P38A Alarm Fault when inserting ignition key

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pwood999

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Started getting the Alarm Fault message quite regularly. Based on various threads, I cleaned up the ultrasonic sensor connections, and also lubricated ignition barrel with graphite powder. Fault went away for two days, but now back again.

Need to double check all door latch switches tomorrow, but what else could be causing this ? Nanocom doesn't have option for Alarm or BECM fault codes.
 
Started getting the Alarm Fault message quite regularly. Based on various threads, I cleaned up the ultrasonic sensor connections, and also lubricated ignition barrel with graphite powder. Fault went away for two days, but now back again.

Need to double check all door latch switches tomorrow, but what else could be causing this ? Nanocom doesn't have option for Alarm or BECM codes.
There are no BECM fault codes. I think the ultra sonic sensors are only active when super locked. What year is the car and is the BBus alarm fitted?
 
Barrel switch seems to be ok. Nanocom shows it toggle when inserting & removing the key.

All doors lock & unlock correctly with fob or key, but need to verify they actually change lock status correctly.
 
Checked all the BECM inputs with Nanocom earlier.
  • All doors lock & unlock correctly using FOB, and flip from 12V to Ground in the Nano screens.
  • Bonnet & Tailgate correctly show closed.
Strangely after connecting Nanocom & testing the stuff above, the alarm Fault message has gone away. Tried locking & unlocking both manually & with Fob, but fault no longer there. Bet it comes back later though :eek:

Shame the BECM menu in Nano doesn't have more details.
 
Checked all the BECM inputs with Nanocom earlier.
  • All doors lock & unlock correctly using FOB, and flip from 12V to Ground in the Nano screens.
  • Bonnet & Tailgate correctly show closed.
Strangely after connecting Nanocom & testing the stuff above, the alarm Fault message has gone away. Tried locking & unlocking both manually & with Fob, but fault no longer there. Bet it comes back later though :eek:

Shame the BECM menu in Nano doesn't have more details.
Wet carpet and underlay in the drivers footwell?
 
Yes good idea. My plan is to take seat out & check the Kick Panel & BECM connections. Left footwell connections were soldered years ago, but never got around to doing right pair.
 
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