For some reason my reverse park distance control is sometimes not engaging when I select reverse.

Luckily I have a switch I can use to engage the PDC, so its not a massive problem, but I'm not sure why selecting reverse is only engaging the PDC intermittently.

Its not dodgy sensors as I've tested them all and PDC kicks in happily when I press the button, so I'm thinking its something to do with the park distance controller?

I will get it scanned on VCDS when I can get to my mate who has it, but in the meantime, does anyone have any ideas what to look into please?

Thanks in advance

Adam

Do you have front parking sensors as well?

The switch is for turing on/off the front sensors only.

I know of another member retro fitting front and rear PDC and he fitted the rear sensors and contoller first. But system would not work until he had wired up the fronts and the switch.

So could also be problem with front sensors or the switch which is causing problems with the rears.

Hope that helps.

Thanks. Yes I do have front PDC too, but the light on the switch comes on for the reversing sensors when all seems to be functioning properly. I think the switch is mainly for turning the front sensors on when approaching something without having reversed in the same manouvre, but it also seems to kick in the rear sensors when the reverse gear does not.

Do your reversing lights work?

Maybe the parking controller gets signal from the reverse switch and that could be faulty?

Defintely worth a check, I'll look into it, thanks.

Could be the switch that detects whether the vehicle has been put in reverse (wherever that is).

Do you have a Columbus or Bolero with the hidden menu activated?

If you do, go to the relevant 'Can' section and engage reverse to see if the 'Can reverse' changes at all. That will clarify whether the Can knows reverse is engaged or not and whether it is sending out the right signals.

The button can be used to activate PDC (front & rear) if moving forward into a tight space or to deactivate PDC if it's not needed (like when reversing up my drive when going from flat to sloping ground).

Interesting, I'll also give that a try as I do have Columbus with hidden menu....

Thanks

Adam

Canbus detecting the reverse and the lights apparently working so at a bit of a loss now!

If it works when you press the button I don't see how it will be the controller!

It sounds as though the signal is not getting from the Can to the PDC controller reliably.

Possible wiring issue?

Mmmm hope not! Time to get the VCDS on it I think

It would be cheaper (but a lot harder to find) if it was the wiring as opposed to the controller...

Indeed. Having said that surely the switch and the reverse gear use the same wire..

The switch has two earth wires, an illumination wire and the rest (3) are wired back to the controller.

There is a wiring diagram on this forum somewhere. I have no Internet at home otherwise I'd post the picture here.

Thanks. From what you say the switch is a circuit that is independent of the reverse gear electrics. If so the controller presumably gets an alternative feed from the reverse light circuit to activate the PDC. So given my reverse lights work, and the switch works, it seemingly can only be a wiring fault between the reverse lights and controller. As it happens I cannot now get the fault to occur, when it does next I'll get a multimeter on that feed to the controller. Does anyone know where I'd find the controller please? Around the boot somewhere I'm guessing?

Adam

When you engage the Reverse Gear, a "CAN Message" asking it to come ON, and when the Gear is disengaged, another Message to put it OFF is sent over the CAN Bus (Cable) that is connected to the Controller from the CAN Gateway (Master Controller). These messages are exchanged over the CAN Bus from the Gateway to the Controller over a pair of Wires (Cable). The Parking Switch you are referring to is connected directly to the controller to activate/de-active it without having to use the CAN Bus. Since the Switch activation of the PDC works perfectly, it would most probably be a problem with the CAN Cable that is connected from the Gateway to the PDC Controller as it seems the Messages are not reaching the PDC all the time. VCDS would come in handy in confirming this.

The Controller is easy to locate, which can be found inside the trunk, on the Passenger's side:

That is great info - thanks mate.

Adam

Do you have front parking sensors as well?

The switch is for turing on/off the front sensors only.

I know of another member retro fitting front and rear PDC and he fitted the rear sensors and contoller first. But system would not work until he had wired up the fronts and the switch.

So could also be problem with front sensors or the switch which is causing problems with the rears.

Hope that helps.

Hmmm, not on mine it isn't. It turns on/off the lot.

Intermitten faults! I love those....

Get a VCDS scan done with someone who knows where to look for the PDC specifics (I need to check myself do can't advise at the mo) as the general scan will only aid in what the problem is (but at least that's a start).

Does sound like a wiring problem from the CAN to the PDC where the signal is not being sent to the controller reliably.

The switch is wired to the controller;

Switch sends signal reliably;

The controller sends signal to CAN reliably;

BUT the CAN doesn't send signal to PDC reliably!

Works one way but not the other!

This is beyond me now....

Yeah I definitely need to get VCDS on it. Incidentally why do you believe "The controller sends signal to CAN reliably"??

Adam

Yeah I definitely need to get VCDS on it. Incidentally why do you believe "The controller sends signal to CAN reliably"??

Adam

I don't, I only think it is a potential problem, because it is a good place to begin with. There could be many more problems like the switch connected to the Gear might be defective, the Controller might itself be faulty (at this particular function), etc.

Start by connecting a VCDS and then upwards.

Sorry hell666 that was a question to KBPhoto following his comment, but yes I'm booked in with my mates VCDS later this week.

Incidentally why do you believe "The controller sends signal to CAN reliably"??

Because there is only one connection between the controller and the CAN and every time you press the button it works!

My logic says that it's not the CAN wiring from controller to PDC (or vice versa if you stand at the back of the car!) otherwise you would experience problems with both methods of activation.

I'm no auto electrician though!

Ok thanks.