2001 XC70 Tailgate Sensor

strueblood · Post by **strueblood** » 02 Nov 2009, 13:07

The sensor that indicates my tailgate is open is shorting - indicating the tailgate is open when it's closed, latched & locked. Occasionally when I go over a bump the warning light and error message will go away only to return a few seconds later. Also, it will occasionally trigger the the entry alarm while the car is parked and will unlock and lock all doors at will. My neighbors are tire of the alarm going off in the middle of the night!

Doug S · Post by **Doug S** » 03 Nov 2009, 07:57

This problem is most likely due to broken wires in the left hinge area of your tailgate. I had the same symptoms and found about 6 wires within the tailgate wire harness broken from continuous flexing over time. There is a little micro switch in the tail gate lock that closes when the tailgate is shut and provides a path to ground. If the wire is broken the grounded wire becomes open and you'll see the tailgate open message.

One thing I also noticed with my car is the rear license plate lights would go on and off as I opened and closed the tailgate due to the broken wires. You could look for this and the tailgate open message as you open and close your tailgate. The broken wires connect and separate within the harness while being flexed.

mister_merl · Post by **mister_merl** » 14 Nov 2009, 12:48

I also have this problem with my 2001 V70 (not a XC though).
What exactly did you all remove in order to get to the wire harness?
Just the plastic molding in the rear driver-side corner? If so, how do you take that off without breaking any plastic pieces?

strueblood · Post by **strueblood** » 17 Nov 2009, 17:17

I took off the black plasic piece on the left hinge and the wires were all okay. I then took off the inside door panel, which comes off with a star screw driver and 4 screws and then just pull firmly and the clips will let go.

I checked the wires all the way to the tailgate lock and they seemed fine as well. My guess is the contacts in the lock mechanism are corroded or something.

I took out the owner's manual and found the fuse for the security alarm and pulled that. The neighbors are all happy, no more random siren noise in the middle of the night. The flashers still blink when the alarm goes off, but no noise!

Next try is to replace the lock mechanism...

Doug S · Post by **Doug S** » 17 Nov 2009, 20:21

I also just read on another forum a connector to the rear window glass breakage sensor wire (defroster wire?) had come loose from slamming the tailgate and caused the open tailgate message. The rear window wire is part of the tailgate lock circuit. My car doesn't appear to have this connector so I don't know if all models/years have this as part of the lock circuit but it's worth checking.

strueblood · Post by **strueblood** » 18 Nov 2009, 19:51

What other forum? Does anyone know where the window glass breakage sensor is located on the window?