery store (a 3 mile trip), hopped back into the car, and when I tried to turn her over received these messages: “Transmission Over Temp” and “See Gauges.” She would not turn over and the electrical and security systems blinked out after my third or fourth try.

The gauges did not indicate overheating and the tranny fluid was topped off. I checked that the gas cap was on correctly and tight, all the doors shut, etc. It has been hotter than f*cking Hell in Jersey, but coolant is topped up and temp gauge hasn’t gone over the halfway mark, even last week when it was 104 and I made a 100 mile trip.

I waited and tried to start her again and received the same messages. I called the Jeep dealership to ask if I should jump the battery and they said not to do so, as it could cause damage (given the messages the car computer was generating).

I met the tow truck in the store lot this morning, Jeep was totally dead (no computer messages, no security/electrical functions). I tried my spare key in case this was a key-chip glitch – nada. Now she’s at the dealership having the diagnostics done.

A bit of Google research yields that this may be a glitch common to the 2007s, but the reasons and repairs vary wildly. Do my Dopers have some input? There’s no warranty, so this will be cash outta pocket here :mad:

Happy to report that it was just a dead battery, though the Jeep mechanics have no explanation for the transmission message.

$250 beats the heck out of the $5,000 I was envisioning for a new tranny . . .

wouldn’t surprise me if it was a software bug. 2007 is when Chrysler was in the thick of having their product line destroyed by Daimler.

A low or bad battery will have low voltage and create all sorts of screwy problems when the sensors can’t interpret things properly

A bug is my thinking – could a dying battery also cause a short that muddles the computer messages?

Oops, I just asked previous poster about this. This is my first “uber computerized” car with an electronic message display, so this little event really freaked me out.

I assume that I’ve been thoroughly ripped on the new battery’s price by the Jeep dealer (it’s a given that the labor fee is ridiculous), but a battery replacement at 65k is kind of expected, I guess.

Battery replacement after five years is commonly expected. Mileage is generally not a factor here.

Well, then, replacement is exactly on the five-year schedule! :slight_smile:

I would love to comment, but it’s a Jeep Thing, and I wouldn’t understand.

Touche! :smiley:

This. Low voltages drive computers systems nuts.

BTW $250 isn’t that outlandish for a good battery any longer. The days of a $29.95 car battery are long gone.

Wow! Maybe I haven’t bought a battery since the $29.95 days, because I was shocked when the service dept called me with the quote. Of course, in the bigger scheme of things, this car cost $2,000 more than my childhood house that my parents bought in 1974.

And Hershey bars used to be 25 cents.

Maybe a silly question, but if I’ve been driving around with a dying battery, could damage to the alternator have occurred?

Probably not, but who can tell?
If your alternator dies in 8 months will it be from the bad battery or because it is 6 years old? Beats me.

So you don’t have a crystal ball? Dang! :slight_smile:

I’m just happy that I’m out of my Nissan Xterra, which turned into the nightmare SUV around 90k (shudder)

If you battery looses capacity with age, the alternator will not go faulty as it is a constant voltage charger. The voltage out of the alternator is a maximum of 14.2 volts nominally. The battery loosing capacity would register fully charged at 13.8 to 14.2 volts and not accept a high charge rate from the alternator to get up to this voltage. Due to the loss of capacity in the battery, the voltage would collapse drastically when the starter motor needs high amps to crank the engine. 5 years is not bad but I have had some last 10 before failing.

I dropped my old one and the damn things are on back order. :frowning:

I think that I actually understand this! Well-written, Zep, thanks :slight_smile:

I hate when that happens, remember when crystal balls lasted a good 20 or 30 years?

Twenty-five cents?

Punk whippersnapper kid. I remember when they were five cents.