From the manual

"ACC not available - If the ACC is unavailable, a message concerning the unavailability appears. Stop the vehicle, switch off the engine and then start it again."

I am having to do this when I start the car in the morning, it always works when I restart the car. Anyone know what is happening? is it possible it will not fix itself in the future?

I can get while driving. Seems to be certain large object near the car cause it to get confused.

Regularly get it when driving through the northbound Blackwall tunnel.

It sorts itself out once I am out of the tunnel.

24 minutes ago, WayTooTall said:

I can get while driving. Seems to be certain large object near the car cause it to get confused.

Regularly get it when driving through the northbound Blackwall tunnel.

It sorts itself out once I am out of the tunnel.

Sounds like the radar isn't correctly aimed.

8 minutes ago, PetrolDave said:

Sounds like the radar isn't correctly aimed.

It has been recently calibrated and still get it.

 

It is large solid objects are close to the car, such as tunnel wall or sometimes those new concrete barriers on the motorway. Seems to cause it to get confused.

2 hours ago, WayTooTall said:

It has been recently calibrated and still get it.

 

It is large solid objects are close to the car, such as tunnel wall or sometimes those new concrete barriers on the motorway. Seems to cause it to get confused.

Sounds like the beam pattern is too wide (because of an internal fault maybe, has the radar been hit by anything?) causing it to detect objects beside the car and not just in front of the car.

1 minute ago, PetrolDave said:

Sounds like the beam pattern is too wide (because of an internal fault maybe, has the radar been hit by anything?) causing it to detect objects beside the car and not just in front of the car.

Given that is happens in very specific places, I think it is just an issue with the design of the Radar. The northbound Blackwall tunnel, the wall can be very close to the side of the car, and I suspect is causing some reflections. Doesn't happen in the southbound tunnel that is a bit wider.

The other place I used to get it, was in roadworks at the M5/M42 junction. Again this was the barrier being very close to the car.

The car has had the radar calibrated at least twice, and no issues found during the calibration. Once when the car was lowered, and once after an accident that took out most of the front left hand side of the car. The behavour of the radar hasn't change before or after the accident.

I've never had any problems with the ACC radar in the last 4 years that we've owned our Octavia.

 

The only time I've seen the "ACC not available" message is when I change the ASR/ESC setting away from normal to Off or Sport - which is expected behaviour.

Edited 27 January, 20206 yr by PetrolDave