location of the tpms (rdc) module

[heatmizr]

Is there an easy way to disable the TPMS system in the meanwhile, to avoid getting the intermittent "Malfunction" message? Like pull a fuse or something? This gets really old on long trips.

[H16bill]

Found it. Poking around under the car and located it in the rear of the vehicle between the muffler and the differential. Unhooked it and tried car. Same tpms malfunction. Opened the sealed box. Found corrosion present on the circuit board. Seems there is a vent that lets moisture in. Cleaned up the circuit board with alcohol and a toothbrush. Still same fault. Took it for a drive, all other faults cleared but still tpms malfunction.

[heatmizr]

OK I found it too. Its a little bigger than a bic lighter.
Its easy to see in its bracket on the frame, and labeled "REIFENDRUCK - KONTROLLE". The wiring merges with a larger harness and then to the back of the passenger rear wheel well.

I did same test as you, unplugged it and started car, got the "TPMS Malfunction Warning" and gong, flashing dash light and iDrive error message.
The plug connections looked clean but sprayed them out with WD40 and blew them dry, re-installed, started car, no error. Drove around for 20 mins and got the error 3 times. So no change.

So either this second replacement TPMS module is defective like the first (unlikely) or I have a loose wire that intermittently breaks the connection.
Do they have a diagnosing method to trace that issue if its in the wiring or CAN-BUS? This sounds difficult (expensive) when the issue is intermittent. It only seems to stay disconnected and issue the warning for ~10 secs at a time.

PLAN A - unplug and tape up the connections, and drive around to see if the gong and flashing light on the dash subside after a minute. If YES, this is how I will drive the car on some upcoming long trips. That gong and flashing light drive me nuts. One solid dash light on, I can deal with.
I will do this tonight/tomorrow to confirm.

PLAN B - Will need new tires soon, and its time to change the wheel sensors too. I guess I can HOPE there is a chance that with new wheel sensors the issue is magically resolved, but I am not holding my breath. Dealer states that would leave error codes that they did not see.

Anyone know what code / error message would be shown if the module was intermittently losing connection to one or more wheel sensors? Same as above or different?

[heatmizr]

PLAN A - Confirmed.
The module is sitting on my bench in the garage, and at each start I get the gong/flashing warning light for TMPS Malf. After a minute those stop and I am left with a solid TPMS light on the dash, fine. Looking for a little sticker to put over that for my upcoming long trips.

I'll still try PLAN B when I get tires.

This will have to suffice until I take the vehicle in for one of the outstanding recalls, at which time I will ask that they hunt it down.
I was warned last time, that wiring issues would not be covered under the CPO warrenty, and having them track down a loose wire might be costly.

[heatmizr]

GOOD NEWS
The TPMS MALFUNCTION error that has been plaguing me has been Vanquished!
4 new TPMS sensors in the wheels seems to have solved it. 2 weeks and 2k miles since my tire service and No Errors!

Seems the dealer was wrong - no faults were registered from any sensors, as they said would be the case. Occam's Razor - the simplest explanation is most likely the correct one.

[740iS]

Anyone have a picture of this sensor location? I've tried crawling under there but didn't see it. Is it behind a shield or something? Have replacement, but need to know where to put it.

[Qsilver7]

Originally Posted by 740iS

Anyone have a picture of this sensor location? I've tried crawling under there but didn't see it. Is it behind a shield or something? Have replacement, but need to know where to put it.

From new TIS website...there appears to be two types (one is named "low cost")...once you go to the page...click on the one you need:

https://www.newtis.info/tisv2/a/en/e...control+module

[heatmizr]

Wait, the one I discussed above in my posts is not the same one as in those links.
Mine was on the front side of a frame rail running left to right between the diff and the muffler. Very easy to spot, labeled as I wrote in an above post.
I don't know which component 740is is looking for. And I can't speak to what the components are that Qsilver posted; those appear to be under the hood (I didn't recognize those location diagrams).
I *think* mine is an antennae and the others are actual RDC modules. But I am not sure by any means.

[740iS]

The link that Q posted has a link to the "Low Cost" sensor and that is the antenna that is between the muffler and the differential, part number 36236771043. I'll be going under this afternoon to hopefully find and replace it. New wheel sensors didn't fix it for me.

Thanks Q for the link. I'll try to take a pic of it too when I find it.

[Qsilver7]

Originally Posted by 740iS

The link that Q posted has a link to the "Low Cost" sensor and that is the antenna that is between the muffler and the differential, part number 36236771043. I'll be going under this afternoon to hopefully find and replace it. New wheel sensors didn't fix it for me.

Thanks Q for the link. I'll try to take a pic of it too when I find it.

(pic below from link for LOW COST TPMS)

https://www.newtis.info/tisv2/a/en/e...-rims/FCVcPPJi