Door lock problem - one door unlocks

[staffann]

I hope you all forgive that I ask a question about my -01 S60, but it should be relevant also to XC70s:

When I lock the car using the remote, sometimes the driver or passanger door immediatly unlocks again. What happens is that first the knob on all doors go to locked position and then on (or occationally two) front door knob goes up again as the door is unlocked. I have to unlock and lock the car until all doors stay locked.

Anyone had this problem and can give me a clue to what is going on? Is it a known problem? What to do about it?

If I wait half a minutes after I try to lock the car, there is a click from all doors and after that it isn't possible to open any door - not even the one with the knob in unlocked position. But although that helps a little bit, the time before that happens is long enough for someone to open the door and steal things from inside.

[JRL]

Sometimes it's a bad lock/actuator
and sometimes it's in the software,( or both)!
For this one you really need to see your dealer (unfortunately).
These work thru the car's computer so you need a Volvo dealer (or an independant shop who has VIDA)

[Aviator]

Try this....(1) Open all the doors. (2) Using your remote, lock all the doors with one press of the lock button. (3) Close all of the doors. (4) Double tap the unlock button on the remote to unlock all of the doors. (5) Lock all of the doors using the remote. The doors should all unlock and lock correctly from now on. This worked for me when the LR door didn't always lock. When I would open that door to lock it manually, the alarm siren would go off. I never did find out why that one door wouldn't lock with all the others but this method worked. I don't know why this worked either !! I wouldn't suspect any of the actuators as they obviously work.

Dave.

[Aviator]

Just an afterthought I had while driving this afternoon....sometimes the doors like to stick to the door seals which you see surrounding the door openings when you open the doors. It fooled me the first time it happened.

Dave.

[staffann]

Thanks for your answers. I'll try the procedure described by Aviator and hope for a miracle. Otherwise I'll have to visit the Volvo delar - something I don't like to do since they are expensive and I have bad experience of their work quality.

What is strange is that when I read the fault codes there was a code for the rear left door, but I've never had a problem with that door (although the DTC and freeze frame sais I do).

Tester -> CEM_HS: 50 AE 1B/ AE-Read DTC/1B-Request 2 byte DTC with counter 1, 3-7
Complete Response: EE 1B 6A 01 00 01 04 00 00 85 13 D7 B6 00 09 2F 00 00 02

6A01 Locked stucked in the unlock position or open circuit for the left rear door
Counter 1 1 driving cycle without fault (since last fault detection)
Counter 3 1 024 driving cycle in total (since DTC was set)
Counter 4 133 driving cycle with fault (since DTC was set)
Counter 5 1 300 406 seconds of ECU operating (since DTC was set)
Counter 6 2 351 seconds, possible to detect the fault (since DTC was set)
Counter 7 2 seconds of detected fault (since DTC was set)

6A01 Locked stucked in the unlock position or open circuit for the left rear door
RI: 6A06 LOCK-STATE Drivers door
LOCK-STATE Drivers door Door locked
LOCK-STATE Passengers door Door locked
LOCK-STATE Left rear door Unlocked
LOCK-STATE Right rear door Locked

I then cleared all DTCs and proceeded to lock and unlock the car a number of times. The problem appeared frequently on the front passanger door, but no DTC emerged. When I read the info about the locking status from the diagnostics, the car did however very well know that one door wasn't locked:

Tester -> CEM: 40 A6 6A 06 01/ A6-Read Current Data By Identifier/6A06-LOCK-STATE Drivers door/01-Send the record once
Complete Response: E6 6A 06 8B
LOCK-STATE Drivers door Door locked
LOCK-STATE Passengers door Door unlocked
LOCK-STATE Left rear door Locked
LOCK-STATE Right rear door Locked

I have access to a diagnostic tool from work (not VADIS or VIDA), which is how I read the diagnostic info.

[staffann]

Aviator: I', afraid the suggested sequence wasn't possible since the doors wont lock when they are open (step 2).

[geo]

This usually happens when one of he doors (including fuel filler flap and hood/bonnet) does not realise it is closed. maybe as above the sensors are oversensitive.
go round slam them all and start again. Sometimes it will not unlock at all, use the key, then very quickly turn on the ignition to shut up the alarm. Then again go round and slam the doors. Has always worked on mine so far for the few tmes it has done it.
geo

[Aviator]

Hmmm.....thought it might work for you. Mine will lock using the remote, but not with the lock switch in the driver's door switch array until you close the driver's door. Try cycling the door locks with the key in the driver's door lock, then try it all with your other remote.....could be a software difference.

Dave.

[tkirwan]

I must have a self-repairing Volvo. My '02 XC70 had this problem then it went away. It came back a couple of times for a visit shortly after it went away, but it hasn't shown this problem for several months now. Maybe it's temperature-related and I'll have problems again next winter?

[slowflyer]

Since nobody else has mentioned it, there was a recall on the '01 remotes. Mine kept unlocking all the doors after I locked them. Dealer fixed it no problem. Your problem might be covered.