Yesterday I drove down a steep, icy hill with several tight bends.

 

It turns out I had misjudged just how icy it was and, I hold my hands up, I was going too fast! First gear with my feet off the pedals was picking up too much speed to go around the corners, so I had to use the brakes quite a lot all be it barely touching the pedal.

 

After a couple of minutes, ABS/ESC lights came on and the ABS stopped working, and the power steering light came on.

 

I assume the car thought it must have been a fault and disabled the systems (not what you want when you have more hill to descend and more bends to negotiate!). I ended up having to go old school and actually drive!

 

I guess I just want to check to see if this is an actual fault or if this is what it's supposed to do.

As with any fault light, the first thing to do is to read the codes. Then you can interpret them and fix the issue.

 

It may have been a sporadic fault but you don't want it happening again

Edited 3 March, 20188 yr by SuperbTWM

Thanks - there were so many I can't quite remember which one's were lit. Maybe I need to buy one of those code readers.

 

One thing I didn't mention was that once I got onto normal roads, within a couple of minutes (it wasn't instant), all the warning lights went out and everything returned to normal. It's been fine since.

When the ABS system detects a wheel under rotating it cuts the braking pressure to that wheel allowing it to rotate again, we are talking milli-seconds here.

It checks that the wheel is rotating normally again then re-applies braking pressure.

 

In icy conditions there may be insufficient friction between the tyre & icy surface for the wheel to start rotating quickly enough, it may take a few seconds.

The ABS system then assumes there is a fault so disables itself.

 

It is constantly self-checking so when conditions returned to normal it re-activated.

But if you get any sort of repeat under normal conditions there could still be a problem which will need codes read.

 

 

1 hour ago, Magicdrshoon said:

 

It turns out I had misjudged just how icy it was and, I hold my hands up, I was going too fast! First gear with my feet off the pedals was picking up too much speed to go around the corners, so I had to use the brakes quite a lot all be it barely touching the pedal.

 

Actually just using the brakes and dipping the clutch (with the help of ABS etc...)  on bad ice can be much safer than using engine braking. If it's very icy under engine braking it's possible for the driven wheels to effectively skid - in that under engine braking the driven wheel falls back to tick over speed but the icy ground under the wheel is travelling faster - you loose control of the steering at this point!

 

Back in Feb 2001 when I was selling my old Passat (ready to buy my Octavia that I still have!)  I nearly ended up in a ditch because of this, fortunately dipped my clutch and got a teeny bit of control back. Was a really bad road as there were 4 other cars lined up in the same ditch!

 

There is a reasonable chance that the really bad conditions gave the ABS some "implausible" signals and just confused it

 

 

 

 

Edited 3 March, 20188 yr by bigjohn

4 minutes ago, bigjohn said:

Actually just using the brakes and dipping the clutch (with the help of ABS etc...)  on bad ice can be much safer than using engine braking.

 

 

 

 

Mine has the DSG box - I could have dropped it into N I guess, but in light of what happened I would rather not rely on the ABS

1 hour ago, PipH said:

In icy conditions there may be insufficient friction between the tyre & icy surface for the wheel to start rotating quickly enough, it may take a few seconds.

The ABS system then assumes there is a fault so disables itself.

 

That seems a sensible idea. The faults that occurred are also symptomatic of an ABS wheel speed sensor that has gone kaput and what you describe would mimic that.