Remote Central locking faulty

Scott33b

Junior Member
Messages
52
Hi folks. Anyone got an idea why the key won’t lock remotely and arm the alarm?
Can Locks both doors and central locking using the key in the locks. I’m assuming it’s an alarm issue. Changed battery in key, but no luck. Where do I start to fault find? Any advice appreciated.
Cheers
 

CatmanV2

Member
Messages
48,557
First step would be a battery reset.

The fobs can go out of sync. If you stand close to the car and double click the lock button it might start working again.

If I'm understanding this correctly the remote fobs are not locking the doors or arm the alarm. If that's the case, given they are different systems I suspect it'll need a proper diagnosis by someone who knows how the interact. My limited understanding is that it would be a body computer issue, or I could be totally wrong.

C
 

Scott33b

Junior Member
Messages
52
First step would be a battery reset.

The fobs can go out of sync. If you stand close to the car and double click the lock button it might start working again.

If I'm understanding this correctly the remote fobs are not locking the doors or arm the alarm. If that's the case, given they are different systems I suspect it'll need a proper diagnosis by someone who knows how the interact. My limited understanding is that it would be a body computer issue, or I could be totally wrong.

C
Thanks. That’s what is happening, my guess would be an alarm ecu but not sure where to start.
 

CatmanV2

Member
Messages
48,557
Thanks. That’s what is happening, my guess would be an alarm ecu but not sure where to start.

So try the battery reset. Then the fob sync.

From there, unless someone knows how the two systems interact, I suspect you'll just be firing the parts cannon at it
C
 

Rex B

Member
Messages
657
If you have replaced the key batteries and tried both keys then l would suspect the central locking ecu which according to the diagram is responsible for send a signal to the window control unit which controls the windows and doors locks. There is a 25amp fuse in the footwell fuse box which powers the central locking ecu this could be the cause and worth checking.
Rex B
 

CatmanV2

Member
Messages
48,557
If you have replaced the key batteries and tried both keys then l would suspect the central locking ecu which according to the diagram is responsible for send a signal to the window control unit which controls the windows and doors locks. There is a 25amp fuse in the footwell fuse box which powers the central locking ecu this could be the cause and worth checking.
Rex B

Does the diagram show where the alarm get its signal to arm from?

C
 

Rex B

Member
Messages
657
The Central locking control unit, Door control unit and Alarm control units are all interlinked and without knowing what happens inside the units its not possible for me to be 100% sure. My guess would be that the Key fob sends a signal to the locking control unit which then interfaces with the window control unit which locks the doors and send a signal to the alarm control unit to set the alarm. But it could be the reverse of this and the alarm unit receives the signal from the key.
This is where a good indie with the Maserati tester is useful could save hours of wasted time and money, even if you only ask for diagnostics.

Rex B
 

Scott33b

Junior Member
Messages
52
Thanks guys. That maybe the way forward.
I’m back on the window issue again. Broken teeth again. Going to bite the bullet and get an Alfa one to modify
 

sparkplug155

Member
Messages
126
My alarm and locking would only work if I stood against the car. I found the aerial wire broken on the alarm unit so I am guessing that unit gets the signal from the key button.