Fob intermittently working

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Philso
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Joined: 01 Apr 2023, 13:49

Fob intermittently working

Post by Philso »

Hi. I have a 2015 citroen relay van. My fob works intermittently. I have changed the battery but it's made no difference. Atm it's not working. I can open the drivers door with the key but the central locking doesn't work & the alarm goes off. I've only owned the van for 3 months & was all good at first. Any help would be gratefully received
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GiveMeABreak
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Re: Fob intermittently working

Post by GiveMeABreak »

You probably need to reinitialise the fobs after changing the battery.

Generally, put the key with fob in the ignition, turn on the ignition only, press one of the lock buttons on the fob for a few seconds, switch off the ignition (do not attempt to start the vehicle), repeat with the spare fob too, then get out the vehicle, lock with the fob and unlock a few times, get in and attempt to start.

Be wary if you have attempted this too many times previously, it will go into anti scanning mode, so wait for 5 minutes before attempting the procedure above.

This is all part of the BSI Reset / Battery Disconnect / Reconnect Procedure which you should note for future reference.
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Philso
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Re: Fob intermittently working

Post by Philso »

Thanks for the reply Marc. I've changed the battery before & it's still been intermittent. It's just worked & has stopped working again.
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GiveMeABreak
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Re: Fob intermittently working

Post by GiveMeABreak »

Have you checked / replaced the batteries in the fob? This can have the same affect. Failing that, possibly a faulty transponder ring in the ignition. Do you have your VIN so I can see what system you have? (please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff).
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ozvtr
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Re: Fob intermittently working

Post by ozvtr »

If it locks every time but unlock is intermittent, it's probably the little switch on the transmitter PCB.
Philso
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Re: Fob intermittently working

Post by Philso »

Yes I've replaced the battery. Here's the vin number
VF7**************[VIN obfuscated, can be read by forum staff]
Philso
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Re: Fob intermittently working

Post by Philso »

The fob either fully works or it doesn't do anything.
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GiveMeABreak
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Re: Fob intermittently working

Post by GiveMeABreak »

Note that if 10 locking and unlocking operations are carried out within the space of 25 seconds, the system deactivates these controls for 30 seconds, so be aware of this when testing.

Also on this vehicle the resynchronisation is carried out by pressing any button on the remote control twice (this operation may be necessary after replacing the remote control battery).

There's also a locking control unit on this vehicle which handles the locking (although still controlled by the BSI), so it may be possible this has gone faulty, but if you've checked the basic things, then will need a diagnostic to check for faults before replacing:
relay lock unit.PNG
(1) door locking unit.
"a" Connector.
The door locking unit contains 4 relays which handle the following functions (according to model):
  • Relay 1: Front doors locking/unlocking relay
  • Relay 2: Common relay
  • Relay 3: Deadlocking relay
  • Relay 4: Rear doors locking/unlocking relay
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Philso
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Re: Fob intermittently working

Post by Philso »

Thanks Marc. I have 1 key fob & the master key. When the fob doesn't work & I open the drivers door with the key the alarm goes off if I don't turn the key twice. The central locking doesn't work with the key. I've just put the key in the ignition & turned it a little & pressed 2 buttons. After a few seconds the lock light went off on
my dashboard & my fob worked.
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GiveMeABreak
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Re: Fob intermittently working

Post by GiveMeABreak »

Fingers crossed that's all you needed to do.
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Marc