TPA800 parking sensors

[smartchap]

So I had a chance to spare some time to look around last weekend. I measured voltages and resistance on the normal two pin connector, the green one didnt read anything as it were a floating pin, no voltage or continuity to ground. The gray one was live wire powering the LED light. However, I did manage to use the programming wire to read out different menus, all other things seem to check out except for the only registered error of front sensor no.1 faulty.
Now I'm confused, both my front and back sensors dont work. However, without any registered error for rear sensors, I expected at least back sensors to work. the flip switch for back sensors dont seem to do anything although both button and wiring is intact. Fuses are ok.
I though the two pin connector would have one powering LED and other would be ground with push button to switch modes, but the gray wire both powers the LED and according to its location is also pulled to ground when button is pressed. This is working fine on the programming wire where I grounded this wire to readout system menus but I'm not ready to ground the other gray wire on normal connector which reads 12V till I'm completely sure.

So for now, at least for rear sensors, I'm not sure whether they're not working due to sensors issue or due to button being missing.

Is there any sure shot way to test out sensors? I can see above sensors are mentioned to be daisy-chained but wiring seems to suggest otherwise.

 

[Tractionman]

I wonder if someone has had the large n/s plastic side panel off before and disconnected/pulled off the wires to the rear sensor switch ?
Front an rear sensors are obviously 2 different systems.
Karl2000 has a method of testing individual sensors.

 

[smartchap]

No, the rear sensor switch and wiring is intact and ok till ECU. Can you link the sensor testing method you mentioned? I did search earlier but didnt find it or are you referring to feeling with fingers?

 

[Tractionman]

Finger method (ooer) and that 'crackling' feeling.
I think Karl is snowed under with work at the moment, but will be back in due course.

 

[smartchap]

Hello, i did the check with the multimeter and pulling that one wire to ground was the only thing that happened when the button was pressed. Without the button pressed in, no action on any wire.

Its a spare on my shelf, if you want it just PM me your address but it will be a week before i can send it. Dont want any £ just please update with your findings!

So its been a long time but I've managed to sort out issues as well as sensors, working a little bit here and there over some weekends. Now the thing is, I've manually verified complete front and back wiring including sensors and replaced that were faulty. Now there are no error codes or warnings but the system still dont work. Now the only thing missing is that front button with LED and I think it might not be activating due to this missing signal.

@karl2000 can I take you up on that offer for the switch as I cant find any replacement here. I'll pay for it too..

 

[karl2000]

Sure PM me your address details

 

[smartchap]

Odd, but I can't find how send message here

 

[Tractionman]

Small envelope top right of page, click on, type in recipient and start a conversation.

 

[smartchap]

sent

 

[karl2000]

Sent - let us know how you get on

 

[smartchap]

Thanks. Fingers crossed