I have an 04 XC90 with high-performance audio and the 6-CD in-dash changer unit. Suddenly, the CD player is no longer available and the infotainment unit acts as though it is just a radio. It also no longer comes up with the "high performance audio" message upon switching on- it just goes straight to the radio. The CD buttons do nothing, including the eject button, so my CDs are now lost in the unit. There are no nasty noises from the unit, and no error codes, so it is not as if a CD has become stuck.

Does anyone have any ideas as to what might be causing this? And more importantly, what I can do about it?

TIA...

I've also noticed that the parking sensors have stopped working at the same time- any ideas?

Did you get the CD player problem resolved? I am having a similar problem with mine and noticed that there have been a few posts on this but no resolution to the problem.

Well, the car had its annual service last week, so I asked the garage to take a look at the problem. Apparently the ICU (infotainment control unit) is reporting a low voltage- an internal fault that apparently can only be rectified by a full replacement for the princely sum of just over £1000.
(IMG:style_emoticons/default/sad.gif)

Time to find someone to hack the ICU to pieces and repair it, I think...

I've had my High Performance Audio system apart this weekend so I have a couple of ideas for you to try.

Firstly, the CD unit is a separate device from the rest of the audio system. For those who aren't familiar with it, the audio in these cars consists of a power amplifier under the driver's seat (in RHD configuration), a display and controls in the centre of the dashboard, a CD drive below the display and controls, and a radio tuner in the ceiling at the rear of the car.

All of the components of the audio system are powered from the wiring loom in a fairly conventional manner, but are connected to each other by fibre-optic cables. The fibre cables transport the control signals and the audio as digital information which is converted to analogue by the amplifier before being amplified and then sent to the speakers.

This introduces the possibility that the CD player can go wrong without affecting the rest of the system. I suspect your fault is not related to the controls, display or amplifier because they are functioning correctly for radio operation.

To confirm this, try removing the cable connector from the back of the CD unit while the ignition key is set to Accessories and the audio system is either on or off. If you look at the fibre cable connector that you've pulled out of the CD player, you will see two dots that are the ends of the fibre cable. One should have a slowly flashing red light coming out of it. That is from the amplifier, trying (I presume) to establish a connection with the CD player. If there's no flashing light, try turning on the audio system (if it's off). Try turning the ignition key off and then back to Accessories. If there's still no flashing, then there's nothing coming from the amplifier and I suspect the problem lies there. If there is flashing, I suspect the problem is in the CD unit, in which case you will need to remove it and try to fix it.

The CD unit can be unscrewed at its front and withdrawn from the front of the plastic basket of audio components. Inside the large Volvo-stamped box there is probably a smaller box that is the actual CD drive (a CD changer in your case). I say 'probably' because my Australian-delivered car only has a single CD unit and it was built in the way I describe. Perhaps the CD changer is larger, but I doubt it.

In the calm environment of your home, unscrew the lid of the Volvo box and gently remove the ribbon cable connecting the CD unit to the circuit inside the Volvo box. You will notice a circuit board in the Volvo box - it is the thing that converts the Volvo digital fibre-optic system's signals to/from the CD unit's signals. I suspect that the circuit board in the Volvo box is faulty in your case. I don't know if it'll be repairable, but at this point you can at least retrieve your CDs. To do this you will need to dismantle the CD unit. I've never done that to a CD changer so I can't offer any advice, but I expect it's certainly possible. But be careful.

The fault in your Volvo interface board could be as simple as a dead capacitor or something. Inspect it all carefully and decide if any parts look fried. If they are, replace them. If not, I'm running out of ideas. I know there's a place in Bath that repairs these things (mapleaudio.co.uk) so you could try them.

Of course, the fact that you mentioned failed parking sensors could mean you have a more serious fault and it makes several of my paragraphs unhelpful. Hopefully though, after fixing the CD unit you'll have everything back to normal again. It wouldn't surprise me if there's a daisy-chain arrangement between the parking sensors, CD player and display/controls or something like that. I know my stereo kept going just as a radio when I removed the CD player, but I didn't try reversing while it was in that state.

If it is the ICU, I suspect that's the circuit board behind the radio display. In that case, I'd try pulling it apart and checking its components too. Maybe one of them is simply fried and needs replacing.

Good luck, and if you need more instructions on removing the unit from the dashboard, please ask. I can do it almost blindfolded now.

My 04 XC90 has the same combination of problems--parking sensor stopped working, CD player no longer recognized, radio comes on intermittently, no messages on the screen. I'm taking it to the dealer next week to get it checked, and am dreading the amount of $$$$ they'll charge me to fix it. How were you able to resolve your issues?

Philip76- thanks for the detailed reply. The garage were quite clear that the ICU was reporting a fault, and the problem manifests in the parking sensors as well as the CD player, which seems to confirm that. Nevertheless, you have inspired me in due course to take the car to bits rather than pay >£1000 to allow Volvo to line their pockets with what is probably a sledgehammer-to-crack-a-nut solution of replacing the entire unit.

Unfortunately time and "calm environment of own home" are not in easy reach with a house-full of children that justified buying the car in the first place (IMG:style_emoticons/default/smile.gif) but when I get a free afternoon I intend to pull the unit out. Rather than fiddle inside the ICU myself (my days of dabbling with soldering irons are behind me), I'll send it off to the guys at http://www.bba-reman.com/uk/ who over the phone claim to be able to investigate (and hopefully fix) the unit.

When I get around to this I'll post back to let you know how I got on...

Well, I took the ICM out the other day, and that prevented quite a lot of the car from working: as well as obviously the radio and parking sensors, there was no operable central locking, remote locking, air conditioning/heating/screen heater, so with the childlock, it was impossible to get into the rear of the car! Obviously this makes the vehicle pretty unusable as a family car. Sadly this means that I won't be sending it for repair, and now it is time to give up and find a dealer to fix it for ££££ (IMG:style_emoticons/default/crying.gif)

Also, after putting everything back again I now have an "airbag service" warning message, which I suspect is due to disconnecting the climate control module without disconnecting the battery. Despite that Volvo service manual instructions on ICM replacement don't mention that little snippet. Great...