How do you enable parking sensors on a C5?

[Dommo]

Hi all

I have a 2007 mk1 facelifted C5 VTX+ which never came with parking sensors. I found an exclusive in my local scrapyard and managed to get it's bumpers with parking sensors, and the ECU that sits in the spare wheel well, as well as the control panel with the parking sensor on/off button.

We managed to get the panel, rear bumper and ECU fitted today, but it hasn't exactly fired into life, which is to be expected as I'll have to enable it with Lexia. So on that note I've fired up Lexia and changed the following settings:

Presence of parking assistance button - yes
Type of parking assistance - Front and rear and measurement of available space (unsure if this was the correct choice!)
Parking assistance with visual information - yes (I have the colour nav display as it's a VTX+ model)
Parking assistance with audible information - yes
Presence of a faulty parking assistance warning - yes

I also set it to say it does have a parking sensor ECU in the ECU presence page.

Have I missed anything here or have I just chosen the wrong options? The Exclusive spec car I had the parts from does not have the nav display, if that matters. On servicebox I can see that the ECU appears to need to be programmed, but I assumed what I'd done in lexia would have sorted that out.

Cheers folks, Dom.

[GiveMeABreak]

For a start there is no parking space gap measurement on the MK II, so that shouldn't even be an option - that was only for the X7 MK III.... Are you configuring the correct C5?

[Dommo]

Hi Marc

If I'm honest I was unsure what that option meant. I was pretty sure I'd seen parking distance on a mk1 facelift nav screen before so I assumed that was what I was setting there.

If you look at the following attached photo you can see my Lexia display and see that it says "NEW LOOK CITROEN C5" at the top, which is what a mk1 facelift shows up as.

[GiveMeABreak]

I've had a MK I, MK II and MK III and only top trim X7s have the parking space gap measurement. On the X7, with front & Rear Parking assistance and gap measurement, there is an additional sensor on each of the front left and right bumper skirt shown below as items (6) & (11). These are the sensors that measure a parking space when enabled inside using the button to see if the car will fit.

It was never fitted on the MK I or MK II C5s. These only had a maximum of 4 front and 4 rear sensors, which is why I asked about the configuration being there....

Was all the wiring there?

[wheeler]

You may also need to enable it in the multi function display and/or the radio head unit.

[Dommo]

Interesting, thanks for that Marc.

Yes the loom was sat there ready to be used just taped up behind the boot carpet on the drivers side (UK car). So if I try changing the measurement of available space to just be 'front and rear parking sensors' (or similar) then that would be the correct choice there I suspect. I will say I've not fitted the front bumper yet, but electrically the ECU is connected up, I would have expected some life from it, albeit lots of bonging and beeping due to the front sensors not being connected up yet.

Thanks for that idea wheeler, I'll see how we get on tomorrow after fitting the front bumper and will keep you all posted.

[GiveMeABreak]

Yes, change that option for sure - not sure why it's there unless it's another poor translation from them!

[Dommo]

Hi again all.

After getting in the car ready to fit the front bumper yesterday the system fired into life with an error, which made sense as the front bumper wasn’t fitted yet.

Now the front bumper is fitted we have a parking sensor error on the dash and have only the following error in Lexia:

Is this sounding like the outer right rear sensor has failed, or is it an incorrect setting in Lexia?

For the record I haven’t yet changed the distance measurement setting.

Thanks all, Dom.

[GiveMeABreak]

This is the rear outermost sensor having a short circuit to positive. The supply voltage of the sensor is above the authorised threshold. Whilst this fault is active and in common with any sensor (front or rear), the whole system is disabled. So you need to check the harness or the sensor is faulty.

[Dommo]

This is the rear outermost sensor having a short circuit to positive. The supply voltage of the sensor is above the authorised threshold. Whilst this fault is active and in common with any sensor (front or rear), the whole system is disabled. So you need to check the harness or the sensor is faulty.

Thanks for that.

I figured that was the best course of action. I was just checking if that particular fault code was specifically loom related or sensor related, but if it could be either the best bet would be to move the sensor into another position and see if the error moves with it. So that’s what we’ll do when we get chance.

Thanks Marc, Dom.

[GiveMeABreak]

The issue with these is that water penetrates the back of the sensor where the wiring enters the sensor. I had quite a few go in successive months one after the other at the rear - the cause was water ingress, so be careful with anything that will worsen the seals. In my case they re-routed the rear sensor harness below the sensors to prevent accumulated water dropping down the wiring and into the back of the sensor area. If yours is ok, it may just be a faulty sensor.

[Dommo]

Hey again Marc.

I’ve switched the parking sensor on the external right rear to the inner right rear position and the fault moved with it, safe to say the sensor is the faulty component.

Regarding a replacement, am I best getting a known good used part, or a ‘knock off’ part from eBay or the like? I’ve seen a new in box Citroen sensor for £27 which seems reasonable but is that the suggested best repair course of action here? Do you know what the original cost of an OE sensor should be?

Thanks very much. Dom.

[GiveMeABreak]

Just be aware that the MK I, MK II and X7 (MK III) have different sensors.

If you need an official part number though it will mean a membership upgrade Dom, details below:

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[Dommo]

Thanks Marc. I don’t need any part numbers for this. The old sensor had the back completely missing so I suspect someone had looked into it before I pulled the bumpers from the scrapyard.

I’ve sourced a replacement sensor and the error reported by Lexia has gone away, however the system still flags a parking assistance system faulty in the colour display, with no faults logged at all on Lexia.

I altered the BSI settings to remove the measurement of space setting to see if that was the difference and now the system doesn’t respond at all, which is a bit odd. No errors, just nothing at all from it. The parking sensor ‘off’ switch still lights up if pressed so it’s not completely dead.

I suspect I need to find someone with a mk1 facelift with the colour display and parking sensors to see what settings are enabled on their BSI. It can only be bad programming on my part.

Thanks for your advice this far Marc.

[Dommo]

Some progress here for anyone interested, I hadn't enabled the sensors within the telematics system (colour nav screen), since doing that I now have fully functional rear sensors and mostly functional front's - so there is still work to do there, but someone on a C5 page elsewhere has given me something to try. If it works I'll be sure to post up on here what exactly was required to get them working with his permission.