rear wiper Rear wiper stopped working

[KDM]

Hi.

 

My 2011 Octavia rear wiper was intermittent for a while then stopped working.

All the fuses are fine.

Before I go and spend anything from £40 to £80 on a new motor, I'd like to convince myself the problem's not elsewhere. I'm handy enough with a multimeter, but I can't find a pinout for the motor, so I don't know which of the 45 (!) wires to probe (or inject 12V to test).

Also, with the motor disconnected, I don't know if I should see anything on the harness. In the "olden days" (20 years ago) the wiper motor had a rotary switch built in so it recognised the end of travel, so I don't know if it's stuck partway and "thinks" it's on...

 

Any ideas where I can find a  pinout, or how to debug, please?

 

Thanks.

[J.R.]

It wont be of any use to you, its a canbus node, the switch does not conduct voltage to the motor in the manner that you are expecting, it pulls up or down a signal current from the body or comfort control module, this sends a coded signal via canbus to the node in the rear wiper motor which controls the motor.

 

You have 2 large wires for 12V and earth, then a twisted pair for the canbus network.

 

If you strip the motor you can hotwire it via the large contacts, you can also measure the continuity of the self park switch.

 

Its usually siezed up through water ingress, I got mine working but it failed again after a few months, a replacement is quite cheap and is plug n play, requires no coding.

[KDM]

1 hour ago, J.R. said:

It wont be of any use to you, its a canbus node

 

That makes 100% sense. I mentioned the 57 wires and the hankering for the "olden days".

I'd have thought, at that rate, the OBD should have flashed up a problem...

 

I'll give it a bit of a jiggle and see what happens. £40-£80 is quite a bit for something which might not fix my problem! AND with my luck, I'll order the wrong thing.

 

Haha. Your signature. I'm "Normandie, sometimes Worcestershire."

[J.R.]

Soon it will be changing to "Nouvelle Aquitaine, sometimes Sussex, sometimes Picardie" and then to "Nouvelle Aquitaine, sometimes Picardie" and then hopefully to "Nouvelle Aquitaine" only.

 

Life has to get more complicated before it can get simpler.

 

You would not get a generic OBDII fault code for a non mission critical control module, VCDS would flag up a non comms or intermittent comms situation but there is no sensing hence feedback from the motor, it's told what to do and it either does it or it doesn't or it does it slowly/intermittently.

[KDM]

Dammit, so just the same as Internet of Things devices. Message broadcast. Maybe it gets acted on, maybe it doesn't...

OKay. Splash the £40 then. Thanks.

[pikpilot]

30 minutes ago, KDM said:

Splash the £40 then. 

 

Just a note to say the hatch and estate have different rear wiper assemblies so they are not interchangeable. Check against your part number or model if buying online.

[KDM]

On 02/11/2021 at 22:31, pikpilot said:

Check against your part number or model if buying online.

There must be about 10 different parts which claim to be compatible and a few which look identical, but which claim not to be compatible.

Do you know how the parts numbers work? Many of them seem very similar. Mine is 1Z9 955 711 B ZA3. The 1Z9 and teh ZA3 are often different. (Maybe they aren't part of the part number?) and sometimes the B is a C.

Do I need  part with an absolutely identical number?

[Guest]

Hatch or estate?

[pikpilot]

The last letter is the revision letter so use the same letter or later.

 

The biggest difference is between hatch and estate. The hatch has the washer feed going through the wiper shaft and the estate does not as it has washer jet build into the high level brake light.

 

When mine failed on my facelift estate, it was replaced with part 1Z9 955 711 B; no reference to ZA3.

[KDM]

17 hours ago, MicMac said:

Hatch or estate?

Yeah, they have completely different part numbers. This is the estate. Irritatingly, the one I want is on eBay, but eBay garage says it's not compatible. I think it's mistaken. I might take a punt.

[Guest]

https://www.ebay.co.uk/itm/373786452394?hash=item570768a1aa:g:SgoAAOSwtKFhizmU

[KDM]

12 minutes ago, MicMac said:

https://www.ebay.co.uk/itm/373786452394?hash=item570768a1aa:g:SgoAAOSwtKFhizmU

I looked at that one. I was sceptical as mine doesn't have the metal back. I took a punt on a £30 one. We'll see on Tuesday!

[Brissy]

On 03/11/2021 at 04:55, J.R. said:

It wont be of any use to you, its a canbus node, the switch does not conduct voltage to the motor in the manner that you are expecting, it pulls up or down a signal current from the body or comfort control module, this sends a coded signal via canbus to the node in the rear wiper motor which controls the motor.

 

You have 2 large wires for 12V and earth, then a twisted pair for the canbus network.

 

If you strip the motor you can hotwire it via the large contacts, you can also measure the continuity of the self park switch.

 

Its usually siezed up through water ingress, I got mine working but it failed again after a few months, a replacement is quite cheap and is plug n play, requires no coding.

Hi I am having the same problem, you have already swerved a few question. The unit works if I put power on it via the 2 out side pins. In the connector the 2 out side pins are 12v & negative is that correct, then the 2 middle pins are signalling as you pointed out ? How an I test if I am getting a signal? What is a canbus node and where would I find it? Or look like 

youhelp would be appreciated 

[Breezy_Pete]

See this thread, some of wire colours and pin numbers at BCM may differ between Yeti and Octy2, but the gist is the same.

Will check Octy wiring later to confirm. No CAN node involved. 

https://www.briskoda.net/forums/topic/511807-2010-yeti-rear-wiper/

 

[J.R.]

1 hour ago, Brissy said:

Hi I am having the same problem, you have already swerved a few question. The unit works if I put power on it via the 2 out side pins. In the connector the 2 out side pins are 12v & negative is that correct, then the 2 middle pins are signalling as you pointed out ? How an I test if I am getting a signal? What is a canbus node and where would I find it? Or look like 

youhelp would be appreciated 

 

Work on your people skills and it will be forthcoming.

[Breezy_Pete]

I suspect the 'swerved' was an auto-correct from an intended 'answered'?

[Breezy_Pete]

Octy2 May 2011> diagram, pin numbers at 5-way connector looks like the only significant difference to the diagram in the link I posted earlier. See last comment from me in that linked post for my best guess at how the signalling/control works. If you could confirm, that would be awesome. (Assistant operating stalks and a voltmeter at rear wiper will be required).

 

 

[Brissy]

Thanks for your answers

[Guest]

@Brissy

 

If your car doesn't have maxidot, confirm locking via key remote works and boot lights extinguish.

 

If the boot closed sensor is faulty the rear wash/wipe won't work.

[Brissy]

I got it working thanks to those helpful people for parting with your knowledge. You have been a big help.

 

[Breezy_Pete]

15 minutes ago, Brissy said:

I got it working thanks to those helpful people for parting with your knowledge. You have been a big help.

 

What was the problem?

[Brissy]

The back door wasn’t closing properly, the latch had come loose. Adjusted and it was good. 

On 08/06/2023 at 16:38, Breezy_Pete said:

What was the problem?

 

[Breezy_Pete]

Nice one @MicMac. 

[bobxmerrison]

My rear wiper motor has packed up, can anyone recommend a reputable source (not Skoda) for a new motor please?

Thanks

[Brissy]

Is the motor gone or is it jammed, the mec sticks. You can pull it apart and clean it.