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'05 Magnum: Won't recognise keys after battery disconnected/reattached...

13K views 6 replies 4 participants last post by  djc208  
#1 ·
At this point I'm going to have it towed into a dealer unless someone here can help me.

WHAT HAPPENED:
I installed the towing bar & harness this afternoon. Per the instructions I disconnected the battery while installing the harness. It was probably disconnected for a couple of hours.

Finished the installation, hooked the battery up & tried to start it. For the first 2 or 3 tries it would start, run for a couple of seconds then shut off.

I decided that maybe the ECU hadn't properly initialized after reconnecting the battery, so I disconnected the battery for about 5 minuites & then reattached it.

Things were even worse, now it wouldn't even crank!!!

When I turn the key, the check engine light, security light, & electronic throttle lights stay on. Then after a few seconds the security light would start blinking...

About then I realized that the key's remote loc/unlock buttons didn't work. Got the 2nd key & yup, it didn't work either.

Called a Dodge dealer & asked if a tech could give me some advise on how to reset the system & was told "all my guys work flat rate, I can't have them giving out free advise over the phone". Called another dealer, they tried to help, but it came down to they needed to plug in diagnostic equipment to figure out what's wrong.


Searched DodgeTalk, & this pretty much sounds like this thread:

My magnum is fubar!!!

Where a ECU re-flash was required...

So tomorrow AM I"m calling the Dodge roadside service number & having it towed as I'm out of ideas.
 
#2 ·
I have no idea at all, but I am very interested in what you find out. Keep us posted.
 
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#3 ·
On Tow Truck...

Dodge Roadside Support was very nice & got a tow here promptly.

Called the dealer & was told that security system, engine control reflash & key reprogramming was a $79 charge that is NOT covered under warranty/service agreement.

One of the threads said that there was a service bulletin out for this battery disconnect problem. I called Dodge Roadside Support Customer Assistance & they searched the FSBs & didn't find anything.

They told me that my Dodge Warranty & service plan do not cover the re-flash charges 'because it was caused by my action disconnecting/reconnecting battery) & not by a 'component that failed in normal use'. Tried arguing that battery disconnect/reconnect constituted normal use but didn't win that one either. Neither did arguing that it was due to the Dodge installation instructions explicitly rrequiring battery disconnect/reconnect. ( : { )

IMHO,
This is really poor design, the programming should be stored in flash memory & reloaded on power restoration, but I'm just an EE with 37 years of experience designing computers & operating system software ...

I bet they end up not covering the towing charges either!
 
#4 ·
The programming is stored in flash memory and should have worked just fine after reconnect. Only certain non-vital things are stored in volitle memory and are lost on battery disconnect. This is a defect in the vehicle and probably why the flash was required. They might argue that the battery disconnect/reconnect scrambled the computer and messed up the programming but that's probably reaching.
Fact is it shouldn't have happened, and you probably would have had the same problem if it had been a dead battery and they came to give you a jump, at least then it would have been their fault for sure.
I'd ask them to dis-connect and reconnect the battery and see if it happens again. Maybe there's a problem with one of the computers in the car?
 
#5 ·
your magnum has something called SKIM...it is a anti theft system that is programed into the keys...and if the vehicle doesnt see the right key in the ingnition after three tijmes of starting it... the computer will lock everything out for 3 hours...then you get a chance to program the keys via starscan(the dealer has to do this)...after three times of starting it it will show no sign of cranking or anything until you wait three hours and put a key that is recognized by the computer....i think mopar is the only people that do this...so in order to steal a new jeep,dodge, or chrysler you have to have a $600 key and have it prgramed to that VIN

-Jesse-
 
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#6 ·
So it's 3 strikes & you're out with SKIM...

Well, SKIM didn't recognise the 2nd key the next AM, so at 8:30 AM it was towed to the nearest dealer (14 Miles away, across the state line!). The dealer finally put a tech on it at about 2:00 PM. It was ready to go at 3:30 PM. Paid a $79 re-flash fee & drove it home.

The service manager said that they have a 'special machine' that they have to hook up before disconnecting the battery to avoid this problem.

Only good thing is that the power moonroof has never quite stopped in the right position to seal properly. They 'recalibrated the moonroof' Said they'd never seen one loose calibration over a battery disconnect before. I just thanked them for spotting the problem & taking care of it.

I still think it shouldn't have forgotten the key on reconnect.

Took a long (4-hour) drive the next day. Gas mileage was much lower than I've been getting under similar conditions, but seemed to improve as the day progressed. Could some ECU self-tuning have been lost?
 
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