I was just out to walk the dog and when i returned my key doesn't work. The car was left unlocked and it just says "smartkey not detected". None of the buttons on the key would work either.

I took the key battery out and put it back in and it still didn't work so I had to resort to waving the key around the vague area of the NFC receivers to get it started. When it did start it then gave a parking brake fault which I was able to clear using the calibration procedure.

When i got home I got another parking brake fault after i stopped which again I was able to clear but I still couldn't lock the car. i assumed it was the key so got my spare from inside but that doens't work at all either

Is this a common/known issue? is the parking brake fault related? no other warnings are displayed. It has never done this before.

Try a new battery in the key fob sounds like the spare needs a new one too? sometimes my smartkey "cannot be found" all I do then is press lock or unlock button, and all is good, how old is the car battery could cause issues if old and down on charge. 2013 FL2 XS.
Defender 90 300 TDi.
Defender 90 300 TDi CSW.
1964 MGB Roadster.
1944 Willys MB "Jeep" with bullet holes. (gone)
17 hand Irish Drought Thoroughbred (mostly lame)
Nagging Old Boiler.

The battery in the fob is only 6 months old as I replaced it when it warned it was low. I also swapped the covers on both keys at the same time and tested both of them so I am resonably confident it is not a fob battery issue.

The car battery is original and healthy. I had it sitting in the garage for the last 3 months while I was changing the clutch/flywheel/PTU and when I put a battery conditioner on it it only needed 10 minutes to top up the battery and the start/stop works just fine (usually the first to stop working if the battery is anything other than perfect).

The car was fully assembled and back on the road last Sunday and I have done 100 miles since then with no other issues.

Edited to add: Just tried a new fob battery and it hasn't made a difference. From doing some research it sounds like it could be the receiver module or the the KVM. Going to check both of them out when I can.

"The car battery is original and healthy."

At 10 years old that has got to be a FL2 record  Jules

Jules, I am as surprised as you are. I have prepared to buy a new battery for ages but I just haven't needed to.

Ok, so I have just been out to have another look. pulled the KVM fuse for a minute. Disconnected the battery etc and no change.

I am 99% certain the issue is with the RF receiver (part LR143239) for the key as none of the functions on either fob work including the headlights and hazards. the problem is I can't find it. I had a look under the interior light and under the movement sensors and it isn't there. Can anyone point me in the right direction of where this is located?

In roof between rear doors (Item 5)

( I also am very surprised about age of 12v Battery )

 FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 76k+ miles) (MY2015)

I thought the NFC element of the keyfob (which operates the immobiliser) is independent of the battery and is a passive circuit with no power needed.

The battery and RF receiver are used for remote operations like locking/unlocking/panic mode only.

That and the mystery parking brake fault suggests the fault's in one of the on-car modules somewhere rather than the keyfob. It does rather sound like some of the weirdness you can get when the main car battery is getting weak, but you sound convinced that isn't the issue.

jules wrote:

"The car battery is original and healthy."

At 10 years old that has got to be a FL2 record

Occasionally my key, either key, can't be found, I hold it under the steering column as per Handbook instructions & it works.

I have measured the voltage of the button cell & it appears anything under 3.0 volts is an issue.

Just because you put a new battery in it doesn't actually mean it is any good. I got caught twice on tired new batteries. So check them with your multimeter. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

Am I right in thinking that the parking light on for no apparent reason means you have a Instrument Cluster Fault.
It's only connection to the Parking Brake Control Module is via the CAN link. FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 76k+ miles) (MY2015)

Last edited by IanMetro on 21st Feb 2023 5:59 pm. Edited 1 time in total

Rommel wrote:

Try a new battery in the key fob sounds like the spare needs a new one too? sometimes my smartkey "cannot be found" all I do then is press lock or unlock button, and all is good, how old is the car battery could cause issues if old and down on charge.

Just to update you all. Loaded the car up on Saturday to take some stuff to the dump. Keyfob wasn't working when I unlocked the car. While loading up i deliberately thumped the Rear interior light. When I went to start the car 10 mintues later the keyless start worked and the keyfob now works as normal!

The Parking brake fault did not re-occur at all and has been fine ever since. Only other electrical oddity to report is the ABS/TCS computer threw a fault while offroad but that was due to a wheel speed sensor after hitting a pothole. I cleared the code and carried on, but otherwise it has been fine.

Found this video.

Its not a late model FL2, but it should be similar.

You will see that he demonstrates starting with only the Near Field electronics left connected, although annoyingly he doesn't know how or where the car NFC works. I cannot find it (so far) in any documentation.



Notes
The Handbrake Control Module is very near KVM, so may share earths and/or power connections.

The Keyless Vehicle Module is on page 93 of my copy of 2013 FL2 Wiring Diagrams, can't seem to find a link that now works to download a readable copy ---- Perhaps someone can provide one.

The KVM is connected to several Aerial Modules in various parts of the car. It's KVM earth point G4D149 is located near the boot left hand wall area.

I think that the Near Field Receiver is on page 107 of the 2013 wiring diagrams, Module (T203) connected to the KVM via a single wire that sends serial signals. The clue to its location is the earthing point G6D139 which is below the steering column.

Still no write-up found.

I will continue looking as and when I have time. FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 76k+ miles) (MY2015)

Thanks for that IanMetro. I found the same video and found it quite usefull (that's why I started looking for the antenna under the front interior light.

I do have a leaky 3rd brake light and my AC is brken so it wouldn't surprise me if the issue was due to moisture.

touch wood it is behaving itself now.