L322 keyfob signal not received

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kermit_rr

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Left the car for a couple of hours, came to unlock and non of the fob buttons work, I'd not had any "keyfob batt low" messages and the battery is less than a year old. Unfortunately there is no telltale on the fob to confirm function.
Opened the passenger door with the blade (why can't you open the drivers door!?) and obviously the alarm goes off. At this point, I wasn't sure exactly where to place the key for the passive action to de-arm the immobiliser and alarm so went home (managed to get a lift!!) for the spare key. This also wouldnt work, but having read the handbook managed to get the car started and home.
the keyfob needs to be placed just below the footwell light in the kick panel, just by your knee. the keyfob must be oriented with the buttons facing the floor and you must be very precise with the location. Rotating to keyfob appeared to assist. Do this while pressing and holding the start/stop button on the dash and it should fire up.
Note, the glovebox cannot be opened until the car is disarmed, so you can't check fuses! I checked fuse 1 and 17 in the glovebox but both are OK.

Diagnostic read gives the following codes;
B112C-87 - interior motion sensor
B1B01-87 key transponder
U201F-31 external receiver - type 31 - FM/PWM failure, no signal

not worried about the motion sensor right now and the car was not superlocked.
the key transponder code is related to pressing the start button when the car cannot see the fob, i did this.

the last code is the issue.

causes - comms to the module have been lost, check the keyless entry module circuit. check and install rf receiver or keyless entry module as required

I have previously had a medium canbus DTC U0010 (canbus failure) which may or may not be related - this DTC is not current.
 
well I've taken the time to write a detailed thread and the car is on best behaviour and 'fixed' itself
obviously i frightened it by parking the other way around on the drive.. it knows the garage door will open and sharp tools will come out!!

I have since read that removing fuse 17 from the glovebox can do a reset on the keyless module, maybe leaving it overnight does the same thing - something to consider and try the fuse if/when it happens again.

I've not checked for DTCs yet, so lets wee what happens
 
Well checked for DTC after doing a clear and seeming what comes back
I'll do another read tonight but something is not quite right.
At every turn, SDD asks me to confirm car options.. do i have rear climate seats.. do i have this.. that.. the other.. :(
 
Well i obviously jinxed it. Parked in the same spot.. got out and fob didn't work. Come straight back home and the other fob doesn't work either
 
It could be that the signal is being swamped by a nearby RF source, in which case disconnecting and reconnecting he battery will make no difference.
I did think that but it didn't work at home either. Disconnecting the battery for 30 min didn't help.
The error codes are quite clear that the car lost signal from the key module, not bad signal or no signal from the key
 
OK, so a dodgy module or damp.
could be.. i thought there was damp but a good hunt and nothing obvious and every connector i can find looks clean with no corrosion.
latest diag shows 'untested dtc' in the keyless module for 'lost communication with body control module (no longer reported)', 'Medium speed CAN communication bus.' and 'Communication to the RF receiver module has been lost. (current)'
 
the keyless module is responding because i can read error codes from it and the icon on the screen is an 'i' in a circle which means the car can see the module but its got an error code
 
I'm happy (ish) to accept it could be a faulty module. But surely they either die dead or they don't? It's worked fine for 2 weeks now.
It could be a corroded/damaged wire, but that would be more intermittent/regular?
It could be bad interference given i was parked in the same place (within a couple of spaces) but then why didn't it work when i got home?
And finally, why didn't a battery disconnect 'fix' it, but left overnight did?
Diag has a special function called 'vehicle reset' sounds exciting.. anyone know what that does?
Also an option to configure the keyless module, assume that's too add/remove keys.
On demand self test for keyless module.. that sounds interesting...
 
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