Once again - there is no "programming" or download needed when you replace an antenna ring.

 

Understood, thanks, But a) Volvo dealership here in France says there is and b) After replacing both the antenna ring and starter + solenoid, the problem persisted. As I've said though, as of yesterday, the car started fine both cold and hot (hot starting was the problem). Just a fluke? I don't know. I'll see again today.

 

Software is not going to be erratic. Either it's got the correct software or not.

 

I have to agree with you there and I don't know exactly what their thinking is. But they have repeated that what they call "recoding" (translated from the French) is needed and that in any case it's the necessary next step in the process. Am I convinced that it will make the problem go away? No. But I don't have much choice about it as the next thing to do. Scheduled for Monday. We'll see;;;;;

 

Does the problem happen if you use your other key?

 

Only one key I'm afraid. Wondering if it's the key itself or the ignition barrel? I have replaced the battery in the key fob.

 

Volvo's local agent here now recommends a new key, based on their conclusion that the transponder chip in our only key has become damaged in some way as to make it function only intermittently. They don't seem 100% sure though!

 

Sounds like they are gonna suck the money out of you .those transponders don't really go bad....

 

The OP only has one key. IMHO it’s always a good idea to have more than one key. A valet key(without a remote) would be hie least expensive choice.

 

I'd go out and buy a switch before I did anything else.i know these ignition switches can go bad when they get old.....

 

I'd test the switch when the problem was happening BEFORE purchasing any more parts that are not proven bad. I've replaced hundreds of Ignition switches - but all on earlier cars - and on those the accessory position malfunctions. I have never replaced a (140,240,850,960,svxc70,01+svxv60,xc90-14, etc ) ignition switch due to no signal from it in the start position

 

Yes that's a worry. However each of the steps taken so far has been suggested on this site and none has yet worked. (Fuse, relay, antenna ring, starter). The Volvo concessionary's mechanic in Agen, France showed me the output from his diagnostic and it recommends a new key. But frankly he didn't seem 100% convinced. I should know more on Friday.

 

Yes you're right about only having one key. Your idea sounds sensible if it could work but hasn't been offered. Forgive my ignorance but can you explain further? The key fob has three main functions, right? a) Remote central locking powered by its internal battery b) Communication with the immobiliser and starter via the fob's transponder connecting to the antenna ring c) Physical connection via the ignition barrel. What is the function of a valet key (just point c?) and how does it play into this? Thanks.

 

Thanks. Can you be more specific? Are you talking about the ignition barrel itself, or part of it, or something else? Nobody from Volvo in France has suggested this.

 

With a test light and the car malfunctioning (i'm guessing the starter does not operate) see if there is 12v on terminal 30 and then 12v on terminal 50 with the key in the start position. A valet key has a chip (that the car is programmed to recognize) and is cut to turn the lock. It might be fatter and not work in the glove box. There are plain rubber handle keys Volvo sells that fit all the locks in your car. (that were used prior to the switchblade style)

 

If the starter won't crank and it's brand new and this is intermittently happening , as long as all connections are tight ( I had intermittent no crank because of improper connections once.tightening the connection of power wire made it all go away) then I'd put a modest bet on the problem being in the ignition switch....of course a voltage test verifies this ,but I'm pretty sure position three puts power directly to starter ,so it's only fair go assume there's where the problem is.i would be very wary of this dealers basic understanding of your cars ignition system.hope this ends up solving your problem, I mean thats what these forums are for!

 

This is the OP's original post. Since then good parts have been replaced without proving they are bad. And of course a wallet is getting much smaller, a brain is getting more frustrated and the problem still not fixed. What has not been mentioned - is a discussion of scanning the car with an appropriate scan tool, preferably VIDA. That would be the first step, not guess and replace. Sure test and verify is a good diagnostic process - but antenna rings and usually starters are not erratic and should only be replaced when you can prove they test bad.

What has not been mentioned is the common problem of a water damaged CEM in a xc90. Common failure symptoms courtesy of xemodex.

 

If you examine the wiring diagram posted earlier in this thread - the ignition switch 3/1 in the diagram sends a start signal (12v) directly to the CEM. The CEM will send a start signal via the ECM (with some engines) to activate the starter relay if a few conditions are met. Most basic conditions are - Car in park, neutral or clutch in if a manual (that info from the TCM) and immobilizer has okayed the key.

Gone are the days of using your test light to follow current flow from the battery to the fusebox to the ign switch to the neutral starting switch to the starter like you could in a 122,140,240,740,940,960 Volvo. (and previous cars)

 

It's a long story but the Volvo garage at Agen originally told me they couldn't help because they'd lost their mechanic and another one isn't joining until into the month of May. They did supply the parts which were fitted at a local (non-Volvo) garage. The suspicion that it was the antenna ring or the starter came from a variety of sources, including these forums but was not confirmed by a Volvo diagnostic as it should have been. On return to the Volvo garage on Monday, they were able to run a diagnostic, the output from which they showed me and which indicated the need for a new key although the person who ran the diagnostic and showed me the output was not 100% confident in its conclusion. The diagnostic didn;t indicate an ignition switch failure but I don't know what parameters they were using or whether they had the knowledge to use the diagnostic system competently. Car battery is good (< 2 yrs old), key fob battery replaced, ignition/immobiliser fuse replaced, relay in engine compartment checked and OK, starter, solenoid and antenna ring all replaced. This obviously all boils down to the lack of capability of the Volvo dealership in Agen and I guess I'll probably never know whether travelling a couple of hours to Bordeaux or Toulouse would have fixed things at an earlier stage.

The other symptoms of water ingress you've listed aren't being experienced on my particular car (which by the way is a D5 automatic) so whether it's the CEM or not remains to be seen. But the ignition switch seems to be an obvious possibility which they have not considered and if the new key doesn't fix the problem I'll be asking them why not.

Thanks for the input so far.

 

The ignition switch is not an obvious possibility. It's a random guess! With the appropriate scan tool you can tell if the immobilizer has approved a start. You can test the switch easily with a test light if your scan tool does not show an attempted start.

As I mentioned earlier - in 40 years I have never replaced a Volvo ignition switch because the starter function failed to work.