Hi all,

I wonder if anyone knows how the ISL is meant to function. The docs mention it uses TSR and Nav data to set the limit.

My experience is that it’s only the TSR that’s setting it, it doesn’t seem to care what road you’re on.

For example ISL is on. Driving down a 50mph A road quite happily and the camera sees a 20 sign on a side road and sets the limit to 20, immediately setting off an alarm and the car begins to slow.

Surely that’s the opposite of intelligent?!

Any views or experience pls?

(car is 2021 St-line x 125 mhev with Sync 3.4).

Yes mine occasionally thinks it's in a 20 when it isn't, perhaps because of your comment above which I hadn't thought of. It's repeatable at the same place so I will check for a side road sign next time I go along there. I don't often use the ISL unless there is a chance of many speed cameras along the route - like the A5 near Cannock!

Another annoyance is that it’s only ‘intelligent’ when a seen speed sign is registered on the dash. It’s dumb to what road you’re on if it hasn’t seen a sign.

Additionally it ‘times out’ after not seeing a sign for a while, disabling the speed limiter by itself completely.

This further leads me to believe it’s not using any form of navigation data.

17 minutes ago, Smartd00d said:

Additionally it ‘times out’ after not seeing a sign for a while, disabling the speed limiter by itself completely.

I don't have ISL but I do have TSR and mine does this too. It's completely illogical so I took the car to my Ford dealer who said they understood my point and did a software update.  No difference, and so between us we assumed that's just the way that Ford have designed it for some reason. They were sympathetic but essentially ended up saying "it's a feature, not a fault, sir".