TPMS RDC Module

[AndyS]

Hi all,
I recently have had TPMS failure messages randomly flag up on the iDrive and then disappear with no intervention on my part.
When I had new rear tyres fitted a few months back, I was advised the valve stems were showing their age and I assumed the error could be connected so was planning to replace them when I have my wheels refurbed in the spring.
At the beginning of last week the TPMS error became a permanent fixture and then, fairly shortly afterwards, all sorts of other intermittent issues occurred such as central electronics failure flagging up, dashboard warning lights flashing on and off, bouncing gauge needles etc etc.
My first thought was tired battery as it was the original one and nearly 8 years old. I know dodgy batteries can cause all sorts of issues on BMWs so have replaced that, unfortunately with no change.
I've now checked error codes and the one which caught my eye was A3C3 RDC Failure, the RDC being the main module for TPMS. I've also watched several YouTube videos which show different model BMWs with similar electronics/warning light issues and the RDC module was the culprit in those cases too.
Apparently this can be 'proved' by disconnecting the module and all the other electronics issues should disappear.
My problem is, I have no idea where the RDC module is located on a 2016 E89 and I can't find anything to help on the Internet.
Can anyone help with where it might be so I can check this out?

Thanks in advance for your help
Andy

[B21]

Looks like it sits in the boot..

[AndyS]

Thank you for your help.
Looks promising. I'll check tomorrow and report back.

[matsmith749]

'Bouncing guage needles' is the key indicator for something the canbus line being out of whack. Anything wrong on ths bus can trigger all kinds of madness across everything else that is connected.

Something like ISTA will be able to pinpoint which module it is if you have access to it? I don't think a standard code scanner will help too much.

[AndyS]

Most of the issues I'm seeing are intermittent, the only constant being the TPMS error which is what makes me think it could be the RDC module.
Sadly I couldn't find it in the location suggested by B21 so still no idea where they've hidden it.
Unfortunately I don't have access to ISTA either so I think I'm getting close to having to admit defeat and go to the dealers.

Andy

[B21]

Try this…

[AndyS]

A quick update.....
Not knowing what on the car might not be working properly, I haven't been driving it and could do with it back on the road.
I contacted a dealership in the hope they might be kind enough to tell me where the RDC module was so I could disconnect it and safely drive the car to them for repair. They said they weren't sure, it could be anywhere.
I contacted my local independent and asked the same question. He laughed and said it could be anywhere, sometimes even BMW don't know where they've put them.
So today I'm taking the car to the independent, very carefully, for them to diagnose the fault and continue with what appears to be BMWs version of "Where's Wally"
Thank you for your help and suggestions and I'll let you know the outcome once it's sorted.

[AndyS]

So, my car is fixed.
It was the RDC module at fault and apparently their diagnostic system pointed to the module being next to the fuse panel but turned out to be behind the rear bumper as suggested by B21.
Apparently, very difficult to reach without removing the bumper even on a ramp let alone crawling under the car on the drive!
Anyway, now all sorted so thank you for your help

Andy

[B21]

So, my car is fixed.
It was the RDC module at fault and apparently their diagnostic system pointed to the module being next to the fuse panel but turned out to be behind the rear bumper as suggested by B21.
Apparently, very difficult to reach without removing the bumper even on a ramp let alone crawling under the car on the drive!
Anyway, now all sorted so thank you for your help

Andy