No volume control from radio or steering wheel

[Rupert Gladwin]

I am having an issue with my e46 where I am unable to hear any sound coming from the speakers and I am not able to adjust the volume by using either the radio or the steering wheel. I have done tests on the speakers and I know they are working but I'm not sure what may be stopping any sound from coming from any of the speakers and not being able to adjust the sound. If you could help it would be much appreciated.

[Muzz258]

The E46 got different stereo spec's for different markets and models of the car.

Which one did you get in your E46?
- CD 53 head-unit and no amp
- CD 53 with an Amp
- Radio and amp in the boot with remote control head unit in the cabin.
- Navigation system
- Something else?

[Rupert Gladwin]

CD 53 hu and no amp

[Muzz258]

The steering wheel controls use I-Bus to talk to the head unit. If it was the I-bus, then other items would not be working properly, such as the Air Con system. I suspect that the problem is the head unit, as the volume knob is not working.

I take it that you have tried a CD to rule out a faulty radio aerial/diversity amp in the left side C pillar.

[Rupert Gladwin]

The AC seems to work fine and I have tested it with multiple head units so I dont think it's that. But now you mention the diversity amp I haven't thought of that. How would I go about testing that?

Really appreciating the help ��

[MarcoZandrini]

The problem is in the head unit if the volume knob does nothing. Likely the internal amp isn’t getting power as all channels are mute. Do all other head unit functions work? That is, can you tune to different radio stations? Find the fuse card. It’s in the fuse panel above the glove box. See how many fuses supply power to the head unit. In E46s sold in the US there are 2 fuses. Also, pull the head unit to see if there’s a fuse at the back of the unit. It may have blown.

[Rupert Gladwin]

I have checked all the fuses and they are all fine. I dont believe it is the head unit as I have tried using a different one with the same result. All head unit functions work but there is no sound.

[Muzz258]

Hi

If you are having the same problem with 2 different head units and there is not sound when trying to play a CD, then its likely not the head units.

Diversity Amp
It is not likely to be the problem as you have no sound when playing a CD.

Fuses
As mentioned by others, check all fuses and the one behind the head unit connector.

I-Bus
You may have a faulty volume button on the steering wheel, which may be lowering the volume all of the time. Pull pin 7 (i-bus) from the connector on the back of the head unit and try it again. See attached pin-out diagram. Use a small pick to hold back the tabs on the pin and you can withdrawal the pin out of the back of the connector. Remember that pin 7 still has 12 V DC on it, so insulate it and don't let it touch earth, your you'll have other problems to sort out.

Telephone Mute
Don't know if your E46 is set up with a phone or not. Pull pin 4 on the head unit connector and see if it solves the problem. Again, treat the removed pin as live 12 V DC and insulate it.

[Rupert Gladwin]

Really appreciate the replies I'll go and do some of the tests and get back to you with the results. Thanks again

[Rupert Gladwin]

I have gone back and done the cd test and the sound did not work(kinda as expected). I disconnected the number 7 pin but still had no success with any kind of sound. I double checked all my fuses and they are all fine. I honestly have no idea what the problem could be.

[Rupert Gladwin]

I would also like to add that the radio doent keep a time saved after the engine is turned off so could it be that it is not getting powered from another wire when it's off and because of that no working?

[MarcoZandrini]

Hmmm, does the instrument cluster show the correct time? I think the head unit gets time info from the cluster though I may have it backwards. The head unit gets power from fuse 7 (5 amps, always on) and fuse 41 (30 amp switched power). Now, bc your car has the amp in the head unit the second fuse may be a different amperage. Also, there’s a fuse at the back of the head unit. However, I think that if that fuse is blown the head unit is inoperable. Real head scratcher.

[Ccotb2714]

I would also like to add that the radio doent keep a time saved after the engine is turned off so could it be that it is not getting powered from another wire when it's off and because of that no working?

Did you ever figure out why there was no sound in any head unit you hooked up but power was there I’ve gone through every step you did and had the same result please reply if you solved your issue im going crazy!!🥺