The other morning something rather peculiar happened.

When I pressed the start engine button a whole host of error messages spewed across the dashboard,such as (but not limited to)

gear box fault
dynamic stability not available
terrain response not available
cruise control not available
HDC not available
Forward alert not available

There were several others but can't remember...but you get the gist.

So after a minor heart attack that every system on my car had simultaneously over night decided to commit suicide like some obscure religious cult, I powered the ignition off and tried again. This time the car started normally but one message remained and still remains today. "Forward Alert not available"

Sure enough when I try to adjust the F/A range - nothing happens and of course it doesn't given any beeping warning if I get too close to braking traffic ahead.

What confuses me though is that the adaptive cruise control still works perfectly fine. I'm sure the forward alert/adaptive cruise control used the same radar emitter/receiver(s), so they can't have failed.

Any idea what else might still be causing the "forward alert" problem and message to appear?

Thanks

a glitch because of a low powered battery.. ... - .- -.




Y. O. L. O.
.

+1 for above, battery on the way out  SDV8 AB MY 2019
SDV8 VSE MY 2015 - Gone
5.0 S/C AB MY 2010 - Gone
4.2 S/C VSE MY 2006 - Gone

practically a brand new battery and the car had just done a 150 mile run the night before. so battery should be in good order.

I ran a whole thread previously about park heating. One of the "fixes" LR did was to put a higher capacity battery on.

Normally I would agree with a goosed battery as it has random effect on the car but why would the Forward Alert message now remain consistently on? I would expect the "randomness" to continue

Last edited by Fleagle_UK on 23rd Nov 2015 5:20pm. Edited 1 time in total

i think its a typical FF problem where if the battery is a bit low [for what ever reason] when you start up some of the ecu's dont get their full power allocation so that particular ecu function wont work properly..
the best example is the lcd screen and radio controls.

see what its like tomorrow and hopefully it'll be back to normal.. ... - .- -.




Y. O. L. O.
.

I had a similar issue (spurious messages, not F/W Alert as that wasn't on earlier models) on my previous 2006 S/C and it was caused by a loose battery connection, so worth checking if it has only recently been replaced  SDV8 AB MY 2019
SDV8 VSE MY 2015 - Gone
5.0 S/C AB MY 2010 - Gone
4.2 S/C VSE MY 2006 - Gone

all connections (visible) all seem solid and tight.

message still consistent - all other systems in car are fine inc radio/display.

Is there anything I can do to reset the diagnostics?

dont know re the diagnostics but a hard battery reset might work.. ... - .- -.




Y. O. L. O.
.

I don't know about the L322 system, but my Jag XK8 had the Forward Alert system that packed up. It turned out to be the brake switch. Once a new one was fitted, all was well. Like I say though, not sure if the L322 works in a similar way, but perhaps worth keeping in mind.

Ian

yep - tried again this morning, still getting the same warning msg. Something more related to the forward alerts system me thinks rather than battery. (though with these cars I stand to hang my head in shame

Is a hard battery reset what I think it is ? i.e. disconnect battery and leave for an hour or so before reconnecting ?

I'll check the brake switch - but I assume it is ok as the brake lights work fine - I assume there is only one brake switch that just sends a on/off signal to any ECU of any system that may want to know the state/position of the pedal.

Does anyone know where the radar emitter is physically located? I just wondered if I could check to see if anything obvious e.g. loose connection/leaves/mud blocking them (don't worry I realise leaves shouldn't really interfere with radio waves that much...but hey, if they can bring intercity trains to a halt if fallen on the lines??..... )

thanks.

Disconnected the car battery and reconnected an hour later - no joy warning - message still shows on dash.

anyone any ideas ?

thanks
Neil.

To do a hard reset you need to short the terminals together for a few minutes (obviously not with the battery connected!).  Visiting from DISCO3.CO.UK
Discovery 3 TDV6 Auto HSE Zambezi Silver

errr...

so if i understand correctly and at the risk at me sounding stupid, I disconnect both cables from battery. touch them together and then reconnect both back to battery ??

....or have i missed something.?

Yes, basically this drains the ECUs and gets them to start up from scratch. One thing I forgot to say - you need to have the ignition on too.  Visiting from DISCO3.CO.UK
Discovery 3 TDV6 Auto HSE Zambezi Silver

errrrr....

how can the ignition be on if the battery is disconnected? (mine is a push button start)