Our '06 2.5t's warranty ran out in November and wouldnt you kow it, Dec. 1 we started having some odd electrical issues.

The first, tailgate open msg and rear light on even when tailgate completely closed. This might just be the tailgate lock needs replacing...

Next, alarm started going off when there was nothing that should have caused it. Happened 8 times over three days parked in three different locations.

That has stopped and we have not had any more of those but I thought I would include it as it might paint a bigger picture (or confuse the issue I guess...).

Now, just yesterday I went through a touchless car wash and since then every time I put it in reverse I get the backup alert alarm even when there is nothing behind for miles. Haven't tried it today but yesterday I tested it out 6 times over the span of 2 hours driving around town and every time the backup alert alarm went off when nothing was within 10 feet of the car.

Any advice greatly appreciated.

Thanks.

 

I can’t help with the backup alert alarm but here’s some information about the tailgate open message and car alarm going off.

https://volvoforums.com/forum/showth...e+open+message


Had same symptoms with my car last year, tailgate open message (when closed), random alarm trips, tailgate open message showing up while driving.

My problem was broken wires in left hinge area of tailgate. Constant flexing of wire breaks them in the tailgate wiring harness. I had about 6 broken wires, some wires completely broken but still touching (most of the time) in wire harness bundle. Depending on which wires are broken you may also see problems with the rear wiper motor, top brake light strip, rear window defroster or tailgate license plate lights.

There is also a micro switch in the tailgate latch that could potentially cause the tailgate open/alarm problem but I would first suspect broken wires, especially if you see any of the other tailgate related problems mentioned. Only one wire is associated with the tailgate open/alarm problem.

Alarm goes off because of open circuit to ground caused by broken tailgate wire or bad micro switch in tailgate latch. Alarm monitors all doors, hood and tailgate, if any are opened when alarm is activated then a switch opens the circuit to ground and alarm goes off. The broken tailgate wire or micro switch are causing an unwanted open circuit.

I've also read the tailgate is closed circuit also goes through a glass breakage sensor, which is a wire in the tailgate window and there are connectors that plug into this wire in the window and can come loose when the tailgate is slammed. My car does not have these connectors but yours may and I not sure if the connector is visible or under the tailgate interior panel. This would be another tailgate open circuit problem if the connectors come loose.