Flashed '12. Dead battery = CEL+Limp

Battery died in my wifes '12 yesterday. Still powered stuff, but wouldn't turn over. Replaced it with a Diehard Gold AGM. We now have a CEL and flashing glow plug light accompanied with ZERO boost. Nice.

I have a VagCom Hex+Can, but lent it out so used a Bluetooth solution to see a low voltage and overboost "historical" codes. Cleared them, disconnected the battery and hit the + to ground to drain any caps in the circuitry... no dice.

Let it sit overnight: Same crap. I have zero problem troubleshooting any mechanical or electrical fault, but this is automotive insanity.

Beyond that, it's my wife's car...

Time to grab the real codes and get your cable back. Cheap odb may not clear codes, hard telling.

How did the car drive before? Overboost may be boost hose blew, due to failed VNT actuator.

How many miles on the ride?

Just a thought, since I assume it was running OK prior... did you happen to knock a vacuum line loose in the battery area? Any loss of vacuum supply could cause a lack of boost. I would at least look the area over closely while you wait to get your VCDS back.

I had a similar limp mode/no boost once immediately after washing the engine bay at a car wash. It cleared itself after driving for ten minutes and shutting down. Somebody knowledgeable here recently recommended turning the key to the on postition for 15 minutes or so to reset some sort of ecu issue. Worth a try, I'd think.

Weird. Seems a line to the VGT was pinched. I never touched it, must have been when they replaced heat shields and emissions stuff under there. Super odd that it'd throw a code/limp after the battery went south.

Anyhow, I'm miffed that they're still charging me $120 for a problem that they caused.