PMrider

My mechanic is telling me it is the ECM (same as ECU I imagine) that is malfunctioning. They can't even get it to talk to them. Is this typical after a REVO flash? They are going to replace it to see if they can then diagnose the cause of the parasitic drain on my battery. Has anyone had this happen to them? I guess I will have to go back to REVO with the new ECU. Luckily everything is still under warranty and won't cost anything.

kodeTT

and also, may refuse to do anything about it. so tread lightly.

TTschwing

May be a Red Herring in sleuthing down the problem. That's probably the result of the REVO flash and not the real culprit. Several here have fixed Parasitic drains with a cluster replacement.

joe@vwvortex

hamper this.

kodeTT

and ask if you are chipped before doing so. i would most likely say no and let them flash your ECU, then go back to REVO and reflash. otherwise, they will be on to you regarding chipping, etc. as long as you go there.

joe@vwvortex

my cluster was bad when I went to get GIAC flashed - took 7 tries before it finally got through. At the time I didn't know my cluster was bad - but upon reflection and discussion with the guy who flashed my car - it was the bad cluster that caused the problem.

Sully

So would a battery drain then combined with erratic cluster problems cause a drop in Revo performance? In other words...could a malfunctioning battery affect the ECU/Revo? As many of you know, I have eluded to some effect some time ago that I feel there has been a drop in the boost of my Revo Mod. Have a hard time believing it could be timing belt related, and often wondered if the Revo software is working properly because of a possible battery drain and malfuntion on the cluster. Is it possible at all for the Revo program to completely dissapear or at least loose its optimum function (like bad sectors on a computer hard disk)?

TTschwing

But software can get corrupted. Voltage issues could be contributing factors...

Sully

but then again, I am not real trusting in this shop. Seems to me if the ECU could take a hit from poor voltage then Revo maps would get a little skewed. I am not so sure that I have a bad cluster as much as I have a bad battery that I bought new. Every time I start it up the cluster resets itself. Did the same on the old battery which lends a "little" credibility. BTW, I never was clear on how CEL's worked. By that I mean whether to check for CEL's while car was moving or just when I put the key in the ignition before start up. Turns out that as memory serves me, I have had several CEL's. Time for VAG.COM! Funny that when I had my car worked on for the suspension overhaul, they couldn't find any record of CEL's?

TTschwing

Cluster resets on starts are usually a bad battery, but could be heavier draw from a failing starter.

CELs are stored in the ECU and can be read by a VAG. The record doesn't go away until cleared.