2001 V70 Xc Car locks itself. Wiring or Module? Topic is solved

[daughtersmechanic]

Daughter's 2001 XC70 (which I have begun calling The Beast) will occasionally lock her out of its own volition. No amount of key-twisting will get it to respond, and there is no fob. I took the driver's side door panel off, hoping to find a loose or broken wire. What I found were two pairs of wires, each electric-taped together with a single wire coming out and completing the journey to the plug.

DoorWiresWithArrows.PNG

It looks like the Green wire is spliced on to the Purple/White wire, which goes to the plug. The other pair is Blue and Blue/White. Can anyone tell me if that is how this is supposed to look? I am, of course, looking for a cheap & easy fix; not looking forward to tracking down a used or rebuilt door module, but also not wanting to unwrap a factory connection if I don't have to.

I'm open to any suggestions.

[MoVolvos]

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I would remove the electrical tape first to see if there is a good connection. If it is only intermittent the splice maybe OK just not connecting well.

[daughtersmechanic]

I’m guessing some spliced in either a remote start or a fob into the factory system. You need to find a wiring diagram to proceed And cut that junk out. Based on the wiring workmanship, the lock Issues aren’t surprising

Be careful what you are doing, it’s easy to brick a 1999- on Volvo

[daughtersmechanic]

I’m guessing some spliced in either a remote start or a fob into the factory system. You need to find a wiring diagram to proceed And cut that junk out. Based on the wiring workmanship, the lock Issues aren’t surprising

Of course! I knew that couldn't have been factory standard, but had no clue what it might be. Next chance I get, I'm going hunting for a 3rd-party module with a green and a blue wire coming out of it (among others, I'm sure). Tracked down the wiring diagrams: I am not an electrical engineer, and these things make my head hurt, but the Blue/White & Violet/White wires appear to signal Unlock and Lock, respectively, making your guess that much more likely to be correct.

MoVolvos, you are much more courageous than I am! It may come down to merely disconnecting those wires, but I'm pretty cautious with automotive electronics.

Thank you both, for your input!

[daughtersmechanic]

So, I took a look under the dash, Didn't find any remote start or key fob modules, but I did find another pair of wires running up to the steering column. They were attached to a very thin wire that was wrapped, many times, around the ignition switch and held in place with electrical tape. I removed them, and the two wires attached to the door lock wires mentioned previously. Whoever installed them really loved their electrical tape and zip ties! While doing so, I noticed that there seemed to be several wires in the bundle running under the steering column that were wrapped with electrical tape. That does worry me.

Unfortunately, things are still not normal. The key will not lock or unlock the drivers door, and the door lock button on the driver's armrest doesn't function either. All the other buttons on the panel work, except for the right rear window. Also, when I push the lock pin on the driver's door, there is a click( well, more of a solenoid chunk sound), then the pin pops back up with another chunk, then back down, and all doors lock.

Am I looking at a new Drivers Door Module now, or is there another possibility of a crossed wire somewhere?

[daughtersmechanic]

That action, locking followed by unlocking is normal function for the Volvo locking system if it detects a door ajar. It could just be one of the lock signals isn’t getting to the lock control module

I though the driver door key opens the driver door mechanically, so if that isn’t working, you need to open up the door card and either replace or repair the door module. Junkyard probably best , They don’t fail often. I don’t think they’d need programming.

[daughtersmechanic]

OK, then that symptom is probably a result of my testing-- I opened the rear door just in case The Beast decided to lock me out. Will test the mechanical action after work today. I'm guessing that the inoperative buttons on the door panel still point to the DDM. It's been a long time since I rummaged through a junkyard. Gonna need to find where they are these days. Anyone have a favorite in the Mpls-St.Paul area?

[daughtersmechanic]

Will test the mechanical action after work today. I'm guessing that the inoperative buttons on the door panel still point to the DDM.

I think you should back up a little. Remove one at a time each splice and take a look at the connection. Nothing too hard at all. Solder if you feel the wires are not bound together well.

Let's say someone was all bandage up here and there all over the body from an accident. The person develops a fever and it's an infection according to the blood test. The prudent thing to do is check all the bandages first for infection instead of looking at the major organs. Poor analogy perhaps but your test results from something inoperative can't point to anything unless you check the obvious first.

[daughtersmechanic]

It's been a long time since I rummaged through a junkyard. Gonna need to find where they are these days. Anyone have a favorite in the Mpls-St.Paul area?

I have tried many of the scrapyards around here & have come up with almost nothing for P2 stuff. That being said, there is a place in Glencoe that advertises on CL & typically has a couple cars you can call & ask about.

I've had the best experiences with Strandberg Auto in Centuria WI. It's really not that far of a drive, and a nice one at that, whether you go through Stillwater, Osceola or Taylors Falls. Compile your list (and a list of parts you'll need in the future ie blower motors etc...) and give them a call ahead of time. If you are buying a lot of stuff they usually knock a few bucks off. I usually ask to talk to Kevin, but I've never had a bad experience with any of their other staff.

https://www.strandbergauto.com/

[chrism]

If your old DDM has a little white sticker with two or three numbers on it then you want to match those numbers to the sticker on the replacement DDM. I replaced mine a couple years ago with a junkyard part and as I recall I was able to match two of the three numbers. I also made sure the replacement came from the same year car. End result - it worked.