rasch_C

I have a '94 S4, now with a check engine light, that I have been unable to get my VAGCOM unit to connect with it. I've been left with diagnosing the diagnostics port after talking with Ross-Tech.

Considering I live in Northern Wisconsin, and do not have a garage at our current place, I would like to just be able to check the code and deal with the check engine light.

Is there an alternate way of pulling the codes on these cars? I know on some other older cars you can check them by turning the ignition on 3-times quickly, then it flashes the check engine light in sequence of the code numbers. Is there such a thing I can do here?

Thanks

UrS4boy

Not sure what Ross-Tech told you but you need their 2 x 2 adapter:

http://www.ross-tech.com/vag-com/2x2.html



With the adapter, you can connect to the black and white connectors in the relay panel under the hood. Otherwise, you can use those connectors to blink out the codes:

http://www.sjmautotechnik.com/troubl...f20v.html#fcs4

http://www.sjmautotechnik.com/troubl...g/20vcodes.htm

rasch_C

I already have the 2x2 adapter. VAGCOM works with my A8 just fine, along with all the other VW/Audi vehicles in my group of friends.

When connected to the S4, VAGCOM does not recognize the interface as being plugged into car (yes, w/ car running), and the LED on the interface does not light. Voltage on the black (power) connector checks out fine. I can even light-up a test light through the 2x2 connector.

I believe I have a problem through the white connector side of things (k-line and l-line). I will look through the links provided and maybe give it a go tomorrow. But, if the only way I can blink the codes is through the diag port, I don't have faith in that working at the moment.

Thanks for the reply!

scarman

Dave's photo of the underhood relay box with the 2X2 connectors should give you a place to start. It shows the connections for the wires from the white and black connectors. Make sure those are intact and tight.

rasch_C

Blinking it worked. Thanks! I have a blink code of 2324 which indicates an issue with the MAF circuit.

I will investigate this the first chance I get. Although, I have a hunch it may just be dirty. I just replaced a thermostat that was stuck open -didn't realize until it started getting colder out and the engine wasn't warming up. I got the check engine light about the same time, when it started getting cold. The engine has also been stumbling out at idle when cold.

My initial thought, after realizing the engine wasn't warming up, was that maybe the cats not getting hot enough to burn off. But now, after fixing the t-stat issue and not seeing an improvement, and having this code, maybe the MAF wasn't burning off because the coolant wasn't getting hot enough to engage that.

It's just a hunch. I do have the Bentley for all my vehicles. So, I will follow the outlined diagnostic procedure in there.

Thanks again for the help

UrS4boy

Click on the G70 Mass Airflow Sensor label in this diagram (all the other labels are "hot" links as well - for future reference):

http://members.shaw.ca/speedtek/UrS%...ice%20Map.html

scarman

Dave has provided you some great info in the post below. Note for instance, how thin and fragile the hot wire system in the MAF is, and treat it gingerly. Note that since the wire has a burn off proceedure that it is probably not the issue itself, but the connectors or circuits inside.

Bentley will provide invaluable information on diagnosis and repairs, but it will not make you a tech. The manual assumes some level of Audi experience. This forum can help fill in the holes some as well.

rasch_C

Yep, it is good information and a good read. This isn't my first rodeo diagnosing MAF circuits -at least they give better check procedures than the new ones. I have always had an Audi in the stable my whole driving life (starting w/ a 5000 S, and most recently my A8 of 8 yrs, and this S4 that I adopted from a buddy ~1yr ago) and am fully confident in working on them. I have done everything from plugs, alternators, tune ups and timing belts, and recently just finished doing head gasket and rebuilding the top end in a rover 4.6 to swap into our Discovery.

The turbo 5 is new to me, but I feel I have a good base, and enough sense to seek more specific resources on it when it gets unfamiliar or unclear.

Cheers