RESOLVED 2001 XC70 Replaced Starter and Now Immobilized

Post by **deepsouth** » 15 Aug 2015, 18:37

Hey folks-
I've owned around four pre-99 Volvos and they were all fantastic. I've done timing belts, head gaskets, and many other difficult jobs on the pre-99's. That said, I'm about at my wits' end with my 2001 XC70.

I've had it for about three weeks. First three weeks no problem other than crappy radio reception and the cd/tape deck don't work. No big deal. Then Thursday happened. Went to a doctor's appointment and got in the car and it wouldn't start. Nothing. Not even a click. Had my girlfriend tap the starter while I turned the key and it fired right up. Assuming it was a starter issue I replaced the starter today. A bit of a pain in the ass as the ETM tube is difficult to reattach without removing the fan (it is possible though). Further, the replacement Duralast starter from AutoZone was a bit longer and the bracket mounting bolts were smaller. Again, no big deal--after a bit of modification I had the starter swapped.

After putting it all back together I'm having the same issue except this time tapping on the starter won't start the car and I'm getting an "Immobilizer, See Manual" message. I don't have a manual to this vehicle and also don't have the key fob. Only a single fraying rubber key. Now for the big question. What happened? I believe I definitely had a starter issue as the old starter wouldn't work without being tapped. But now I can't get the car to start at all and have no idea why it's been immobilized.

I'm starting to regret my decision to update models to 2000 and newer. Any help is seriously appreciated!

Eric

Post by **deepsouth** » 15 Aug 2015, 19:13

I should also add that before all of this happened my only message was "Alarm Service Required." Not sure if it's related.

Post by **precopster** » 16 Aug 2015, 03:49

It may be a coincidence that the tapping created a start condition because the Alarm Service Required message is usually a fried immobilizer board which sits behind the passenger side (if in USA) wheel liner. Lots of repair posts about this topic here.

The fix may be a simple soldering in of 2 X 3.6 V batteries onto the board to create the 7.2V required or if the battery acid has really done some damage it will be off to the pick and pull for another immobilser board.

Post by **vtl** » 16 Aug 2015, 07:03

Did you remove battery's negative lead before starting the work?

"No crank" in my case (and few other guys around the Volvo forums) was oxidized terminal on starter - had issue reoccurring even after a new starter was put in. Fixed by removing the small plug, cleaning everything thoroughly, and reattaching with use of dielectric grease. Car (2002 V70) starts with no issues for a few years since the repair.

"Alarm system service required" - http://www.volvoxc.com/forums/showthrea ... went-south

Post by **deepsouth** » 16 Aug 2015, 07:31

Yes, I removed the negative cable before all work.

I suppose it could be a coincidence that tapping the starter worked when it was really the alarm unit but it worked around 8 to 10 times.

I'm wondering how the immobilizer system works and why a (possible) bad connection (at the starter) would display the immobilizer message? I've checked out a few videos and don't have an issue pulling the fender skirt and soldering in a few batteries into the alarm box but don't want to do it yet if not necessary (I was planning on replacing the evaporator core on my 2000 S70 today but am now stuck with this instead

)

I've also read about the antennae ring going bad as well. Is there a test for this?

Post by **vtl** » 16 Aug 2015, 07:40

Taking out alarm siren will be much easier if you drop the bumper and remove passenger side headlight. In this case you don't need to drill rivets and work on hidden screw in a very tight space. My XC70 had this screw frozen, I ended up dremelling it out after 1.5 hours of "joy". V70 was easier. But, anyways, I wish I had read the advise of how to get access to siren through the headlight. Also while the bumper is off, it's a good occasion to install aftermarket transmission cooler and Magnefine filter.

Used antenna ring is about $30 on ebay.

I would buy DiCE and read the codes. Or find one to borrow.

Post by **deepsouth** » 16 Aug 2015, 07:55

Thanks for the info. I was just looking at the XC fender trim and wondering about the removal. So if I pull the bumper, and pull out he passenger headlight I access the siren/immobilizer box easier?

Also the antenna ring is just that--an antenna. It's not vehicle specific at all? I'm also going to pull the starter again and check all connections. It's odd because at least the old starter would work when tapped.

If I understand this correctly, the car will become completely immobilized because the batteries are either dead or have leaked onto the circuit board? (In which case the car won't start unless the unit is repaired?)

Post by **vtl** » 16 Aug 2015, 08:15

Access through headlight is much easier.

Antenna ring has Megamos Crypto chip in it, which gets plain messages from the car's computer and communicates with ID48 chip in the key through encrypted radio protocol. It's not vehicle specific module though. Sometimes it goes bad because of tin pest issues in eco-solder.

Alarm siren will not cause no-start condition, but it drains the main battery and often causes malfunction of roof window as it sits on the same LIN bus.

Post by **deepsouth** » 16 Aug 2015, 08:18

This appears to be a common problem. Is there a way to bypass the immobilizer completely?

And yes, interestingly enough, my sunroof is inoperable. (It worked last week).

Post by **deepsouth** » 16 Aug 2015, 09:02

Okay, pulled the bumper and the immobilizer and it was unplugged. Which makes no sense to me because it must have been unplugged for the past three weeks--and it's been running great. Which leads me to the question: can I just keep it unplugged? I plugged it back in and the "Alarm Service Required" message is now gone but still no start and "Immobilizer See Manual" message.

Any ideas are welcome! Thanks!