quattro84

Update. After the spring the issues started again when outside temperatures rose. I got in contact with a German head mechanic working for VAG, after explaining my issues he immediately said: '09 chassis? We've had this before and in the end we replaced negative ground cable from chassis to battery. So I followed that and replaced that though no signs or damage and hey presto issues are gone since June. Part nr: 6Q0971235H - Wiring set for battery Hope this helps whoever gets into similar issues... It must be thermal and/or current load that's causing the internal resistance to rise. Static measurements do not give me indication of a fault. Terminal ends are clean and not corroded.

Well, all the gremlins are back. Some single trips can be without faults, or directly giving the same behaviour after key-on. Today a new intermittent fault: parking brake signal indicating it's on disabling ABS. Went away while driving. I am really wondering how this is possible, must be a central module transferring these signals.

50 amps was with all aux options on. Rear window heater, fan, blower, etc. Was reading in VCDS at that time the load indication was 50%. Cig plug reading was only 12.0v, haven't checked what it's showing with the new alternator.

Small update. In the meanwhile I've replaced the alternator completely by a genuine Bosch refurbished 90A one with 50mm pulley. The one I've taken off (which was bench checked by a shop) has a 57mm pulley but the plastic cover suggests it was 90A as well. But at least it means it was spinning at lower revs. Next to that got a tip to check the wiring underneath the battery box. Had it all opened up and cleaned, no trouble found up to / in to the bulkhead. As for now it hasn't occured yet, but it's gotten colder so hope it stays away.

Replaced the steering pump by a rebuild one. Issue still occurs. I am losing my mind. I am going to swap out the alternator even though the current one was tested. After a test drive of 3 miles (and setting the same codes while pulling op the driveway at idle) the alternator was pretty hot. Whilst swapping the pump I've checked all wiring and connectors --> fine. Checked the wire loom under those plastic covers beneath the battery, no trouble found.

No it doesn't.

I was just wondering if it could have linked it's feeds internally in the pump controller causing the circuitry to have the voltage drop. Adding other loads like lights, fan, blower does seem to make it stall quicker. And, just before the stall steering orange warning comes on (Think this is the 01288 MIL) but continues to operate. Only if you give it some more time/drive it will cause other modules to drop off. It will not recover within the same key cycle. After the stall it all works again. To me it sounds like some circuit needs load to heat up or something to make it fail...

Other theory: can the PAS pump controller internally short causing the other modules from that Kl30/15 feed to go offline? It only stalls while idling or motoring in gear while steering (so activated pump, sensor sensing motion)

The Netherlands. I'll be calling my local ex-Skoda garage next to ask if they have any idea on this topic. They still service loads on Skoda's and were able to help me before.

Alternator has been removed to be checked. Bench tested 3 times, came out OK. Wondering how to proceed now, how do I verify the signal from the ignition switch?

That is what I am pondering as well. I have logged the 44 group signals, and it shows it does drop while Idling and being high during the drive. At the end of the log I am parked/rolling in gear at 800rpm heavily steering to get it to stall. That is when it ends my log with stalling the engine. I am not sure how flat the clamp 30/15 voltage would be with a perfect altenator. Might pull it off again and have it fully checked, might be it has an issue.

Any clues how module J519 - Vehicle voltage control unit gets it power? Want to check which fuse and cable it's using, not finding it in kolhosniki.ru/elsaonline

I have checked the connection of the wire to the strip. It's clean. Checked resistance of the fuse and seems OK. Indeed, not checked under load. What can I try then, swap Fuse 5 with 6..? Do these blow often?

On the old and new it's 12.5-6V and 14.4V while running measured on the battery. Modules read 14.3 as well. Like said, with full lights/fan/aircon/blower on I managed to pull 50 Amps and it still read 13.7V.

And what precisely? Not sure where to start. I've logged the 44 - steering group, it reads 14.4V at idle and keeps high while I am steering like a mad man. I've logged up to 40A. It is all of the sudden all modules seem to see the voltage drop. I am wondering if my alternator (changed regulator only, rest not checked) is having issues. Both connectors I've checked and cleaned, voltage is 4.5V/11.3V at key on.