[CRC]

So when driving first thing in the morning to work, about 10 miles, the car runs seemingly fine, on my way home it usually drives fine until I get almost home the it starts to spit and sputter. when I push the clutch in and let it go to idle it dies. I have to start it with my foot on the gas to keep it going and have to fight it the rest of the way home and the exhaust smells rich. Until yesterday no lights would come on. Yesterday the EPC light came on along with the ASR/EDL light (circle with triangle warning sign). And the car seemed to be cutting off and on while driving at highway speed.
this is what I have done so far:
-Tried scanning the car with a craftsman scan tool 87702, it comes up with an error message. no aftermarket stereo but removed the K-line from the stereo anyway. still no luck.
-Checked fuse 12 and changed it out with new. this fixed the problem just long enough for the scan tool to read one code. I grabbed a piece of paper to write it down and before I got back it stopped working. tried changing it out again no luck.
-Checked pin 4 to ground have .5 OHMs
-checked pin 7 for volts have 10 volts
-I have been tracing wires to check for damage no luck.
I don't have a Bentley so I am kind of stuck now. I have done a ton of maintenance on this thing but I am at a loss to what else to do to get the scan tool to work. It still works fine on my truck so I know its good.
Just to kinda speed the process along, the battery is connected the ignition switch is on while using the scan tool. No visible damage to any fuses and have checked many of the fuses with a multi-meter. I am a mechanic, but I work on industrial diesels for a living and neighbor’s cars every now and then

 

[esse10]

scanner

These new beetles electrical can get pretty tricky even for an experience mechanic. If you can drive the car take it to autozone and use their scanner and see of you can pull codes. From the symptoms you just described It sounds like your car might have a clogged up gas filter. Did you check all the fuses mounted on the battery fuse box? You sure the battery is good? do you read 13-14 vdc battery voltage while at Idle? You can't troubleshoot if you have no power to the battery so I would start there.

 

[CRC]

I just replaced the battery around 6 months ago. I ordered a Bentley service manual 2 days ago, so hopefully it will help me figure it out. The thing that gets me is the OBDII not working. I'm pretty sure the port to ground, I believe pin 4, is what is causing my issue. .5 Ohms seems like a lot unless it doesn't go straight to ground (which I hope the Bentley schematics will tell me). I have had so many issues out of this car its driving me crazy. These things are electrical nightmares, the parts are insanely expensive and the cars hold no resale value. anyway, I should have the manual by this weekend so we will see.

 

[esse10]

ground

Yea but from what you described it sounds like your battery got drained overnight or something.
I think I read a thread some time back about folks OBD port not working and they had to disable the after market radio or something like that you might want to do a google search on that.

I believe .5 to ground is reading chassis ground on a digital meter. Measure from the car's negative battery to chassis ground, should be around .1-.5 If you have a relativity button on your digital meter here is what you can do; connect the meter leads together and push the relativity button and the reading should go to zero, and I mean 000. Then use the meter to measure a difference in ohms between two points. Just don't forget to reset the meter back to normal state. But yea .5 is measuring almost a strait short to whatever reference you have the other lead connected to. Good luck man.

 

[billymade]

This might help:

Ross-Tech: VCDS: Afterrmarket Radio Problem