"ACC Error" in dashboard.

[Greyvrsthree]

For information in case it helps someone else.

 

Throughout the (7 year) ownership of my Octavia VRS it occasionally displays the crash warning symbol on the Maxidot display.   Big red Car on squiggly lines if you have not seen it. The other day I was accelerating under full power onto a roundabout directly toward to disappearing tail of a leaving driver. Up comes the warning. Only this time (after the car had consumed a stiff whiskey), an "ACC error" fault appeared and would not clear. I phoned the dealer to be told that the car would be required for a three day diagnostic and they had a slot in three weeks. I then phoned by local independent and he slotted me in that lunchtime. 

 

The purpose of the post is to say that we discovered (he and I) that there are 20 crash warning position counts available in the register and once these are consumed the code decides there must be a fault and will disable the ACC. Only the proper VAG software can clear this condition, not Ross Tech (he said).  and it cost me £30+ VAT for the annoying German bungle. I dread to think what **** and bull the main dealer would have spun (radar realignment etc) for the three days and the cost. 

 

So it is worth having a rough mental note of how many times you have encountered the crash symbol and having a plan to clear it for a reasonable cost. My irritation comes from the lack of testing in real world conditions of the code behind the ACC crash detection. As a programmer myself I write allot of test code to test my release code, clearly VAG never tested anything with parameters which approximate UK south east driving conditions / congestion !