Audi A6 Error 01117: Load Signal Fault

Hello forum!

I need your help.

I'm currently working on an Audi A6 with a 2.5L TDI AFB engine / Tiptronic transmission. (Manufactured in September 1998, 244,000 km).

Recently, shortly after starting the car, the transmission has been going into limp mode while driving, and the ESP warning light has been turning on.

The diagnostic scan revealed the well-known error code 1117, as well as an error entry in the ABS control unit.

01117 027
Load signal for generator terminal DF.
implausible signal


Error in the ABS control unit (also in the...
Transmission control unit.

18265 035 P1857
Last signal.
Error message from the engine control unit.

I then had the Lima (alternator) rebuilt, but the problem is still the same. The wiring also seems to be fine.

'The interesting thing is that the charging voltage of 14V is present when the engine is running, and that the error itself is logged after a few seconds, even when the engine is not running (only the ignition is switched on).'

Does anyone have any idea what this could be?

I found some threads about this in the forum, but no one actually wrote down what it really was.


I am grateful for any advice.

Regards,

Knubbi.


P.S.: Just another piece of information: The error occurs exactly 10 minutes after the system is turned on, regardless of whether the engine is started or only the ignition is switched on.

I suspect that the error entry does not represent the actual error.

I found the error, thank you for your help.

Regards,

Knubbi.

knubbi wrote:

I found the error, thank you for your help. Regards, Knubbi

Hello, could you please tell us where the problem was?

Thank you very much.

The alternator regulator was defective.

knubbi wrote:

The alternator regulator was defective.

and then the transmission goes into emergency mode?

Yes, exactly.

Because the motor load signal can no longer be calculated correctly. The lighting machine load is a component in the calculation of the motor load.

knubbi wrote:

Yes, exactly. Because the motor load signal can no longer be calculated correctly. The lighting machine load is a part of the motor load calculation.

Quote:

I then had the Lima rebuilt - but the same error persisted. The wiring also seems to be okay.

And what did you have serviced at LIMA?
That load signal issue is quite something. In this case, the solution was even stored in the error memory.
Load signal for generator terminal DF.
implausible signal

I simply replaced the regulator. Before that, I ran the machine on a Lima test bench here at our company. The regulator itself was working perfectly. However, that has nothing to do with the function of the DF terminal.

I also used to get the "DF" error message in my Golf from time to time.

I couldn't detect any effects whatsoever...

m;

In my case, it was obvious. When two lights come on in the cockpit and the transmission only engages up to the 4th gear, then you can definitely talk about noticeable effects.

dieselmartin wrote:

I also used to get the DF error from time to time in my Golf. I couldn't detect any effects whatsoever... m;

The load signal only affected the automatic transmission.
For comfort reasons, the brake couplings will be controlled more gently in the partial load range.


For example, in the case of a V8 engine, the load signal comes from the engine control unit (ECU) via the mass airflow sensors.
If these components fail, the transmission can very quickly become damaged.

Quote:

For example, in a V8 engine, the load signal comes from the engine control unit (ECU) via the mass airflow sensors.

Yes, but what makes me wonder is why the "clamp-DF" signal is so important for load calculation in a TDI system.

He is quality-controlled, and the engine control unit (ECU) knows the injectionmass (and not, as with a gasoline engine, some arbitrary time) and the speed. What more could one want for an accurate load calculation?

He probably wants to calculate the torque transmitted directly to the transmission, but for that, he would also need to factor in the air conditioning and power steering.

Now you've answered the question yourself...