Ok... so I did an ECU flash that I got from Vivid Racing. They require that you have your battery on a tender for the process, just to be sure that there are no electrical interruptions. I have a Black and Decker battery minder that I set to the 12 volt position and plugged into the 12 volt receptacle in the console.

The problem began after unhooking everything. Once I turned off and removed the key, unplugged all the equipment and started the car, I got a red error code on the dash... "Warning Battery/Generator". Everything else seemed just fine. The car started up and runs/drives terrific.

I hooked up my Durametric cable and ran a diagnostic, which brought up the following code information:

Bosch Digital Motor Electronics Motronic 7.8.1
P0621
Charge Indicator Light

Just as a test, I reset the code, turned off the engine and pulled the key out. Then restarted the engine, and the warning came right back, so I am sure that there is a problem... I'm just not sure what it is. The car is throwing no other codes. I also took a look at the fuse box and found no blown fuses. I Googled the code, but all I could find are other people that have had the code show up with very different situations than mine and some VERY general information. A search on our forum brought up nothing useful as well.

In the morning I'm going to start the car again and put a multi-meter on the battery to make sure that I am getting a good charge from the alternator. My battery is brand new, (a week old, replaced simply as a PM item), and the car was just recently at the dealer for a general check up/oil change. At that time, they cleared a false SRS code that had been active for a while, so I know that they had the diagnostic equipment hooked up and surely would have said something if they had found a fault in the system.

Please help, Obi-wan Rennlisters, you're my only hope!

 

P0621

Battery warning light

Diagnostic conditions
--Engine running
--Normal driving for 2 minutes

Possible fault causes
--Open circuit in line between generator and DME
--Short circuit to ground in line between generator and DME
--Short circuit to B+ in line between generator and DME
--Generator faulty


probably the first cause listed above is your problem? that flash might be faulty/telling the ECU there is an open circuit...?

good luck and please post your result if you figure it out.

 

I'm a bit taken aback that the key was left in the ignition during this ECU flash process unless of course this was as per the flash process directions.

If not... was the key left in the on position?

Other than that my WAG is when you disconnected things there was a power interruption.

In older cars -- my 03 Turbo for instance -- a power interruption can result in one or more error codes which is related to the power interruption. There can even be a steering wheel position sensor error.

The last time I replaced the battery in my car I just made sure everything was off then disconnected and removed the old battery then dropped the new battery in and reconnected it.

There were no error codes. When I had my work double checked by the techs I was told that sometimes the error codes appear sometimes they do not. Even if they do while they can be cleared by the Porsche diagnostics computer they'll self clear after the car is driven a bit.

In the newer cars they are almost certainly more sensitive to any power interruption, no matter how brief.

 

Macster... Here are the flash directions as given to me by Vivid Racing:

"1. Place the car on a battery charger of at least 10amps and up to 40amps. The battery must be fully charged before any programming is started !!!! A car that has been sitting for a couple of weeks would not have a fully charged battery.
2.Plug the Laptop is in so that the battery is charging while programming, should you not do this the computer can shut down and cause damage to the DME.
3. Make sure that your computer is booted up with No anti spy ware, IM or anti virus running These programs can launch at any time.
4. Check to make sure you have an Internet connection by checking a link to Http://www.Softronic.us
5. Plug the cable into the laptop and then the OBD2 port or also called the diagnostic port and then turn on the ignition. MAKE SURE it is fully plugged into the OBD2 port! DO NOT bump the cable while programming! In fact DO not sit in the car. Place the laptop on the seat and plug in the cable.
6. Double click on the Tuned file that you downloaded.
7. Do not change to slow, keep the program rate at fast as it defaults.
8. The program will start and run, you can watch the status bar on the bottom. This will take about 5 minutes. DO NOT open any other software or re-click start etc.
9. The program will say "Finished and cycle the key " when done.
10. At this point turn the key off, unplug the cable and start the car.
11. Ride and enjoy!"

As soon as the flash was completed, I turned off the ignition, unplugged the cable, unplugged the charger, put all the equipment away and only then did I start the car.

 

First,I'd contact them and ask about this problem. Most likely they've encountered it before.
Then,you can always drive the car,let the computer run a few cycles and it might clear by itself.
Good luck!

 

Absolutely... I've already been in contact with Vivid... waiting for a response now. I'm going down to start the car and put a multi-meter on the battery to check the charge from the alternator. I think I'll pull the negative cable after that, and then hook it back up and take it for a drive.

 

The DME needs to run a few cycles no matter what. After you disconnect the battery or clear any code the DME will automatically set all monitors IM to the ' NOT READY ' status. Then the car needs to be driven in different conditions : stop and go traffic,highway etc....until those monitors are switched to ' READY ' status. The same might be true for that error you're getting...the DME might need to test the battery charge under different conditions(like under load and different consumers : heat,AC,lights on etc)which can be achieved in real driving only.

 

Good points... Vivid wants me to re-flash the ECU to stock, cycle the key, and the flash again to the upgrade. Also, after the fact, he tells me that his tech said that the charger should be connected directly to the battery, as they have experienced issues when the charger is plugged into the console receptacle... thanks for the heads-up Vivid.

 

I was just wondering, what kind of gains one would get from this fiasco?

 

Did some running around today, and then checked the voltage while idling... solid 14 volts. Still have the error. I guess I'll have to try what Vivid suggested and flash to stock and back.