807 front parking sensors not working

[Romtag]

Hiya All

Recently bought a 807 with front and rear parking sensors.

I have worked out that the front ones don't appear to work as I accidentally kissed the wheelie bin with the car yesterday .

Has this happened to anyone else or does anyone have any ideas as to how I could fix it.

The rear ones one fine..

Thanks

[GiveMeABreak]

This is unusual - if there is a fault with any part of the parking assistance detected by the PA ECU, usually the whole system goes inoperative as a safety measure. The ECU is stored in the rear right wing inside the side panel, so it should be safe to assume this has not been affected.

Can you pop your VIN up (automatically masked from public view on post submission) and I'll be able to confirm what system you have.

[Romtag]

VF3**************[VIN obfuscated, can be read by forum staff] I think that's right!

[GiveMeABreak]

Ok, so just confirmed that the vehicle was factory fitted with both front and rear parking assistance.

1) Can you confirm whether the front system has ever worked in your ownership?
2) Can you confirm whether the rear sensors are also functioning (but don't be crashing into the wheelie bin!).?
3) When you engage reverse gear, does the system throw up any messages (like 'Parking assistance faulty')? or does it show the reversing sensors on the main display and issue a beep?
4) Ditto for the Front sensors.

If you are not aware of the front ever working - there is the possibility that the previous owner had one or 2 sensors need replacing and instead of dong that may have disabled the front system. To do that, the configuration of the system would have had to be changed from Front & Rear to Rear only parking assistance, using Diagbox or another suitable tool. The other possibility is that the wiring block for the front parking assistance sensors has been unplugged from the ECU I mentioned. Having said that and until I get your answers on the above points, unplugging the connector with the front sensors in would also disable the communication with the whole ECU to the BSI as the same 18 pin plug holds the front sensor connections and the CAN communication wires to the BSI. The separate 12 pin plug only connects the rear sensors.

[Romtag]

Hi,

1, Only owned the car for 6 days... never worked during those days.
2, Yes rear sensors work fine.
3, When entering reverse it shows the car and I get a single beep
4 Get nothing for front sensors at all.

To be honest I dont think he looked after the car at all. So it could be any of the issues you have outlined.

Thanks Marc

[GiveMeABreak]

Ok, so that was helpful.

1) If the rear is working, there is a possibility that the previous owner has had issues at some point and replaced the parking assistance ECU with the version designed for rear parking assistance only. That would be most likely reason why the system is not throwing up a wobbly - as it is not expecting or has no inputs for the front sensors.

[Romtag]

Ok... How do I go about checking that. is it easy to take the panel off in the back

[GiveMeABreak]

All I can tell you is it is on the rear left internal wing - you may need to get behind the lining - here:

[Romtag]

Is that rear left or right? I'll have to find a guide/manual on taking the panels off.

Thanks again Marc, worth your weight in gold!

[GiveMeABreak]

Offside rear

[Romtag]

Thanks

I will mooch around and see what I can find out on how to take the internal trim off.

[Romtag]

Finally got round to checking this parking sensor ECU.

ECU box

I wonder if the lack of front sensor has something to do with the hatchet wiring job I have discovered!

[GiveMeABreak]

Ok, so I've just done some research for you looking at a Russian breakers of one of these with the exact same module and part number; checked against that vehicle's VIN and it was also fitted with front and rear sensors - so the good news is you have the correct ECU

Now as for the spaghetti, you may have to trace the Parking assistance connections back to see if those breaks you discovered where from this or something else.

I will put up a wiring diagram shortly for you of the parking assistance to help you trace this.

[GiveMeABreak]

Here's the Main Diagram, with 7500 being the parking assistance ECU.

So in your picture, the Blue connector is for the rear sensors
The Black Connector handles the Front Sensors and the CAN network wiring.

The 18 Pin Black Connector shown on the right of the unit of the diagram below (18 V NR) is the one you want to be tracing.



The wiring from the Parking ECU seems to tie back into harness 46 HAB and then back to the BSI



Some Diagrams showing the locations:

[Romtag]

And that's the point my head explodes at

I think I will have to print them out at work..

Weird that I don't get any errors on the system though.