Random flash and lock

[Wolfywolf]

Hi all

Whilst looking out of the window with the car key on the table I have just noticed my 05 XC90 give a 'Locked' flash on the indicators, now I locked the car up about 5 hours ago so it cant be the deadlocks, this is the second time I have witnessed it, but my neighbour asked if I was trying to make him jump a couple of days ago as the car unlocked then immediately locked itself again.
Does anyone have any idea what is causing this to happen?

[reggit]

Surely it’s got to be one of the remote controls sending a signal to the car?

First place I’d be looking is to see if one of the remotes has a faulty micro switch or corrosion on the circuit board.

[gmonag]

Could be RF interference. Garage door openers, wireless doorbells, wireless burglar alarms etc. often work on the same frequency.

[reggit]

Originally Posted by gmonag

Could be RF interference. Garage door openers, wireless doorbells, wireless burglar alarms etc. often work on the same frequency.

The indeed to, but these would jam the remotes. For the car to respond it must have received the correct rolling code it was expecting or it wouldn't react.

[Clan]

Originally Posted by Wolfywolf

Hi all

Whilst looking out of the window with the car key on the table I have just noticed my 05 XC90 give a 'Locked' flash on the indicators, now I locked the car up about 5 hours ago so it cant be the deadlocks, this is the second time I have witnessed it, but my neighbour asked if I was trying to make him jump a couple of days ago as the car unlocked then immediately locked itself again.
Does anyone have any idea what is causing this to happen?

It could be the first sign of water in the CEM being a 2005 model year

[Wolfywolf]

Thanks for the input.

@reggit, I have looked at the remote fob and its clean, not only that it won't reach the car from where it is kept in the house (used to have a keyless merc so it's pretty much shielded in the box it sits in on the table).

@gmonag, Other than wireless doorbells there is not really very much around here that could cause any interference, the only thing I can place as a source would be an Amateur Radio operator in the next road.

@Clan, CEM? where is it located and I will have a check to see if it looks like there are any seals missing or perishing, there was quite a lot of standing water on the road last night.

[Clan]

Originally Posted by Wolfywolf

Thanks for the input.

@reggit, I have looked at the remote fob and its clean, not only that it won't reach the car from where it is kept in the house (used to have a keyless merc so it's pretty much shielded in the box it sits in on the table).

@gmonag, Other than wireless doorbells there is not really very much around here that could cause any interference, the only thing I can place as a source would be an Amateur Radio operator in the next road.

@Clan, CEM? where is it located and I will have a check to see if it looks like there are any seals missing or perishing, there was quite a lot of standing water on the road last night.

ahh thats a clue .. the CEM is the large black "fusebox"/ main computer above the throttle pedal under the dash . disconnect the battery , take off the plastic panel under the windscreen wipers , and the cover off the bulkhead where the wires go through and undo the 2 multi plugs from the top of the CEM . look for wet and corrosion on the pins .. If you find any it would be a good idea to get the CEM out , dismantle it so you can dry out the board inside and look for corrosion on the circuit board . when re fitting volvo do repair parts , new connector blocks and a modified water proofing kit for where the wires go through . If it has been leaking for a while it could need a new CEM .

[Wolfywolf]

@clan

Thanks, I will check it out as soon as I can.