'05 S80 trunk release issue

DanK · Post by **DanK** » 09 Mar 2014, 06:48

Hello all. I am puzzled. The trunk latch above the license plate does not work. I hit the trunk release button on the FOB twice and the trunk releases...so that works. Now the puzzling part. When I open my driver's door, the trunk releases. I would then have to close the trunk. Also, occassionally the trunk will release will driving. Seems like an wiring issue. Any advice on where to start? Thanks.

Post by **precopster** » 09 Mar 2014, 12:03

Disconnect and reconnect battery while key is in POSII before looking for gremlins. This allows the rear module to restart and hopefully reset to proper operation.

DanK · Post by **DanK** » 09 Mar 2014, 13:45

Hi precopster...did not work. I may have to start looking for gremlins.

Post by **VCA** » 09 Mar 2014, 20:17

You're probably not going to like this, but I'm suspecting an internal fault in the REM. Inspect wiring harnesses in the vicinity of the REM for broken insulation, but if you don't find any, and manually shorting pins F:3 and F:5 doesn't release the trunk, the REM is probably the culprit. I've attached the central locking wiring diagram.

Skaytex · Post by **Skaytex** » 13 Mar 2020, 12:19

I have the same problem. Did anyone solve this problem?

Post by **precopster** » 14 Mar 2020, 00:02

Yes I solved it on our '06 XC90 by testing the REM with Vida/Dice first. In Activations there are trunk lock and release commands to establish if the pulse is going to the lock/unlock motor.

On ours I could only audibly hear the lock pulse at the motor. As the same wiring for lock is used for unlock (REM merely reverses polarity to the unlock motor to have it wind backwards to unlock) it was obvious the REM was faulty. I was lucky enough to find an REM with compatible software without the need for a dealer (or Doublebug) reload.

Skaytex · Post by **Skaytex** » 14 Mar 2020, 13:52

precopster wrote: ↑14 Mar 2020, 00:02 Yes I solved it on our '06 XC90 by testing the REM with Vida/Dice first. In Activations there are trunk lock and release commands to establish if the pulse is going to the lock/unlock motor.

On ours I could only audibly hear the lock pulse at the motor. As the same wiring for lock is used for unlock (REM merely reverses polarity to the unlock motor to have it wind backwards to unlock) it was obvious the REM was faulty. I was lucky enough to find an REM with compatible software without the need for a dealer (or Doublebug) reload.

Hi, do you know how to find software version?

Post by **oragex** » 21 Mar 2020, 17:41

I had this issue, the trunk would release if I tapped on it and the lid button would not work but the fob button would. First, make sure there is no light on the center console button with a pictogram of a trunk lid with a key. Then, undo the lid cover and push into the wires at all connectors there - about 3 of them. May also undo and replug each one. Tap on the trunk lock as well a little. Then may want to verify continuity at the lid harness as shown here www.youtube.com/watch?v=O1ruROdlZkk