Thread: Door unlocking question

Hi Alan,


I have had this issue once before and I had to change the car Battery. I don't know if this is the case with yours.


I would suggest that you get the car battery checked, as overnight is not a long period.


Regards
BKH

Thanks for the feedback BKH, I think the main car battery is fine because the car starts no problem and the remote works immediately after I unlock with the key. Let me go back one step - is it normal for Disco 2 remote to not work if the car is parked overnight or is this unusual?

Let me go back one step - is it normal for Disco 2 remote to not work if the car is parked overnight or is this unusual?

Unusual.
Have you tried a new battery in the remote?
They don't work for a long distance either .

Regards Philip A

I had a similar problem with my can not unlocking unless I was really close sometimes, turns out it was the car battery. The car was still starting strong, then one day I got it and it would hardly crank.
I replaced the battery and my unlocking woes went away also.

I recently had to replace main battery in my td5, and this was not one of the symptoms, so I think it's unusual.

You could try leaving the car on a trickle charger overnight to confirm if the problem is time related or battery voltage related.

Maybe just bad earth to the relevant module so the voltage it sees is too low, even though plenty available for starting.

Sent from my GT-I9100 using AULRO mobile app

By the way, I was glad to get hold of a nanocom and be rid of the two stage unlocking. The number of times I went to the swing gate and it was locked drove me nuts..... You can also check and adjust some immobiliser settings in there which may have been corrupt as part of your ecu replacement?

Sent from my GT-I9100 using AULRO mobile app

It's not very common but not uncommon either, there was a TSB for NAS specs on that but it's not public anymore ( LAND ROVER DISCOVERY II Bulletin - Vehicle TSB ID 102289 ), the gist is that the BCU has an internal timer which should put it in sleep mode after 72 hours, by turning the key in the lock wakes up the BCU and it works again... i've seen this not once that this timer gets mixed up by various reasons especially current shocks like welding on the body/chassis without disconnecting the battery or the BCU, alternator rectifier failures the AC gets into the circuit etc then the time untill the BCU ''goes to sleep" can get much shorter, the fact is that it's not fixable only by replaceing the BCU... untill then set the alarm in BCU on "always disarm with key" to be on the safe side.

It's not very common but not uncommon either, there was a TSB for NAS specs on that but it's not public anymore ( LAND ROVER DISCOVERY II Bulletin - Vehicle TSB ID 102289 ), the gist is that the BCU has an internal timer which should put it in sleep mode after 72 hours, by turning the key in the lock wakes up the BCU and it works again... i've seen this not once that this timer gets mixed up by various reasons especially current shocks like welding on the body/chassis without disconnecting the battery or the BCU, alternator rectifier failures the AC gets into the circuit etc then the time untill the BCU ''goes to sleep" can get much shorter, the fact is that it's not fixable only by replaceing the BCU... untill then set the alarm in BCU on "always disarm with key" to be on the safe side.[/QUOTE]



Thanks. This seems to fit the symptoms. The Owner's Handbook does indicate that the handset may not work after the vehicle has been parked for a 'long period', and your comment about the BCU being programmed to switching into sleep mode after 72 hours is consistent with that.


Regarding other suggestions, I don't think the handset is the culprit because I have 3 and all fail to work overnight (and work fine before that). The suggestion of checking that it is not an early indication of a battery on the way out by putting it on a trickle charger is a good one. Will do so tonight.


If it does turn out to be the BCU, is the fix simply a matter of switch the old unit for a new one, or is there more to it - eg reprogramming it and, if so, is that difficult? I'm still new to this vehicle and still getting my head around a lot of stuff.