Too many communication errors (VagCom)

TDI_Michael

Veteran Member
Joined
Feb 25, 2002
Location
Louisiana
TDI
01 Golf GLS
Just finished doing the timing belt on my 01 Golf and went to check the timing by going to 01-Engine, 08-Meas. Blks, Group 000, Switch to basic settings, then TDI timing. By the time I get this far (most of the time it happens when I get to group 000 or basic settings) I get the alert VCDS: Session Unreliable Too many communication errors to continue. I have tried restarting the computer, Uninstalling and reinstalling the VagCom software, going through the computer and disabling most everything that might possibly conflict with VagCom (computer is only used for this program so really not much is on it anyway). I have used this computer for over a year (once every few months really) with Vag Com and it has worked before. It is a Compaq Presario 1655 with 96mb ram running Microsoft Windows Me. I have a Hex-Com serial connector bought directly from Ross Tech many years ago. When I went to do the timing I had version 805.4 but the first thing I noticed was a pop up stating that a newer version was available so I downloaded the new version (908). I did a search and I see that this problem has occurred before but I don't see a definite solution posted. Anybody have any ideas on this?
Thanks,
Michael
 

TDI_Michael

Veteran Member
Joined
Feb 25, 2002
Location
Louisiana
TDI
01 Golf GLS
The car battery is good but I know the laptop battery is shot. I have to use the AC adapter to run the computer.
 

That Guy

Veteran Member
Joined
Jan 23, 2009
Location
Edmonton, Alberta, Canada
TDI
2001 MKiv Golf TDI
I had similar errors. They would pop up once in a while and over time got worse.

(It also got worse when it was really humid in the garage. ... from snow melting off the cars in the winter)

My fix...

- changed the battery...it was old.
- cleaned all grounds....the one under the battery was corroded up...the others were okay.
- cleaned all the electrical connections I could get at....and since then I clean any others that I come across whenever I do work on the car.
- cleaned connector on the ECU...under the windshield
- cleaned the VAG cable and plug
- and used dielectric grease on all of them (keeps moisture and crap away from the connectors)

I did the cleaning with that electrical contact spray and isopropal alcohol (99%) and foam swabs.

For the corroded ground and battery cables I used a really hot water and I think baking soda mix. (I also put the grease on them after cleaning....although you can buy specific stuff for the battery terminals.)

So far...no more problems. :)
 

rideage

Active member
Joined
Nov 24, 2009
Location
UT
TDI
jetta
I had that same problem just a couple of weeks ago... I ended up trying several things... but I think the one that solved the prob for me was disableing the firewall on my laptop... I used VCDS a couple of months ago and it worked fine... but I guess sometime after that the firewall got changed somehow... So that is something to check for.
 

TDI_Michael

Veteran Member
Joined
Feb 25, 2002
Location
Louisiana
TDI
01 Golf GLS
An update to this problem. I tried cleaning all the grounds and battery terminals on the vehicle but had no luck. I dug out an old IBM Thinkpad laptop I had all but given up on (32mb ram, Windows 98 and a hard drive of less than a gig) and installed the new version and it worked perfectly. I don't understand as I have not installed any other software on the computer or use it for anything but Vagcom but I'm just happy I'm up and running again. Thanks to all who replied.
Michael
 

flakrat

Well-known member
Joined
Apr 13, 2005
Location
Birmingham, AL - US
TDI
Jetta 2005 TDI Wagon
SOLVED for me, thanks for whomever posted above about not plugging the laptop into a cigarette lighter power inverter. That was causing completely flakey connection issues.

Unplugged the power and now I can log my engine 003 group data :)
 

Uwe

Vendor , w/Business number
Joined
Feb 24, 2000
Location
Lansdale, PA, USA
SOLVED for me, thanks for whomever posted above about not plugging the laptop into a cigarette lighter power inverter. That was causing completely flakey connection issues.

Unplugged the power and now I can log my engine 003 group data :)
What kind of power adapter is this? Details would be great.

-Uwe-
 

Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
It's always something, isn't it? Once you figure out that one thing that has been chaffing your hide, it mysteriously turns out all good.:D
 
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