I am hesitant to call this an 'issue' but I am also aware that I've had nearly two years of perfect motoring in the TDV8 so it's time something started to give.......

Just the past few days, when I put her in reverse I'm getting a solid (forward) tone as if the front bumper were close to an obstacle - but it's not. Then, after a couple of seconds, it all goes quiet and the PDC light above the switch starts to flash. I haven't been brave enough to test if the system is still working or not as we still have too much snow about and it's usually dark.

Any ideas?  The older I get, the more I realise that people confuse wrinkles for wisdom

snow, ice, and water play havoc with the parking sensors , i would say that its one or the other..test each sensor by listening to each one and if you hear a clicking then that sensor is working, if not try to dry it using a hair dryer.. ... - .- -.




Y. O. L. O.
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Your PDC ECU has detected a fault in the system and has disabled it.

From the Owners Handbook:

If a long, high pitched tone sounds and the switch indicator light flashes when PDC is activated, then a fault in the system has been detected - contact your dealer for assistance.

If you car is plugged in then there will be a fault code logged for the garage to work from.

Steve 06MY 4.4 V8 Autobiography Cairns Blue with Navy & Parchment Interior

Like ^he^ says moisture in the small black circle which freezes interferes with the ultrasonics. Mine have been a bit hit and miss since the cold snap. Warmth sees them work OK.

@ stevegt - many thanks for that extract. But what's an owners manual?

Yes, we have had our fair share of snow and ice. I can still loose a 12" ruler in white stuff across parts of my back garden.

Not inclined to visit the dealer specially for this - especially since its a >500mile round trip!  The older I get, the more I realise that people confuse wrinkles for wisdom

I have seen similar on a friends L322 and I had no idea what was wrong.

Not that it helps but mine is at the dealers with this at the moment. (as well as a leaky rear diff)

They RECKON they checked all sensors and the ECU and it's a wiring fault. I think it's a sensor given that it started when everything was well below freezing and hasn't been right since.

Ill update you when I know more... Or get the car back and fix it myself!

when i brought mine the rears didnt work and this was down to broken wires on the off side which i was told is a common problem, wires mended and all working well since. ... - .- -.




Y. O. L. O.
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Suffered the same problem with the RRSport sensors in wintery weather - road salt seems to have a detrimental effect on them too 2018 Mini Countryman Cooper S E All4 PHEV in Melting Silver - it’s whisper quiet in EV and polluter modes

can also be a short in the system, mine went like that when a cable broke

From the workshop manual:

The PDC ECU performs a self test and a system integrity test every time the system is selected on (either by selecting reverse of by pressing the button on the centre console).

If a fault is detected the ECU isolated either: the front sensors, rear sensors or both front and rear sensors.

the driver is informed of the fault by a long beep (instead of the short one) and a Flashing LED (at 2 hz if anybody is that interested).

So when you select the system on and you get the fault indications do you still have the use of any sensors? Front or rear?

If you can still use the front ones logic would dictate that the issue is with the rear system and vice versa for the rear ones. However if both are isolated then it gets a little more tricky. It could be the ECU has a fault, both systems are faulty or something else completely.

Either way you will not be able to use the PDC until you have the fault code read as it is latched and stored in the non volatile memory of the PDC ECU and is read through the iBus system and the instrument pack.

Hopefully the fault code will give you a steer and you will be able to fix it. However the PDC is notoriously fickle and difficult to find faults. If you have money to throw at the problem then ask the garage to remove the bumper for the system at fault (eg front or rear) and get them to test that the connectors are being powered. This confirms the integrity of the wiring. Then you could try a new ECU (these are £95 and are common across all FFRR and do come up on eBay like this one). Then I would try swapping sensors around to eliminate duff sensors. Unfortunately you cannot just by a new harness for the PDC sensors as the front ones are wired into the main engine bay harness and the rear ones are part of the rear lights harness (I think). So if it is wiring it will need to be repaired.

All of this is fairly simple really and can be done by a brave amateur, it just takes time. A dealer will charge a full 1 hrs labour to remove and refit the front bumper, I did it in under 30 mins on my first attempt. If you do try a new ECU it is just plug and play, no configuring required. Dan has just bought an X5 ECU for £25 to try. He probably wont receive it until the New Year but it will be interesting to see if it works. Although there are a lot of common parts the PDC unit doesn't have any BMW markings at all despite looking identical.

There is no point listening for clicking sensors at the moment because the PDC ECU has turned the sensors off. Until you get the code(s) read there is nothing more you can do.

Sorry to be the bearer of bad news...

Steve 06MY 4.4 V8 Autobiography Cairns Blue with Navy & Parchment Interior

stevegt wrote:

Either way you will not be able to use the PDC until you have the fault code read as it is latched and stored in the non volatile memory of the PDC ECU and is read through the iBus system and the instrument pack.<snip>Until you get the code(s) read there is nothing more you can do.

Thank-you for this Steve. However, I have some interesting news which doesn't concur with the above.......

Yesterday, (ambient temp above freezing) I selected reverse and everything worked as normal. Tested both front and rear sensors with success!

Methinks 'something' doesn't like the cold......  The older I get, the more I realise that people confuse wrinkles for wisdom

Posting from +32c Malaysia ............................... JMC could you have had any water freeze over any or one of the sensors or a lot of road dirt taht has been washed off by you 2018 Mini Countryman Cooper S E All4 PHEV in Melting Silver - it’s whisper quiet in EV and polluter modes

Nothing in front of them Tim. Sensors have all been clean / ice-free when this problem occurred.  The older I get, the more I realise that people confuse wrinkles for wisdom

you are probably getting water inside the sensor, my son has just had this problem with his bmw sensor.. ... - .- -.




Y. O. L. O.
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