No power to stereo and sat nav.

[Tony500]

My partner was dropping our son on at nursery the other day and said the sound on the radio cut out about 10 seconds after starting the car.... I thought it was the usual operator error but sadly not.
No today there is no power to the stereo and sat nav and the parking sensors don't work and that's a big thing for the other half.

I have checked the usual fuses ect a d they are all good nothing blown....

What can I check next? Is this a common fault of the dreaded icm failure?

[john langrick]

Hi, certainly sounds like the ICM. If this fails, so will satnavl and park sensors.

I would start by checking the MOST bus. This is the fibre optic loop to take a fibre optic signal generated at the ICM head (where the display is). If that is not working or the loop broken, then will have these symptoms. The loop passes through all modules, satnav, amplifier, aerial module, sub woofer (if you have one), etc, but loops back to the ICM.

If you remove the connector from rear of satnav, you should see a light in one of the 'pins'. No light and you probably have an ICM issue. If there is a light on one of the 'pins', then check for kinks or breaks elsewhere. You can also buy a loopback connector that will loop the optic signal straight back to the ICM. This could isolate a faulty module other than the ICM.

If it is ICM, I can recommend Volvo diagnostics' who will replace your ICM on an exchange basis and the replacement will have a lifetime warranty.

Hope this helps.

John l

[Tony500]

Thanks John, I've looked at all wires ect and they are all in good shape...
I checked with a test lamp and there is no power to the back of the unit?

I will get in contact with the company you have recommended, thanks .

[Tony500]

I need help with this one.... I've removed the ICM from the car but the heating stays on and the car doesn't lock. I've contacted Volvo diagnostics and paid just had to send today but couldn't.

Why does this system have to be so complex.

[Tony500]

Received an email today from Volvo diagnostics and my ICM is working fine. What else could be the cause 🙈🙈

[paddy74]

Did you check with VIDA for DTCs? That would be my first step, as anything else is just guessing.

[Tony500]

I've not yet with Vida but my Autel said communication to ICM module missing and is a permanent fault. 1A66.

[paddy74]

I'd try to read it out with VIDA again, maybe there are more (or more specific) DTCs.
Next step would be to check the wiring between CEM and ICM, and while you're there, check the CEM for corrosion, especially the plugs.

Sounds like an annoying search, I know, but if the ICM is ok, it must be something else along the road.

[SwissXC90]

If no power then check relay on CEM

[Tony500]

Originally Posted by SwissXC90

If no power then check relay on CEM

What relay is it I'm looking for? I cannot find a diagram. Thanks