Hi,

This is my first post and I hoping someone might be able to point me in the right direction. I've searched over the forums but couldn't find what I needed to know, so thought I'd start a new post.

My 2009/10 XF 3.0D S has developed an intermittent fault with the parking sensors. I start the car, put it in reverse and I get the long beep telling me there's a fault. But it's only intermittent.

I can't test to hear if the sensors are 'clicking' as I can't put the car in reverse without the engine started - otherwise the selector just recedes back into the console and automatically puts the car back in park, thereby turning them off - so I don't know how to best test this since the noise of the engine/exhaust is too much to hear the sensors themselves.

Similarly, when the system does go faulty, it's also a case of I'm thinking the system just turns them off, so pressing the 'sensor on' button in the roof lining does nothing but make that light flash to remind you that it's not working.

So because of its behaviour, and the fact it's not a constant fault, I'm thinking it's potentially a command module fault with the park assist module itself. But try as I might to find it, I have no idea where the parking assist module is located.

Is anyone able to shed some light on this for me please? (The park assist module location that is) And also confirm if my logic may be on the right tracks with thinking the module is most likely the cause because of the intermittent nature and the fact the whole system just stops working, or if it's a case of just one faulty sensor will also cause the whole system not to work too.

Many thanks for your help.

 

In case of a fault the whole system is disabled. The module is "I think" somewhere near the left wheel arch, maybe alongside the sat nav unit and power amp. I would check all tge connections first.

 

I don't have a copy of the XF Workshop Manual but the Parts Catalogue diagram indicates the Control Module is in the RH footwell. (probably behind a protective panel)

The on-board diagnostic routine within the control module on XF/XJ/XK models constantly monitors the system and alerts the driver to a system fault by emitting a 3 second continuous tone when the ignition is switched on. I think this is probably the intermittent warning you are hearing.

Unfortunately, other than obvious causes such as physical damage or blockage of one or more sensors there is little more that can be done without diagnostics other than check the harness connections.

The fault tone should have set a DTC (Diagnostic Trouble Code) which can be retrieved with dealer level diagnostics to pinpoint the source of the error.

Graham