mdfa4

Looking for some opinions here. Like many others in the past, I left my interior light on (actually, my son did) and the battery went dead. I attempted to jump it, but it did not want to start. I ended up replacing the battery, it would not hold a charge.

Now I have the typical problems that should be fixed by resetting the codes and doing the throttle body adaptation. The car will not do the adaptation on it's own, so I ordered a VAG cable from Ebay.

The cable and software work fine on my wife's '00 Beetle with the same 1.8T engine as my '98 A4. I cannot get the ecu on the Audi to respond at all. I always get 'no response from controller'. I also have a generic OBDII reader which only gives me "E" for error. I know that the Ebay cables are not always the best, but the fact that it works on the VW and that I also get an error on the generic reader leads me to believe that I blew up the ECU when I jumped it.

Any thoughts or opinions?

thewatcher101

Take out the ecu and open it up to check.

diagnosticator1

Does it start and run or not?

RKA

ECU is probably fine. Find someone with a known working cable, and try adapting it.

Ertman

If not, then your ECU is bad.

mdfa4

The CEL does come on. The car will start, barely, You have to feather the throttle when starting it, then it will start, then die a few times before it will stay running. Once it's running, it idles at 400 RPM, when you give it throttle, it nearly dies, then revs to 3500 RPM. It won't run anywhere between 400 and 3500. When it's running, the CEL is on.

I've opened the ECU and don't see anything obvious as far as burned spots on the board or 'popped' components.

Is it possible to kill just portions of the ECU? If it's not the ECU, why will two different readers not connect? I suppose there is the possibility that the connection between the connector inside the car and the ECU is bad.

Anyone have suggestions on someone in the Kansas City area that can test the ECU?

Ertman

Quit ****ing with it!!

You need to do a TBA, the old school way.

Pull the cable off the negative side of the battery, leave it alone, come back in ten minutes and re-connect it.
Now put the key in the ignition, do not touch the gas pedal and turn the key to the on position, leave it there for TWO (2) minutes (120 seconds). If you listen closely, you will hear the Throttle Body Adaptation occuring. After two minutes, turn the key to off.
Now crank it up and tell us what it is doing.

mdfa4

I've already tried disconnecting the battery on several occassions - sometimes up to several days. I've also pulled the ECU clear out, not that pulling the ECU should work better than just disconnecting the batter, but it made me feel better. I just tried it again this morning. It still will not do the TBA.

I found someone on another board who had the same problem. I guess sometimes the ECU will set a code when the ignition is switched on which prevents it from doing the TBA.

So, I need to reset the code, then manually do the TBA with the VAG, except I can't get the VAG to communicate with the ECU, so I'm stuck.

I guess my next step is to find a shop with a good VAG that is also close enough that I can limp the car to it, unless someone has a better suggestion.

Ertman

pull it down and see if you are getting a good connection.

You may have a fault at the throttle position switch in the throttle body that is causing the TBA to fail. The easiest way to check is to remove the throttle body and clean it. The switch will generally reset then.

Im@wesome~ out!

shows what you know :P... i didn't have to replace the ecu.. twas fine