Permanent Fault : Communication fault with Alarm ECU

Having issues with central locking and the boot switch not being energised. I have checked the actuators via lexia and the boot switch operates the mechanism thereby ope ning the boot. However there is a fault on the alarm ecu - Permanent Fault : Communication fault with Alarm ecu

additionally in the BSI configuration There is two alarm options Swiss alarm option and Belgian alar m option. The Belgian option is tagged present

where do i find the alarm ecu?

Any hints or tips would be gratefully received

northcoaster wrote:Having issues with central locking and the boot switch not being energised. I have checked the actuators via lexia and the boot switch operates the mechanism thereby ope ning the boot. However there is a fault on the alarm ecu - Permanent Fault : Communication fault with Alarm ecu

additionally in the BSI configuration There is two alarm options Swiss alarm option and belgian alarm option. The belgian option is tagged present

where do i find the alarm ecu ?

Any hints or tips would be gratefully received

Hi northcoaster

I think the Belgian and Swiss options are for local regions that have laws regarding alarm noise timing that differ from the general EU region.

It can be used in the UK to hide faults in the alarm/fix an annoying fault by effectively disabling some of the noise the car makes in some way.

As for the Alarm ECU, its located in the driver footwell.
To get your bearings, in the picture is the steering column and the clutch return spring that is part of the clutch pedal.


If you need to find the sounder, its in with the front wiper motor and wiper mechanism


This is my current configuration for a working alarm with volumetric sensors and deadlocking on an early C3

Hello C3car,
thanks very much for your reply and info. Invaluable ! I have located the alarm ecu plug.............the ecu unit is not there.
i will have the lexia back on tomorrow - so i hope to carryout further investigations

cheers

northcoaster wrote:Permanent Fault : Communication fault with Alarm ecu

northcoaster wrote:I have located the alarm ecu plug.............the ecu unit is not there.

Explains a lot


Hopefully it will just be a case of plugging in one of these Alarm ECUs from ebay (here) and off you go.

C3car,
If the Alarm ecu is not present would that impact the central locking ? (things take longer to deliver up here......... )
Via Diagnosis / C3 / bsi / activation then 'Locking'
I have - Locking of Locks - InActive
UnLocking of Locks - InActive
DeadLocking of Locks - InActive
Opening of Boot - InActive
However if I try opening any of the above I get - 'Operation not possible'

If I manually activate the commands ie opening of boot etc - everything works

When I have lexia connected on Diagnosis / C3 / bsi / Configuration

Guided Manual Configuration I see: ABL type of locking - (0x) - 0 0 (both zeros have an underscore)

Should this not have a value ?

Cheers

There is another possible location for the alarm ECU, if the alarm was fitted as an extra rather than factory fit, then the ECU would be behind the plastic trim panel at the end of the dash. Open the front door nearest the BSI (LH) and you will see the panel on the end of the dash.

The alarm is not required for central locking, although the alarm does work from the central locking remote when fitted. Not all models have an alarm as standard. It might be worth looking for the siren (located as C3CAR has shown above) and ultrasonic sensors to see if you have had an alarm and not just someone turning the setting on.