2012 L322 RR Aux input noise

[Mbarba]

Hey everyone,

This is my first post on this forum. I only entered the Land Rover world a few months ago, and honestly it has been wonderful so far. Not sure why I didn’t buy a Range Rover earlier!

I’m looking for some advice because I’ve been dealing with an issue for almost a month now. I sent the car to a very reputable local shop here in town, British Car Service, and they’ve been great, but they still haven’t been able to pinpoint the problem. They referred me to an audio specialist, but I honestly think this may be more of a known Land Rover issue or bug that someone here may have already experienced.

The Problem​

I have a buzzing/static noise coming from the speakers whenever I switch to the AUX input. As soon as I plug in a jack cable, the noise appears. It seems much more noticeable through the upper speakers than the larger lower door speakers.

What I’m Installing​

I’m currently installing an external CarPlay module. The module taps into the OEM Satellite Receiver/Radio Module located in the passenger footwell behind the fuse box.

Here’s the module:
https://unique-ad.co.uk/product/wir...-l320-range-rover-l322-discovery-4-2009-2012/

It’s actually a really cool system, and I’ve already installed the exact same setup on two other L322s without any issues.

The system requires using the rear AUX input (rear entertainment media AUX connection in the back of the center console) in order to feed audio from the CarPlay module into the factory audio system.

Most importantly: I’m 100% sure the issue is NOT coming from the aftermarket module itself because the noise remains even after completely removing the CarPlay setup.

What I’ve Diagnosed So Far​

• I swapped the rear entertainment AUX input module (rear center console unit) with another known working unit from a different car. The noise remained.
• Even when I completely unplug the rear AUX module (both connectors disconnected), the noise is still there.
• The ONLY time there is no noise is when nothing is plugged into the AUX jack.
• I removed the AUX fuse (I believe fuse #51), and the noise disappeared.
• When I unplug the second connector from the OEM Satellite Receiver/Radio Module (which I believe may be the speaker output connector), the noise disappears again.
• If I disconnect any fiber optic connection from the MOST loop (rear trunk/CD changer area), the noise also disappears — but then of course I lose audio completely.

I circled in RED the connector where unplugging it stops the noise.

My Thoughts / Questions​

• Could this be a ground loop issue somewhere in the AUX system?
• Could the factory amplifier be failing?
• Does anyone know the exact amp location on these trucks?
• Has anyone experienced this exact issue before?

What’s strange is:

• CD audio works perfectly
• FM/AM radio works perfectly
• The buzzing ONLY appears when using AUX

I honestly have no clue at this point and I’m genuinely stuck.

Any guidance would be hugely appreciated. Thanks everyone.